Doc #59 — Bicycle Fleet Management and Expansion

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RECOMMENDED ACTIONS (BY ACTUAL URGENCY)

Happens automatically via fuel rationing (first days):

1. People start cycling because they cannot drive — no government intervention required for initial modal shift

First weeks to months:

2. Include bicycles and bicycle parts in the national asset census (Doc #8) — establish actual numbers, types, and condition
3. Centralize bicycle tire, tube, and spare parts stocks from retail channels (bike shops, warehouse retailers, online retailer warehouses). These are Category B consumables (Doc #1) — important but not same-day urgent
4. Establish community bicycle repair workshops in every significant settlement, including marae-based workshops that serve both local communities and passing cyclists — can be staffed by trained volunteers, not specialist mechanics
5. Issue public cycling skills guidance — many NZ adults cannot cycle confidently or safely in mixed traffic
6. Identify and protect all bicycle shop inventories, including specialty tools (spoke wrenches, chain tools, bearing presses, truing stands)

First 3–6 months:

7. Begin separated cycle lane implementation on major urban routes (paint, concrete planters, timber barriers — no major construction required)
8. Establish cargo bike and trailer fabrication program at engineering workshops and welding shops
9. Conduct e-bike battery inventory and establish charging/management protocol
10. Begin bicycle mechanic training program (short course — 2–4 weeks for competent basic maintenance; 3–6 months for full workshop capability)
11. Assess rail and ferry integration points — design bicycle-to-rail and bicycle-to-ferry transfer infrastructure

First year:

12. Prototype NZ-manufactured bicycle frames from Glenbrook steel tube (Doc #89)
13. Begin chain manufacturing trials (requires precision metalworking — Doc #91)
14. Establish regional bicycle parts depots and a parts exchange system
15. Deploy cargo bikes and trailers for community logistics — grocery distribution, mail, light freight

Years 2–5 (Phase 2–3):

16. Scale bicycle frame production
17. Develop bearing manufacturing capability (hardest component — see Section 7)
18. Establish NZ-produced tire alternatives (solid rubber from recycled stock, or eventually from imported natural rubber via sail trade)
19. Expand bicycle-rail integration across the network
20. Develop bicycle ambulance and emergency response capability for areas without vehicle access

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ECONOMIC JUSTIFICATION

The transport arithmetic

The comparison is not bicycle versus car under normal conditions. It is bicycle versus no transport at all, because the car fleet is being consumed by irreplaceable tire, fuel, and parts depletion.

What a bicycle replaces. For trips under 10 km — which covers the majority of urban daily travel and many rural trips — a bicycle provides roughly equivalent door-to-door times compared to a vehicle at recovery-era speed limits (30 km/h urban, 60 km/h open road). A cyclist averaging 15–20 km/h versus a driver averaging 20–25 km/h after parking and congestion is not a significant time penalty.⁵

Freight comparison. A single bicycle with a trailer (100 kg capacity) making 10 km return trips can move 300–500 kg per day, consuming only the rider’s food energy — approximately 300–400 additional kilocalories above resting metabolism per hour of moderate cycling.⁶ Moving the same freight by truck consumes approximately 3–5 liters of diesel per 10 km loaded trip.⁷ At recovery fuel values, the bicycle is not competitive with a truck in capacity per trip, but it is infinitely competitive in terms of fuel cost: zero petroleum versus irreplaceable petroleum.

Investment cost. Setting up one community bicycle workshop: approximately 40–80 person-hours to establish the space, organize tools, and train the first cohort of volunteer mechanics.⁸ This is a modest investment relative to the transport utility it enables. By comparison, converting one truck to wood gas requires approximately 200–400 person-hours of skilled fabrication work (Doc #56).

Fleet-level economics. If 500,000 bicycles are brought into regular daily use (a conservative assumption given 1.5–2.5 million in the existing stock), each replacing an average of 15 km of vehicle travel per day, this displaces approximately 7.5 million vehicle-kilometres daily. At average vehicle fuel consumption of 10 liters/100 km, this saves 750,000 liters of fuel per day — roughly 3% of NZ’s pre-event daily petroleum consumption.⁹ More importantly, it saves tires and vehicle parts that are not being consumed.

Person-year investment for national bicycle infrastructure program:

Component	Person-years (estimate)
Community workshops (200 nationwide)	2–4
Mechanic training (1,000 trainees)	10–15
Cycle lane infrastructure (major urban centres)	20–40
Cargo bike/trailer fabrication (1,000 units)	5–10
Frame manufacturing pilot (Phase 2)	10–20
Total first 2 years	~50–90

This is modest compared to other recovery programs. For context, the wood gas conversion program (Doc #56) for 5,000 vehicles requires an estimated 40,000–100,000 person-hours of skilled fabrication, and the vehicle fleet management program (Doc #6) requires continuous staffing of hundreds of personnel.

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1. NZ’S EXISTING BICYCLE STOCK

1.1 Estimated numbers

NZ imports approximately 300,000–400,000 bicycles per year.¹⁰ Assuming an average functional life of 8–12 years with substantial attrition to non-use (stored in garages, rusted, donated, exported), a standing stock of 1.5–2.5 million bicycles in some condition is plausible. The number in immediately rideable condition is significantly lower — perhaps 800,000–1.5 million. The remainder would require repair ranging from minor (flat tire, seized chain) to major (bent frame, missing wheels, seized bearings).

This estimate is rough. The actual number, type distribution, and condition must be established through the national asset census (Doc #8).

1.2 Type distribution

NZ’s bicycle stock is skewed toward recreational types:¹¹

Type	Estimated share	Utility for transport
Mountain bikes	35–45%	Good — robust, geared for hills, wide tires tolerate poor surfaces
Road/racing bikes	15–20%	Moderate — fast on good surfaces, fragile for loaded use, narrow tires
Hybrid/commuter	10–15%	Excellent — designed for utility, comfortable geometry
Children’s bikes	15–20%	Limited — not useful for adult transport, but important for youth mobility
BMX/specialty	5–10%	Limited — single-speed, small wheels
E-bikes	3–5%	Excellent while batteries last — see Section 5

Mountain bikes are the most useful starting platform for recovery transport: they have wide-range gearing for hills, robust frames and wheels, and tires that tolerate poor surfaces. NZ’s strong mountain biking culture means the stock of mountain bikes is large and often well-maintained.

1.3 Geographic distribution

Bicycles are distributed roughly in proportion to population, with higher per-capita ownership in cities with cycling culture (Christchurch historically the strongest cycling city in NZ, followed by Wellington, Auckland, and smaller centres like Nelson and Napier-Hastings).¹² Rural areas have lower bicycle density but also lower transport needs per trip — though trip distances are longer.

Canterbury Plains advantage. The Canterbury region around Christchurch is one of the few large flat areas in NZ, and Christchurch has historically had NZ’s highest cycling rates. Under recovery conditions, Canterbury becomes a natural bicycle heartland — flat terrain, existing cycling culture, and the established road network makes cycling practical for both commuting and light freight.

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2. TERRAIN: NZ’S GEOGRAPHY AND CYCLING

2.1 The terrain problem, honestly stated

NZ is not the Netherlands. Much of the country is hilly, and some of it is extremely hilly. This is a genuine limitation on bicycle utility that cannot be wished away.

Wellington is among the hilliest capital cities in the world. Many suburbs (Kelburn, Karori, Khandallah, Brooklyn, Island Bay’s hills, the Hutt Valley surrounding ranges) involve sustained gradients of 5–15%. A rider carrying 20 kg of groceries up a 10% grade at 8 km/h requires approximately 150–200 watts of sustained power output — achievable for a fit adult, but exhausting for an elderly person or someone carrying a child.¹³

Dunedin has similar challenges — steep streets, cold southern weather, and a compact urban core surrounded by hillside suburbs.

Auckland is gentler in many areas but the isthmus geography creates bottlenecks and hills between key areas.

Smaller towns throughout NZ are frequently built on hilly terrain. NZ’s topography is fundamentally a product of tectonic activity — flat land is the exception, not the rule.

2.2 Where cycling works well

Canterbury Plains: Christchurch and surrounding towns sit on the flat alluvial Canterbury Plains. This is by far NZ’s best cycling geography — flat, with a grid road network, and an existing cycling culture that Christchurch has maintained since the 19th century.

Waikato and Hauraki Plains: Hamilton and surrounding dairy country are relatively flat. The Hauraki Plains around Te Aroha and Paeroa are well-suited to cycling.

Manawatu: Palmerston North and surrounding area are flat to gently rolling — viable for cycling.

Hawke’s Bay: Napier and Hastings sit on a relatively flat coastal plain with an established cycling culture (the region promotes itself as a cycling destination).

Coastal towns: Many smaller NZ towns (Blenheim, Timaru, Whanganui, Gisborne) have flat or gently sloping town centres near sea level, with hills beyond.

2.3 Adapting to hills

For hilly areas, several strategies partially mitigate the terrain challenge:

Low gearing. Mountain bikes already have gear ratios as low as 22:36 (front:rear), providing approximately a 0.6:1 ratio that allows climbing steep gradients at very low speed. Modifying bikes to have even lower granny gears — by fitting larger rear sprockets — extends climbing capability further. This requires specific sprockets and chain compatibility; a trained bicycle mechanic can perform the modification in 1–2 hours with appropriate parts.¹⁴

Route selection. Flat or low-gradient routes often exist as alternatives to the steepest roads. NZ’s existing cycling advocacy groups (Cycle Action Network, regional cycling groups) have already mapped low-gradient routes in many cities. These maps should be preserved and expanded. In rural areas, sections of Te Araroa and older trail networks that follow river valleys and coastal paths may offer more direct or less hilly alternatives to the modern road network — though many sections require surface improvement before they can support loaded cycling.

Staging points at hill bases. For steep hills that cannot be avoided, goods can be staged at the base and transported uphill in smaller loads, or by different means (hand cart, pack animal). Residences at the top of steep hills may use a combination of cycling on flat sections and walking/cart on the hill.

E-bike deployment on hills (while batteries last) — see Section 5.

Acceptance of limitation. Some Wellington hillside suburbs will never be practical cycling environments for loaded transport. Residents may need to relocate to lower areas, or accept that their transport reality involves walking and hand-carrying rather than cycling. This is a quality-of-life reduction, not a crisis — people lived in these suburbs before cars existed, using walking and (in Wellington’s case) cable cars and trams.

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3. TIRE AND TUBE MANAGEMENT

3.1 The rubber dependency

Bicycle tires share the same fundamental constraint as vehicle tires: they are made from rubber compounds that NZ cannot produce (Doc #33). However, the scale of the problem is dramatically different. A bicycle tire weighs 300–700 grams and lasts 3,000–10,000 km depending on type, surface, and load.¹⁵ A car tire weighs 8–12 kg and lasts 40,000–80,000 km. Per kilometer of transport, the bicycle uses rubber at roughly one-fifth the rate of a car.

3.2 NZ’s bicycle tire stock

NZ’s bicycle shops, warehouses, and online retailer distribution centres hold an uncertain but probably substantial stock of bicycle tires and inner tubes. NZ imports approximately 400,000–600,000 bicycle tires per year as a rough estimate based on bicycle import volumes and replacement demand.¹⁶ If in-country stocks represent 2–4 months of normal supply, this suggests approximately 70,000–200,000 tires in the distribution chain at any time. Additionally, many cyclists keep spare tubes and occasionally spare tires at home.

Estimated total bicycle tire stock:

Category	Estimated quantity
Tires in distribution chain (shops, warehouses)	70,000–200,000
Tires on bicycles (1.5–2.5M bikes x 2 tires)	3–5 million
Spare tubes in households and shops	100,000–300,000
Total tires	~3–5 million

The tires currently mounted on bicycles constitute the large majority of the stock. Many of these are in serviceable condition, though tires on unused garage bikes may have dry rot or cracking.

3.3 Extending tire life

Proper inflation. Under-inflation is the primary cause of premature bicycle tire failure and pinch flats (where the inner tube is pinched between the tire and rim). Bicycle pumps — both floor pumps and portable pumps — should be maintained and distributed. A floor pump with a pressure gauge is an essential tool for every community bicycle workshop.

Surface avoidance. Glass, sharp gravel, thorns, and metal debris cause punctures. Regular sweeping of primary cycling routes reduces puncture rates significantly. This is a small investment of labour with a large return in tire and tube preservation.

Tire rotation. Rear tires wear faster than front tires (the rear carries more weight and provides drive force). Rotating tires front-to-rear when the rear tire is half-worn evens the wear rate across both tires.

Speed management. Tire wear increases with speed due to higher scrubbing forces in turns and braking. At the speeds most recovery-era cycling will occur (10–20 km/h), tire wear is relatively low compared to high-speed road cycling.

Load management. Overloaded tires wear faster and are more prone to puncture. Cargo should be distributed across trailers rather than concentrated on a single bike.

3.4 Puncture repair

Puncture repair is one of the most important maintenance skills in a bicycle-dependent transport system. Inner tube patching requires minimal tools and can be taught in under an hour:

• Locate the puncture (inflate tube, submerge in water or feel for air)
• Rough the surface around the puncture with sandpaper or a scuffer
• Apply vulcanizing cement (included in standard patch kits)
• Apply patch, press firmly, allow to cure
• Reassemble tire and tube on rim, inflate

Patch kit supply. NZ’s stock of bicycle patch kits is finite. The key consumable is vulcanizing cement — a rubber cement typically based on natural rubber dissolved in a volatile solvent (typically hexane, naphtha, or MEK). As commercial patch kits run out, alternatives include:

• Contact adhesive (less durable but functional for temporary repairs)
• Heat vulcanization using a hot patch and a heat source — bonds rubber to rubber without chemical cement. Requires a small heated press or iron and suitable patches. This is how automotive tire tubes were traditionally repaired and is more durable than cold patching.
• NZ-produced rubber cement — if solvents are available (ethanol or turpentine from local production could serve as carrier solvents), dissolved rubber from scrap tubes or tires can produce a serviceable cement. The quality will be lower than commercial products but adequate for tube repair.

3.5 Solid tire alternatives

When pneumatic tires are eventually exhausted, solid alternatives exist:

Solid rubber inserts. Recycled rubber from car tires (crumb rubber bonded with a binding agent such as polyurethane or, under recovery conditions, sulfur-reclaimed rubber using heat and pressure) can be molded into solid bicycle tire profiles. The binding and molding process requires a heated press and either imported polyurethane adhesive (finite stock) or a devulcanization setup using sulfur and sustained heat at 150–180°C (Doc #33). These are heavy, provide poor ride quality, and transmit every road imperfection to the rider. But they do not puncture and do not require inner tubes. The ride quality penalty is significant — solid tires on rough surfaces at 15+ km/h cause hand, wrist, and back fatigue that limits effective riding time. They are best suited for slow-speed utility cycling (under 15 km/h) on smooth surfaces.¹⁷

Airless tire inserts. Foam or lattice inserts that fit inside a standard tire casing, replacing the inner tube. These provide moderately better ride quality than solid rubber but still significantly worse than pneumatic — rolling resistance is approximately 15–30% higher than pneumatic tires, and vibration damping is inferior, though better than solid rubber.¹⁸ They can be fabricated from closed-cell foam (available from insulation materials) or potentially from natural rubber latex if trade supplies become available.

Leather or wrapped tires. Historically, before pneumatic tires (patented 1888), bicycles used solid rubber or leather tires.¹⁹ Leather tires wrapped around a metal rim provide modest cushioning on smooth surfaces. NZ has a substantial leather supply from its livestock industry. Leather tires are a last-resort option — they wear quickly (perhaps 500–1,500 km depending on surface and load), provide minimal cushioning, and slip on wet surfaces (a significant problem in NZ’s rainy climate). They are mentioned for completeness, not recommendation.

Honest assessment. All solid tire alternatives represent a significant performance degradation from pneumatic tires. Ride quality drops substantially, rider fatigue increases, speed decreases, and comfort on NZ’s often-rough road surfaces declines. This is the reality of substitution — it works, but it is worse. The bicycle remains far more practical than the alternative (walking or nothing), even on solid tires.

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4. DRIVETRAIN MAINTENANCE AND PRODUCTION

4.1 The chain problem

The bicycle chain is the component most vulnerable to wear and most difficult to manufacture locally. A modern bicycle chain consists of outer plates, inner plates, rollers, and pins — all made from hardened alloy steel to precise tolerances. A typical chain has 108–116 links, each with four components, totaling over 400 individual parts.²⁰

Wear mechanism. Chain wear is caused by elongation — the pins wearing against the bushings (or inner plates in bushless designs), gradually increasing the pitch beyond the nominal 12.7mm (1/2 inch). A chain elongated by 0.5–0.75% should be replaced — continued use causes accelerated wear on sprockets and chainrings, damaging components that are harder to replace than the chain itself.²¹

Wear rate. Depends critically on lubrication, contamination, and load. A well-lubricated chain in clean conditions can last 3,000–8,000 km. A poorly lubricated chain in dirty conditions may last only 1,000–2,000 km. Under recovery conditions where cycling is daily transport over mixed surfaces, with imperfect lubrication (see Section 4.4), chain life of 2,000–5,000 km is a reasonable estimate.

NZ chain stock. NZ bicycle shops and distributors hold an uncertain stock of replacement chains. A rough estimate based on normal replacement demand: perhaps 50,000–150,000 chains in the distribution chain at any time. This stock, combined with chains already on bicycles, provides a buffer — but chains are a consumable that will eventually need local production.

4.2 Sprockets and chainrings

Sprockets (rear) and chainrings (front) wear with chain elongation. If chains are replaced before 0.75% elongation, sprockets and chainrings can last through 2–3 chain changes — perhaps 10,000–25,000 km. If chains are allowed to stretch beyond this, sprockets and chainrings wear rapidly and must be replaced together with the chain.

Implication. Diligent chain replacement is not fastidiousness — it is a strategic decision that extends the life of harder-to-replace sprocket and chainring components. Every community workshop should have a chain wear gauge and enforce replacement discipline.

4.3 Bearing maintenance

Bicycles use bearings in the hubs (front and rear wheels), bottom bracket (pedal axle), headset (steering), and pedals. Modern bicycles increasingly use sealed cartridge bearings (often imported Japanese or Chinese units), while older designs use loose ball bearings in adjustable cups and cones.

Cup-and-cone bearings are more serviceable under recovery conditions. The balls can be replaced individually (standard sizes: 3/16”, 1/4”, 5/32” for most applications), the cups and cones can be re-ground or lapped when worn, and the adjustment is done with standard cone wrenches. NZ’s machine shops (Doc #91) can produce replacement bearing balls from steel stock, though the surface hardness and sphericity of locally produced balls will be inferior to manufactured bearings — increasing rolling friction and reducing bearing life.²²

Sealed cartridge bearings are effectively a sealed consumable. When they wear out, the cartridge must be replaced. NZ’s stock of replacement cartridge bearings (in bike shops and industrial bearing suppliers) is the only supply. Once exhausted, sealed bearing hubs must be converted to cup-and-cone systems (possible with machine shop work but not trivial) or abandoned in favor of older-design hubs.

Lubrication. Bearings require grease (cups and cones) or are pre-greased (sealed cartridges). As petroleum grease depletes, NZ-produced tallow-lime grease (Doc #34) can substitute for bicycle bearing grease. The performance gap is real: tallow grease has lower oxidative stability and will need more frequent repacking — perhaps every 1,000–2,000 km versus 5,000–10,000 km for petroleum grease. It also performs poorly in wet conditions, which is a problem in NZ’s climate. Adding lanolin (available from NZ wool scouring) to the tallow grease improves water resistance somewhat.²³

4.4 Chain lubrication

Chain lubrication is the single most impactful maintenance practice for extending drivetrain life. A dry chain wears roughly 3–5 times faster than a properly lubricated chain.

Current lubricants. Bicycle chain lubricants are petroleum-based (wet lubes) or wax-based (dry lubes), all imported.

NZ substitutes (Doc #34):

• Rendered tallow, filtered: Serviceable chain lubricant for dry conditions. Apply warm (liquid), allow to set. Reapply frequently (every 50–100 km, or after rain). Performance gap: attracts dirt, washes off in rain, becomes sticky in cold weather. But it works — a tallow-lubricated chain lasts much longer than a dry chain.
• Lanolin: Better chain lubricant than tallow — more water-resistant, less sticky. Apply warm. NZ produces significant quantities from wool scouring. Probably the best locally available bicycle chain lubricant.
• Tallow-beeswax blend: A mix of rendered tallow and beeswax (NZ has an apiculture industry) provides a drier-setting lubricant that attracts less dirt than pure tallow. Historical precedent: similar blends were used as machine lubricants before petroleum.
• Castor oil (if available): Superior to tallow for chain lubrication — better penetration, higher film strength, good at low temperatures. NZ does not currently grow castor beans, but cultivation is possible in warmer northern regions under future conditions (see Doc #34).

Application discipline. Under recovery conditions, the temptation is to over-apply lubricant (any is better than none). This is wrong for chain lubrication: excess lubricant attracts abrasive particles (dirt, sand) that accelerate wear. Apply sparingly, wipe off excess. Clean the chain periodically by wiping with a rag — solvents for proper degreasing will be scarce.

4.5 Local chain manufacturing

Manufacturing bicycle chain is the hardest component production problem for local bicycle independence. The chain requires:

• Steel strip of consistent thickness (cold-rolled, hardened): NZ Steel at Glenbrook (Doc #89) produces flat steel but the tolerances required for chain plate blanking are tighter than standard construction steel. Producing thin, consistent-gauge strip may require rolling mill modifications.
• Precision blanking or stamping of inner and outer plates: requires punch-and-die tooling machined to close tolerances.
• Pin wire of consistent diameter, hardened: requires wire drawing capability (Doc #105).
• Roller formation (in bushed chains): requires tube-drawing or deep-drawing capability.
• Heat treatment: Chain components must be case-hardened or through-hardened for wear resistance. NZ has heat treatment capability in existing engineering workshops, but quality control for consistent hardness across thousands of parts requires process discipline.
• Assembly: Chain assembly requires riveting pins through plates and rollers at consistent tension.

Feasibility assessment. NZ can produce bicycle chains, but not immediately and not easily. The dependency chain runs through NZ Steel (strip and wire stock), machine shops (tooling), heat treatment facilities, and assembly operations. A purpose-built chain production line — even a manually operated one — requires engineering development time. Realistic timeline: prototype chains in Phase 2 (years 1–3), with production quality improving through Phase 3. Early NZ-produced chains will likely be heavier, less precise, and shorter-lived than imported chains — but functional.

Alternative: single-speed conversion. For utility cycling, multi-speed drivetrains are a convenience, not a necessity (except on steep hills). Converting bicycles to single-speed eliminates the derailleur system (derailleurs are complex, fragile, and hard to manufacture) and uses a simpler, more robust chain configuration. Single-speed bicycles use a wider chain (1/8” versus 3/32”) that is somewhat easier to manufacture and more tolerant of imprecise components. The trade-off is loss of gearing, which matters significantly on NZ’s hilly terrain.

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5. ELECTRIC BICYCLES

5.1 NZ’s e-bike stock

E-bike sales in NZ have grown rapidly, with an estimated 60,000–120,000 e-bikes in the country as of 2024–2025.²⁴ Most use lithium-ion battery packs (36V or 48V, 400–750 Wh typical) and hub motors or mid-drive motors rated at 250–750 watts.

5.2 Strategic value on hills

E-bikes are the most effective mitigation for NZ’s terrain problem — but only for as long as batteries last. A 250–750W motor provides enough assist to make a 10% gradient manageable for a loaded rider. This transforms the utility of cycling in Wellington, Dunedin, and every other hilly NZ town.

Grid power is available. NZ’s electrical grid (85%+ renewable, hydro and geothermal backbone) is expected to continue operating (baseline scenario). Charging e-bikes from the grid is feasible and low-cost in energy terms — a typical e-bike charge (0.4–0.6 kWh) is comparable to running an electric kettle for 10–15 minutes.²⁵

5.3 Battery life and management

E-bike lithium-ion batteries degrade through both cycling (charge-discharge) and calendar aging. Typical useful life under normal conditions: 500–1,000 charge cycles, or 3–7 years of regular use, whichever comes first.²⁶ Under recovery conditions with daily use, batteries may last 2–5 years before capacity drops below useful levels (typically below 60–70% of original capacity).

NZ cannot manufacture lithium-ion batteries. There is no domestic production pathway for lithium-ion cells — the chemistry and manufacturing precision required are well beyond NZ’s current or near-term industrial capability (Doc #35). When the existing stock of e-bike batteries is exhausted, e-bike capability ends unless alternative battery chemistries are available.

Lead-acid conversion. NZ can produce lead-acid batteries (Doc #35). A lead-acid battery pack providing equivalent energy to a lithium-ion e-bike pack would weigh approximately 12–18 kg versus 2.5–4 kg for lithium — a significant penalty, but the bicycle can still be ridden, especially with motor assist compensating for the extra weight.²⁷ Lead-acid e-bike packs reduce range by roughly 40–60% compared to lithium for the same energy due to higher weight and lower charge/discharge efficiency, but they extend e-bike viability indefinitely as long as NZ can produce lead-acid batteries and electricity.

5.4 Priority deployment

E-bikes should be treated as strategic assets and allocated to highest-value uses:

Priority 1 — Hilly urban transport. Wellington, Dunedin, and other hilly towns where e-bikes transform cycling from impractical to practical. These are the locations where e-bikes provide the greatest marginal benefit over standard bicycles.

Priority 2 — Cargo and logistics. E-cargo bikes for community freight, medical supply delivery, and rural mail. The motor assist enables carrying 100+ kg loads over meaningful distances.

Priority 3 — Emergency and medical. Bicycle ambulances and emergency response in areas without vehicle access.

Priority 4 — Commuting on longer flat routes. Where trip distances exceed comfortable unassisted cycling range (roughly 10–15 km one way for most riders), e-bikes extend practical commuting distance to 20–40 km.

5.5 Motor and controller maintenance

E-bike motors (brushless DC, typically) are relatively robust — the motor itself has one moving part (the rotor) and no brushes to wear. Controllers, displays, and wiring are the more fragile components. NZ’s electronics repair capability (limited but extant) can maintain and repair controllers at the component level, replacing capacitors, MOSFETs, and connectors. When controllers fail beyond repair, salvage from other e-bikes extends the operational fleet.

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6. CARGO BIKES AND TRAILERS

6.1 Why cargo capacity matters

Recreational bicycles carry a rider and little else. For bicycles to serve as transport infrastructure — not recreation — they must carry loads: groceries, tools, building materials, agricultural supplies, children, medical equipment. The conversion from recreational to utility cycling is primarily about cargo capacity.

6.2 Bicycle trailers

The simplest path to cargo capacity is a towed trailer. Bicycle trailers can be fabricated from steel tube (mild steel, 20–25mm diameter round or square tube), standard bicycle wheels (20” or 26”), and a hitch that attaches to the rear axle or seat post.

Fabrication. A competent welder with access to steel tube, a grinder, and a drill can build a bicycle trailer in 8–16 hours.²⁸ The basic design — a rectangular or triangular frame, a plywood or steel sheet bed, two wheels on a common axle, and a hitch arm — is well within the capability of a competent welder, though achieving adequate load-bearing strength and tracking alignment requires care. Designs are well-documented in cycling literature and can be adapted to available materials.

Capacity. A well-built bicycle trailer can carry 50–150 kg depending on frame strength, wheel size, and road conditions.²⁹ For most community transport needs — grocery runs, tool transport, light freight — 50–80 kg capacity is adequate.

Materials required per trailer:

Component	Material	NZ source
Frame	Mild steel tube, 3–5m	NZ Steel (Doc #89) via distributors
Bed	Plywood or sheet steel	NZ timber/plywood industry; NZ Steel
Wheels (2)	Salvaged 20” bicycle wheels	From children’s bikes or purpose-built
Axle	Steel rod, 10mm diameter	NZ Steel or salvage
Hitch	Steel plate and bolt assembly	Fabricated
Tires and tubes (2)	Salvaged or from stock	National tire reserve

6.3 Cargo bicycles

Cargo bikes are purpose-built bicycles with integrated cargo platforms — either front-loading (bakfiets/box bike style), long-tail (extended rear frame), or utility-frame designs. These are more capable than standard bike + trailer combinations but harder to fabricate.

Front-loading (bakfiets) style. A box or platform between the handlebars and front wheel, steered via linkage. Capacity: 80–200 kg including the box. Excellent for child transport, grocery delivery, and bulky items. Fabrication requires more complex frame geometry and steering linkage — achievable for skilled fabricators but not a quick workshop project. Estimated fabrication time: 40–80 person-hours per bike.³⁰

Long-tail style. An extended rear frame with a larger rear rack. Simpler to fabricate than bakfiets — essentially a standard bicycle frame with a longer rear triangle. Capacity: 60–120 kg on the extended rack. Can carry two children on the rear, or large panniers. Estimated fabrication time: 20–40 person-hours.

Conversion of existing bikes. Standard bicycles can be partially converted to cargo roles by fitting stronger racks (fabricated from steel rod or tube), larger panniers (fabricated from plywood or canvas), and lower gearing. This is the quickest path to increased cargo capacity and should be the first step — before purpose-building cargo bikes.

6.4 Rickshaws and pedicabs

For passenger transport — particularly for elderly or disabled individuals who cannot cycle — bicycle-powered rickshaws or pedicabs provide a practical solution. These can be fabricated from bicycle components and steel tube. A three-wheeled pedicab with a rear passenger bench can carry 1–2 adult passengers over flat to moderate terrain.

Historical and contemporary precedent. Bicycle rickshaws remain a significant transport mode in cities across South and Southeast Asia, with an estimated several million in operation across India, Bangladesh, and Indonesia.³¹ NZ fabrication from local materials is achievable for a skilled welder-fabricator, though the three-wheeled geometry requires more careful alignment than a standard bicycle frame. The main ongoing maintenance challenge is bearing wear in the rear axle, which carries the full load of passengers plus the vehicle weight.³²

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7. BICYCLE FRAME MANUFACTURING FROM NZ STEEL

7.1 What a bicycle frame requires

A bicycle frame is a structure of welded or brazed steel tubes, designed to support a rider (and cargo) while providing steering geometry, pedaling position, and mount points for wheels, brakes, and drivetrain.

Material: Bicycle frames are traditionally made from chromoly steel (4130 — chrome-molybdenum alloy steel) or plain carbon steel (1020 or similar). Chromoly is lighter and stronger for the same wall thickness, but plain carbon steel is perfectly functional — it results in a heavier frame (approximately 2–3 kg versus 1.5–2 kg for the frame alone), but this weight penalty is minor for utility cycling.³³

NZ Steel capability. Glenbrook produces carbon steel (Doc #89). It does not produce seamless tubing — its product range is flat-rolled steel (coil, plate, sheet) with some downstream products. Converting flat steel to tubing requires:

• Tube rolling: Flat strip is formed into tube shape and welded (ERW — electric resistance welded). NZ has some tube-making capability — several NZ companies produce steel tube for structural, fencing, and industrial applications from NZ Steel coil.
• Drawn tubing: For lighter, higher-quality bicycle tubing, rolled tube is cold-drawn through a die to reduce wall thickness, improve surface finish, and increase strength through work-hardening. NZ has limited or no cold tube-drawing capability for the thin-wall tubing used in bicycle frames (0.5–1.2mm wall thickness).³⁴

Realistic assessment. NZ can produce bicycle frames from locally made ERW steel tube in the 1.2–2.0mm wall thickness range. These frames will be heavier than imported frames (perhaps 3–5 kg versus 1.5–2.5 kg for a frame) but entirely functional for utility cycling. The tubes will not be butted (varying wall thickness for strength optimization), which is a weight penalty but not a functional limitation.

7.2 Frame fabrication

Frame building requires:

• Tube cutting and mitering: Cutting tubes to length and shaping the ends to fit together at the correct angles. This requires a tube notcher or a grinder and templates. Angles and dimensions must be correct to produce a rideable bicycle — steering geometry (head tube angle, fork rake) particularly affects handling.³⁵
• Jigging: A frame jig holds tubes in correct alignment during welding or brazing. A purpose-built bicycle frame jig is not essential — a flat table with clamps and angle fixtures can serve, though alignment accuracy will be lower.
• Joining: TIG welding is the standard modern method for steel bicycle frames. MIG welding is also possible with appropriate technique. Silver brazing with lugs (traditional method) produces excellent results but requires lugs (tube junction sleeves) that would need to be fabricated or cast. NZ welders are numerous and skilled — welding a bicycle frame is well within the capability of any competent fabricator, though producing consistent geometry across many frames requires practice and process discipline.
• Heat treatment and finishing: Welded frames should be stress-relieved (heated to approximately 580–640°C and slow-cooled) to reduce residual stresses from welding.³⁶ This is standard workshop practice. Finishing (paint, powder coat, or rust-proofing) protects against NZ’s damp climate.

7.3 Forks

The front fork is the most stressed bicycle component — it handles braking forces, road impacts, and steering loads. A welded steel fork from NZ-produced tube is feasible but the steerer tube (which fits into the head tube bearings) requires accurate machining to fit standard headset bearing races. Purpose-built fork tooling simplifies this.

7.4 Wheels

Bicycle wheels consist of a hub, spokes, nipples, rim, tire, and tube. Of these:

• Rims can be formed from extruded aluminum (if Tiwai Point smelter continues operating — uncertain; the smelter depends on Manapouri hydroelectric supply and imported alumina from Australia) or rolled steel.³⁷ Steel rims are heavier (approximately 300–500g more per rim than aluminum) but perfectly functional and were standard on bicycles for decades before the aluminum transition.
• Spokes are drawn steel wire, typically 14-gauge (2.0mm) or 15-gauge (1.8mm), with a 90-degree bend and head at one end and threading at the other. NZ wire drawing capability (Doc #105) can produce spoke wire. Threading requires a threading die — standard workshop equipment.
• Nipples are small brass or steel nuts that tension the spokes. These are tiny precision parts — mass production requires screw machines or CNC lathes. Hand production is tedious but possible.
• Hubs — see Section 4.3 on bearings. Cup-and-cone hubs can be turned on a lathe. The critical dimensions are the bearing surfaces and the axle.

7.5 Production timeline and scale

Phase 2 (years 1–3): Prototype frames from existing NZ tube stock. Small production runs (tens of frames) at engineering workshops with welding capability. Quality variable — learning curve for frame geometry and alignment.

Phase 3 (years 3–7): Establish dedicated frame production at 1–3 workshops. Target: 500–2,000 frames per year. Use NZ Steel tube processed through existing NZ tube mills. Develop wheel building and spoke production.

Phase 4 (years 7–15): Scale production. Target: 5,000–20,000 complete bicycles per year, integrating NZ-produced frames, wheels, and (by this point) chains, sprockets, and bearings. Tires remain the binding constraint unless rubber trade or local alternatives have materialized.

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8. ROAD AND INFRASTRUCTURE ADAPTATION

8.1 Bike lanes become infrastructure, not amenity

In pre-event NZ, cycle lanes were a contested urban amenity — politically contentious, resisted by motorists, justified on health and environmental grounds. Under recovery conditions, cycle lanes are essential transport infrastructure, no different in kind from road shoulders or rail lines. The political calculus reverses entirely: allocating road space to bicycles is no longer a lifestyle choice but a transport efficiency decision.

8.2 Implementation

Separated lanes on major urban routes. Physical separation (concrete planters, timber barriers, painted kerb extensions) on arterial roads in cities with significant cycling volumes. This can be implemented with modest materials and labour — no major construction required, primarily repositioning of existing barriers and application of paint.³⁸

Reduced speed limits. Already recommended for tire and fuel conservation (Doc #33, Doc #53). Speed limits of 30 km/h urban and 60 km/h open road make roads dramatically safer for mixed bicycle/vehicle traffic. At 30 km/h, a vehicle-bicycle collision is survivable; at 50 km/h, it frequently is not.³⁹

Secure bicycle parking. At workplaces, shops, community centres, schools, transport hubs. Does not require elaborate infrastructure — a steel rail or fence loop to which a bicycle can be locked is sufficient. The main requirement is coverage from rain (important in NZ’s wet climate) and visibility for security.

Bicycle-priority intersections. Traffic signal timing and intersection geometry that prioritizes bicycle throughput over vehicle throughput in urban areas. Simple changes: advanced stop boxes (painted areas where cyclists wait ahead of vehicles), bicycle-specific signal phases, and protected turning movements.

Surface maintenance. Bicycle tires are more vulnerable to potholes, broken glass, and loose gravel than car tires. Maintaining smooth surfaces on primary cycling routes is a direct investment in transport capacity (fewer punctures, fewer crashes, faster travel). This does not require new road construction — it requires targeted pothole repair and sweeping.

8.3 Intermodal integration

Bike-to-rail. NZ’s rail network connects major cities (Auckland–Hamilton–Wellington on the North Island Main Trunk; Christchurch–Dunedin–Invercargill in the South Island; TranzAlpine Christchurch–Greymouth). If rail services are maintained or expanded (rail is electric in some sections and can be expanded using NZ’s grid), bicycle-rail integration — carrying a bicycle on the train and cycling at both ends — extends the practical range of bicycle transport enormously. A cyclist can ride 10 km to a rail station, travel 200 km by train, and ride 10 km at the destination. This requires designated bicycle storage on trains (or in simple bicycle carriages) and secure parking at stations.

Bike-to-ferry. NZ’s geography — two main islands, numerous harbours — makes ferry transport important. The Cook Strait ferry (Wellington–Picton) and harbour ferries (Auckland, Wellington) are natural integration points. Bicycles are already carried on NZ ferries; the infrastructure exists and requires only scaling.

Bike-to-bus. Urban and regional buses can carry bicycles on front-mounted racks (already common on NZ buses) or in underfloor storage. Bus routes that serve as feeders to rail or ferry connections create an integrated public transport network that the bicycle extends at each end.

Marae as staging points. NZ has over 900 active marae, spaced roughly 10–30 km apart in populated areas — a distance that matches practical daily cycling range.⁴⁰ This makes marae natural rest and freight transfer points for bicycle-based transport networks. Their existing physical infrastructure (kitchens, sleeping quarters, covered areas) supports overnight stops and load staging. Marae-based repair workshops extend the maintenance network to serve both local communities and passing cyclists, consistent with manaakitanga (hospitality).

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9. HISTORICAL PRECEDENT

9.1 Wartime bicycle transport

Bicycles have served as critical transport infrastructure in multiple conflict and scarcity contexts:

WWII — Occupied Europe. In the Netherlands, Denmark, and other occupied countries, bicycles became primary transport as fuel was requisitioned and vehicle use restricted. The Netherlands — already a cycling culture — relied almost entirely on bicycles for personal transport throughout the occupation. The post-war Dutch cycling infrastructure that exists today has its roots in this wartime necessity.⁴¹

Vietnam — the Ho Chi Minh Trail. North Vietnamese logistics used modified bicycles to transport supplies along the Ho Chi Minh Trail. Reinforced frames with extended cargo racks could carry 150–200 kg of supplies, pushed rather than ridden on steep terrain. Each bicycle replaced roughly one porter’s load and could be operated by a single person. Tens of thousands of tonnes of supplies were moved by bicycle during the conflict.⁴²

China — 20th century. China’s bicycle fleet peaked at an estimated 500 million in the 1980s and 1990s, providing the majority of urban personal transport before the automobile transition. Chinese bicycle infrastructure — separated lanes, bicycle parking, repair culture — demonstrates that bicycle-based urban transport works at continental scale.⁴³

Cuba — Special Period (1990s). When Soviet oil subsidies ended, Cuba imported over a million Chinese bicycles and developed domestic bicycle transport infrastructure as fuel became unavailable for most personal transport. The Cuban experience is particularly relevant to NZ’s scenario: a small nation cut off from fuel imports, with an educated population and functioning government, adapting to transport austerity.⁴⁴

9.2 Lessons for NZ

The historical precedents are consistent: when fuel becomes scarce, bicycles become primary transport, not by choice but by necessity. The transition is fastest and least disruptive in societies that already have cycling culture and infrastructure (the Netherlands), and slowest in societies that were entirely car-dependent (no good historical parallel exists for a fully car-dependent society losing fuel permanently — NZ would be a first). NZ sits somewhere in between: cycling exists as recreation and sport, some urban cycling infrastructure exists (Christchurch, some Auckland and Wellington routes), and NZ’s temperate climate is generally suitable for year-round cycling. But NZ lacks the flat terrain and cycling normalisation of the Netherlands.

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10. CRITICAL UNCERTAINTIES

Uncertainty	Why it matters	How to resolve
Actual bicycle stock (number, type, condition)	Determines immediate cycling transport capacity	National asset census (Doc #8)
Bicycle tire and tube stocks in distribution chain	Determines how long pneumatic tires last	Retail and wholesale inventory as part of requisition
E-bike battery condition and remaining life	Determines duration of electric-assist capability on hills	E-bike inventory with battery health testing
NZ Steel tube suitability for bicycle frames	Determines feasibility and timeline of local frame production	Engineering assessment with NZ tube mills
Chain manufacturing precision achievable from NZ workshops	Chain is the hardest component to produce locally	Prototype program (Doc #91 machine shops)
Bearing production quality	Bearings are the second-hardest component	Machine shop trials
Crumb rubber solid tire feasibility	Long-term tire substitute	Experimental program (coordinated with Doc #33)
Public cycling competence and willingness	Many NZ adults have not cycled regularly since childhood	Training programs, early assessment
Terrain suitability mapping	Which routes and towns can viably shift to cycling	Gradient survey of urban and rural routes

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CROSS-REFERENCES

Document	Relationship
Doc #6 — Vehicle and Transport Asset Management	Parent document; strategic transport framework including bicycle section
Doc #33 — Tires	Rubber dependency shared with bicycle tires; tire management and alternatives
Doc #34 — Lubricant Production	Bio-lubricants for bicycle chain and bearing maintenance
Doc #35 — Battery Management	E-bike battery supply, lead-acid production for e-bike conversion
Doc #53 — Fuel Allocation	Fuel rationing drives modal shift to cycling
Doc #56 — Wood Gasification	Alternative fuel for vehicles; bicycle fills the personal transport gap
Doc #89 — NZ Steel: Glenbrook	Steel tube supply for frame and trailer manufacturing
Doc #91 — Machine Shop Operations	Fabrication capability for bicycle components, chain production
Doc #105 — Wire Drawing and Spring Making	Spoke wire and chain component production
Doc #160 — Heritage Skills Preservation	Wheelwrighting and other relevant traditional skills
Doc #156 — Skills Census	Establishes actual bicycle stock and mechanic workforce

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APPENDIX A: COMMUNITY BICYCLE WORKSHOP — MINIMUM EQUIPMENT LIST

A functional community bicycle workshop requires the following tools and materials. Most of these are available from NZ bicycle shops, hardware stores, and engineering suppliers. They should be secured early through the consumables requisition process.

Essential tools:

• Floor pump with pressure gauge (1–2 per workshop)
• Patch kit supplies (patches, sandpaper, cement — or heat vulcanizer)
• Tire levers (multiple sets)
• Allen key set (metric: 2mm–10mm)
• Open-end wrenches (8mm–17mm)
• Cone wrenches (13mm–17mm)
• Chain tool (for breaking and rejoining chains)
• Chain wear gauge
• Spoke wrench (nipple wrench)
• Cable cutters
• Third-hand tool (brake spring compressor)
• Crank puller
• Bottom bracket tools (varies by type)
• Headset press (can be improvised from threaded rod and washers)
• Wheel truing stand (can be improvised from a frame fork and zip ties)
• Workstand (holds bicycle for repair — can be fabricated from steel tube)

Consumables:

• Inner tubes (assorted sizes: 26”, 27.5”, 29”, 700c)
• Brake pads (rim and disc)
• Cables and housing (brake and shift)
• Chain links and master links
• Lubricant (petroleum while available; lanolin/tallow thereafter)
• Grease
• Bearing balls (assorted sizes)
• Spokes (assorted lengths and gauges)
• Spoke nipples
• Rim tape
• Handlebar tape/grips

Workshop space: A covered, well-lit area of approximately 20–40 m2 with a workbench, tool storage, and enough room for 2–3 bicycles under simultaneous repair. A garage, shed, or dedicated room in a community building suffices.

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APPENDIX B: BICYCLE MECHANIC TRAINING CURRICULUM (SUMMARY)

Level 1 — Basic Maintenance (2–4 days)

• Puncture repair (tube removal, patching, reinstallation)
• Tire replacement
• Brake adjustment (rim brakes)
• Chain lubrication and cleaning
• Basic gear adjustment (limit screws, cable tension)
• Wheel quick-release and axle nut operation
• Safety check (brakes, tire condition, steering, wheel true)

Level 2 — Intermediate Repair (2–4 weeks)

• Wheel truing (spoke tension adjustment)
• Hub overhaul (cup-and-cone bearing service)
• Bottom bracket overhaul
• Headset adjustment and overhaul
• Cable and housing replacement
• Chain replacement and drivetrain assessment
• Brake system overhaul
• Frame assessment (crack identification, alignment check)

Level 3 — Advanced Workshop (3–6 months)

• Wheel building from components
• Frame repair (cold-setting, dropout alignment, minor crack welding)
• Component modification and fabrication
• Cargo bike and trailer design and construction
• E-bike electrical system diagnosis and repair
• Teaching and workshop management

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1. Bicycle power requirements: well-established in exercise physiology and cycling engineering literature. A typical rider on flat ground at 15–20 km/h requires 25–75 watts depending on rider weight, bicycle type, wind, and road surface. See: Wilson, D.G., “Bicycling Science,” MIT Press, 3rd edition, 2004. The 2,000–5,000 watt figure for a car at the same speed reflects total drivetrain power required to overcome rolling resistance, aerodynamic drag, and drivetrain losses at 15–20 km/h — mostly rolling resistance at such low speeds.↩︎

2. Bicycle tire weight and lifespan: typical road tire 200–350g, mountain bike tire 500–900g, touring/commuter tire 400–700g. Lifespan varies enormously with tire compound, surface, load, and inflation. 3,000–10,000 km is a typical range for commuter and touring tires. Car tire comparison at 8–12 kg per tire, 40,000–80,000 km lifespan. Per-km rubber consumption ratio derived from these figures.↩︎

3. Vehicle part count comparison: a modern car has approximately 30,000 individual parts (Toyota manufacturing data, frequently cited). A bicycle has approximately 200–300 parts depending on granularity of counting. The comparison illustrates maintenance complexity.↩︎

4. NZ bicycle import and stock estimates: NZ imports approximately 300,000–400,000 bicycles per year based on Stats NZ trade data. Standing stock estimate assumes 8–12 year average functional life with significant attrition to disuse. The figure of 1.5–2.5 million is an order-of-magnitude estimate that requires verification through the national asset census. See also Doc #6 Section 7.2.↩︎

5. Door-to-door travel time comparison for short urban trips is well-established in transport planning literature. For trips under 5 km, cycling is often faster door-to-door than driving when parking time is included. See: Pucher, J. and Buehler, R., “City Cycling,” MIT Press, 2012.↩︎

6. Metabolic cost of cycling: approximately 400–600 kcal/hour for moderate-intensity cycling (15–20 km/h), of which approximately 300–400 kcal is above resting metabolism. Source: standard exercise physiology references; also McArdle, W.D., Katch, F.I., and Katch, V.L., “Exercise Physiology: Nutrition, Energy, and Human Performance,” various editions.↩︎

7. Diesel consumption for light truck at 10 km loaded trips: assumes fuel consumption of 15–25 liters/100 km for a loaded light truck operating at low speed with frequent stops. Actual consumption depends heavily on vehicle type, load, terrain, and driving pattern.↩︎

8. Workshop setup estimate based on similar community tool library and repair workshop projects. The 40–80 person-hour range covers space preparation, tool organization, initial volunteer training, and first operational day. Ongoing operation requires 10–20 volunteer-hours per week for a community of 2,000–5,000 people.↩︎

9. NZ pre-event daily petroleum consumption of approximately 23–25 million liters per day (Doc #53). The 750,000 liters/day saving from 500,000 bicycles displacing 7.5M vehicle-km at 10L/100km is approximately 3% of this figure. The more important saving is in tires and vehicle parts, not fuel (since fuel rationing already reduces most vehicle use).↩︎

10. NZ bicycle import and stock estimates: NZ imports approximately 300,000–400,000 bicycles per year based on Stats NZ trade data. Standing stock estimate assumes 8–12 year average functional life with significant attrition to disuse. The figure of 1.5–2.5 million is an order-of-magnitude estimate that requires verification through the national asset census. See also Doc #6 Section 7.2.↩︎

11. NZ bicycle type distribution is estimated based on import data categories and cycling participation surveys. Mountain bikes dominate NZ imports due to the country’s strong mountain biking culture and trail network. Exact distribution would be established through the asset census.↩︎

12. Christchurch cycling culture: Christchurch has historically had NZ’s highest cycling mode share for commuting, at approximately 7% prior to the 2010–2011 earthquakes, compared to approximately 1–3% nationally. Post-earthquake cycling rates recovered and in some areas exceeded pre-earthquake levels due to new cycling infrastructure. Source: Christchurch City Council cycling data; NZ Census transport data.↩︎

13. Power requirements for hill climbing: the power to climb a grade at constant speed is approximately P = (mass × gravity × speed × grade) + (rolling resistance power) + (aerodynamic power). For a 90 kg system (75 kg rider + 15 kg bike/load) on a 10% grade at 8 km/h: climbing power = 90 × 9.81 × 2.22 m/s × 0.10 ≈ 196 watts, plus rolling resistance of approximately 15 watts, for a total of approximately 210 watts. This is sustainable for a fit adult but demanding for an untrained or elderly rider.↩︎

14. Gear ratio modification: fitting a larger rear sprocket (e.g., replacing a 34-tooth with a 36- or 40-tooth cassette sprocket) requires confirming derailleur capacity, chain length, and hanger compatibility. The procedure is standard bicycle shop work described in Park Tool and Shimano dealer manuals. Time estimate of 1–2 hours includes rear wheel removal, cassette swap, chain sizing, and derailleur limit adjustment.↩︎

15. Bicycle tire weight and lifespan: typical road tire 200–350g, mountain bike tire 500–900g, touring/commuter tire 400–700g. Lifespan varies enormously with tire compound, surface, load, and inflation. 3,000–10,000 km is a typical range for commuter and touring tires. Car tire comparison at 8–12 kg per tire, 40,000–80,000 km lifespan. Per-km rubber consumption ratio derived from these figures.↩︎

16. NZ bicycle tire import estimate: NZ imports approximately 300,000–400,000 bicycles per year, each with 2 tires. Replacement tire imports add an estimated 100,000–200,000 per year based on typical replacement rates. Total annual tire import: approximately 400,000–600,000. In-country stock estimate based on 2–4 months of normal supply in the distribution chain. These figures are estimates requiring verification from Stats NZ trade data.↩︎

17. Solid bicycle tire performance: solid rubber and foam-filled tires are commercially available (marketed as puncture-proof). User experience data consistently reports significantly harsher ride quality, higher rolling resistance (approximately 30–50% higher power required at the same speed), and increased rider fatigue compared to pneumatic tires. These penalties are the direct result of the tire’s inability to deform and absorb road imperfections.↩︎

18. Airless tire insert performance: commercially available foam and lattice inserts (e.g., Tannus, Rhinotire) report rolling resistance approximately 15–30% higher than equivalent pneumatic tires in independent testing, with significantly reduced vibration damping. The performance improvement over fully solid tires comes from the insert’s ability to compress partially under load. Source: manufacturer technical data and independent cycling forum testing reports. Performance of locally fabricated foam inserts would likely be worse than commercial products.↩︎

19. Pre-pneumatic bicycle tires: John Boyd Dunlop patented the pneumatic bicycle tire in 1888. Prior to this, bicycles (penny-farthings and early safety bicycles) used solid rubber tires bonded to metal rims, or in earlier designs, bare metal or leather-wrapped rims. Source: Herlihy, D.V., “Bicycle: The History,” Yale University Press, 2004.↩︎

20. Bicycle chain construction: a standard 1/2” pitch bicycle chain consists of alternating inner and outer link pairs. Each outer link pair has 2 outer plates and 1 pin (rivet). Each inner link pair has 2 inner plates and 1 roller (in bushed chains) or direct pin contact (in bushless chains). A 116-link chain has 58 inner links and 58 outer links, requiring 232 plates, 116 pins, and (in bushed designs) 116 rollers — over 460 individual parts plus the master link. Reference: Sheldon Brown, “Chains,” sheldonbrown.com (widely cited bicycle technical reference).↩︎

21. Chain wear measurement and replacement thresholds: 0.5% elongation is a common replacement threshold for multi-speed drivetrains; 0.75% for single-speed. Beyond 1.0%, sprocket damage is rapid. Source: Park Tool chain checker documentation; Shimano and SRAM technical guides.↩︎

22. Bearing ball production: precision bearing balls require high sphericity (typically ±0.0001” for bicycle bearings) and high surface hardness (Rockwell C 60–65). Local machine shop production using hardened steel rod turned on a lathe and polished can achieve serviceable but inferior sphericity and hardness — resulting in higher friction and shorter bearing life. The performance gap compared to commercial bearings is significant but the bearings will function.↩︎

23. Tallow-based bicycle grease: calcium grease produced from tallow and lime (calcium hydroxide) is described in Doc #34. For bicycle bearing applications, the main limitations are: lower dropping point (approximately 80–90°C versus 120–150°C for lithium grease), poorer water resistance (washes out in wet conditions), and lower oxidative stability (requires more frequent repacking). Adding lanolin (available from NZ wool processing) improves water resistance. Repacking frequency of 1,000–2,000 km versus 5,000–10,000 km is an estimate based on the known performance characteristics of calcium greases in wet environments.↩︎

24. NZ e-bike estimates: e-bike sales have grown rapidly in NZ, with estimated annual sales of 20,000–40,000 units in recent years. The cumulative fleet estimate of 60,000–120,000 accounts for growth in sales over the past 5–7 years with some attrition. Exact figures are not published by Stats NZ in a separate e-bike category; this estimate draws on industry reports and import data for electrically assisted cycles.↩︎

25. E-bike charging energy: a typical 500 Wh e-bike battery requires approximately 0.5–0.6 kWh to charge from empty (accounting for charger efficiency losses). An electric kettle rated at 2,000–2,400 watts consumes approximately 0.5–0.6 kWh in 12–18 minutes of continuous operation — comparable to a single full e-bike charge. NZ’s grid electricity is predominantly renewable (approximately 85% hydro, geothermal, and wind). Source: MBIE NZ energy data, https://www.mbie.govt.nz/building-and-energy/energy-and-n...↩︎

26. E-bike battery degradation: lithium-ion batteries lose capacity through both cycling (charge-discharge) and calendar aging. Most manufacturers rate batteries for 500–1,000 full charge cycles to 70–80% of original capacity. Calendar aging reduces capacity by roughly 2–3% per year even without use. Under daily cycling use (one full charge per day), 500 cycles represents approximately 1.5–2 years; 1,000 cycles represents approximately 3 years. Practical usable life depends on acceptable capacity threshold. Source: general lithium-ion battery literature; see also Doc #35.↩︎

27. Lead-acid versus lithium-ion energy density: lithium-ion e-bike batteries achieve approximately 150–250 Wh/kg at the pack level. Lead-acid achieves approximately 30–40 Wh/kg at the pack level — roughly 5–6 times heavier for the same energy. A typical 500 Wh lithium pack weighs approximately 2.5–3.5 kg; a lead-acid equivalent would weigh approximately 12–18 kg. The additional weight reduces range and increases power requirements on hills, partially offset by the motor assist. Source: battery chemistry references; see Doc #35 for NZ lead-acid production pathway.↩︎

28. Bicycle trailer fabrication time: based on documented build times for DIY bicycle trailers in cycling and maker communities. Simple flat-bed trailer designs with two wheels typically require 8–16 hours for a competent welder including material preparation, welding, finishing, and wheel attachment. More complex designs (folding, suspension, enclosed) take longer.↩︎

29. Bicycle trailer and cargo bike capacity: standard commercial bicycle trailers (e.g., Burley, BOB, Surly) are rated for 45–135 kg depending on design. Simple fabricated trailers can match or exceed these capacities depending on frame strength and wheel choice. Ratings are manufacturer limits; practical loads depend on road surface, gradient, and rider capability.↩︎

30. Cargo bike fabrication time: a front-loading bakfiets-style cargo bike requires significantly more complex frame geometry, steering linkage, and structural engineering than a standard bicycle. The 40–80 person-hour estimate includes frame fabrication, steering linkage, cargo box/platform, and assembly, but not component sourcing or painting. Based on documented small-workshop cargo bike builds.↩︎

31. Bicycle rickshaws: estimates of rickshaw fleets vary widely. Dhaka, Bangladesh alone has an estimated 400,000–800,000 cycle rickshaws; Indian cities collectively have several million. The design — a reinforced frame with a rear passenger platform on two wheels and a single front driving wheel — has been refined over more than a century. Source: Gallagher, R., “The Rickshaws of Bangladesh,” University Press, 1992; also Replogle, M., “Non-Motorized Vehicles in Asian Cities,” World Bank Technical Paper, 1992.↩︎

32. Bicycle rickshaws: estimates of rickshaw fleets vary widely. Dhaka, Bangladesh alone has an estimated 400,000–800,000 cycle rickshaws; Indian cities collectively have several million. The design — a reinforced frame with a rear passenger platform on two wheels and a single front driving wheel — has been refined over more than a century. Source: Gallagher, R., “The Rickshaws of Bangladesh,” University Press, 1992; also Replogle, M., “Non-Motorized Vehicles in Asian Cities,” World Bank Technical Paper, 1992.↩︎

33. Bicycle frame materials: 4130 chromoly steel is the standard for quality steel frames (density 7.85 g/cm3, yield strength approximately 460 MPa). Plain carbon steel (1020, yield strength approximately 350 MPa) requires approximately 30% thicker walls for equivalent strength, resulting in a heavier frame. For utility cycling where frame weight is a minor concern relative to rider and cargo weight, the penalty is negligible. Reference: Paterek, T., “The Paterek Manual for Bicycle Framebuilders,” Framebuilders’ Cooperative, various editions.↩︎

34. NZ tube manufacturing capability: several NZ companies produce ERW (electric resistance welded) steel tube from NZ Steel coil, including Steel & Tube and other distributors/processors. These produce structural tube, fencing tube, and industrial tube. Thin-wall tubing suitable for bicycle frames (0.5–1.2mm wall, 25–38mm OD) may require specific rolling setups. NZ does not have documented cold tube-drawing capability for bicycle-grade butted tubing. This assessment requires verification with NZ tube manufacturers.↩︎

35. Bicycle frame geometry: head tube angle (typically 68–73° for utility bikes), seat tube angle (72–75°), chainstay length, bottom bracket drop, and fork rake collectively determine handling characteristics. Small errors in these dimensions can produce a bicycle that handles poorly or unsafely. Frame builders develop consistency through jig design and experience. Reference: Rinard, D., various bicycle engineering publications and framebuilding technical references.↩︎

36. Stress relief heat treatment for welded steel bicycle frames: the recommended temperature range for stress relief of low-carbon steel weldments is approximately 580–650°C (1075–1200°F), held for approximately 1 hour per 25mm of thickness, followed by slow cooling (furnace cool or insulated cool). Source: ASM International, “ASM Handbook, Volume 6: Welding, Brazing, and Soldering,” and standard welding engineering references.↩︎

37. Tiwai Point aluminium smelter: NZ’s only aluminium smelter, operated by New Zealand Aluminium Smelters (NZAS), located at Tiwai Point near Bluff. Produces approximately 330,000 tonnes of aluminium per year, powered primarily by the Manapouri hydroelectric station. The smelter processes imported alumina (from Australia) — NZ has no domestic bauxite deposits. If alumina imports cease, the smelter cannot operate regardless of electricity supply. Source: NZAS operational data; MBIE energy and resources publications.↩︎

38. Rapid cycling infrastructure implementation: the “tactical urbanism” approach to cycling infrastructure — using paint, planters, and movable barriers rather than permanent construction — has been demonstrated in numerous cities worldwide and in NZ (Christchurch post-earthquake cycling infrastructure used this approach extensively). Implementation time for a typical arterial cycle lane is days to weeks, not months.↩︎

39. Speed and collision survivability: the relationship between vehicle speed and pedestrian/cyclist fatality risk is well-established. At 30 km/h impact speed, pedestrian fatality risk is approximately 10%; at 50 km/h, approximately 40–80% depending on the study. Source: Rosén, E. and Sander, U., “Pedestrian fatality risk as a function of car impact speed,” Accident Analysis & Prevention, 2009.↩︎

40. Marae as logistics infrastructure: marae are community gathering places distributed across NZ, with an estimated 900+ active marae nationally. Their physical infrastructure (wharenui/meeting house, wharekai/dining hall, kitchen facilities, ablutions) and social infrastructure (kaumātua/elders, rūnanga/councils, established governance) make them functional logistics nodes. The spacing of marae in populated areas — typically 10–30 km apart — corresponds well with practical daily cycling distances. See also Doc #6 Section 8 for broader discussion of marae as logistics hubs.↩︎

41. Netherlands wartime cycling: during the German occupation (1940–1945), bicycles were the primary personal transport mode in the Netherlands. The occupying forces requisitioned many bicycles late in the war, and the phrase “give me my bicycle back” (geef me mijn fiets terug) became a cultural touchstone. Post-war Dutch cycling culture and infrastructure are directly rooted in wartime transport patterns. Source: Jordan, P., “In the City of Bikes: The Story of the Amsterdam Cyclist,” Harper Perennial, 2013.↩︎

42. Ho Chi Minh Trail bicycle logistics: North Vietnamese forces modified standard bicycles to carry loads of 150–200+ kg, pushed by a handler on steep terrain. The modified bicycles used reinforced frames, extended cargo racks, and bamboo push-handles. An estimated 100,000+ bicycles were used over the course of the conflict. Source: Prados, J., “The Blood Road: The Ho Chi Minh Trail and the Vietnam War,” Wiley, 1999.↩︎

43. China’s bicycle fleet: estimates of China’s bicycle fleet peaked at approximately 500 million in the late 1980s to early 1990s, making bicycles the dominant urban transport mode. The subsequent automobile transition has reduced cycling’s modal share dramatically. Source: Hook, W. and Replogle, M., “Motorization and Non-Motorized Transport in Asia,” Land Use Policy, 1996.↩︎

44. Cuba’s Special Period bicycle program: following the collapse of the Soviet Union and loss of oil subsidies, Cuba imported approximately 1.2 million bicycles from China in the early 1990s and developed bicycle repair infrastructure, designated bicycle lanes, and parking facilities. The program was partially successful but hampered by tropical heat, hilly terrain in some areas, and cultural resistance to cycling. Source: Enoch, M. and Warren, J., “Automobile use in less developed countries: Cuba as a case study,” Transportation Research Record, 2008.↩︎