BOM Strategy
Prototype 0 should spend effort on the parts that define Axlow: frame geometry, steering, seat structure, boom adjustment, chain management, braking layout, and visible product quality.
Standard bicycle parts should be bought out wherever possible. Custom gears, belt drive, suspension, folding, and electronics should remain future modules until the base vehicle is validated.
Fabricated Frame And Structure
| Item | Description | Qty | Source | Notes |
|---|
| F1 | Main spine tube, rectangular or round mild steel | 1 | In-house | Approx 1300-1500 mm final length after CAD |
| F2 | Front cross-member tube | 1 | In-house | Carries left/right steering assemblies |
| F3 | Rear fork/triangle tubes | 1 set | In-house | Supports rear driven wheel |
| F4 | Adjustable boom receiver tube | 1 | In-house | Welded into front of spine |
| F5 | Adjustable crank boom tube | 1 | In-house | Telescopes into receiver |
| F6 | Seat base support tubes | 1 set | In-house | Bolted or welded mounts |
| F7 | Seat back support tubes | 1 set | In-house | Prefer bolted angle adjustment |
| F8 | Front cross-member gussets | 2-4 | In-house | 3-5 mm MS plate |
| F9 | Seat mount brackets | 4-6 | In-house | Slotted or alternate holes for adjustment |
| F10 | Idler bracket | 1-2 | In-house | Machined or fabricated |
| F11 | Brake/cable tabs | As needed | In-house | Weld-on tabs |
| F12 | Light, reflector, and flag mounts | As needed | In-house | Visibility should be designed in early |
Steering And Controls
| Item | Description | Qty | Source | Notes |
|---|
| S1 | Left steering knuckle/upright | 1 | In-house or bought-out | High-risk design item |
| S2 | Right steering knuckle/upright | 1 | In-house or bought-out | Mirror of S1 |
| S3 | Kingpin shafts/bolts | 2 | In-house/bought-out | Must be robust and serviceable |
| S4 | Steering arms | 2 | In-house | Ackermann angle to be modeled |
| S5 | Tie rod | 1 | Bought-out/in-house | Threaded adjustment |
| S6 | Drag links/handle links | 2 | Bought-out/in-house | Depends on steering layout |
| S7 | Rod ends/heim joints | 4-8 | Bought-out | Prefer standard available parts |
| S8 | Side steering handles | 2 | In-house | Tube with bicycle grips |
| S9 | Mechanical steering stops | 2 | In-house | Prevent interference |
| S10 | Brake lever mounts | 1 set | In-house/bought-out | To be tested for rider reach |
Wheels, Tyres, And Brakes
| Item | Description | Qty | Source | Notes |
|---|
| W1 | 20 inch front wheel with disc hub | 2 | Bought-out | Left and right front |
| W2 | 26 inch rear wheel with cassette/freewheel hub | 1 | Bought-out | 20 inch rear alternate |
| W3 | Front tyres and tubes | 2 sets | Bought-out | 1.5-2.0 inch width for initial testing |
| W4 | Rear tyre and tube | 1 set | Bought-out | Match intended surface |
| B1 | Front mechanical disc calipers | 2 | Bought-out | Prototype baseline |
| B2 | Front brake rotors | 2 | Bought-out | Match hub and caliper selection |
| B3 | Brake levers | 1-2 | Bought-out | Linked vs independent to be tested |
| B4 | Brake cables and housing | 1 set | Bought-out | Route clear of steering movement |
| B5 | Rear parking brake | 1 | Optional | Useful for campus, senior, and parking use cases |
Drivetrain
| Item | Description | Qty | Source | Notes |
|---|
| D1 | Crankset | 1 | Bought-out | 1x or 3x after gearing review |
| D2 | Bottom bracket | 1 | Bought-out | Mounted in adjustable boom shell |
| D3 | Pedals | 1 pair | Bought-out | Standard bicycle pedals |
| D4 | Chain | 2-3 lengths | Bought-out | Long recumbent chain |
| D5 | Rear derailleur | 1 | Bought-out | For 1x8, 1x9, or 3x7 |
| D6 | Shifter | 1 | Bought-out | Handle placement to be decided |
| D7 | Cassette/freewheel | 1 | Bought-out | Wide range preferred |
| D8 | Power-side idler | 1 | Bought-out/in-house | Smooth, low-noise, robust |
| D9 | Return idler or guide | 1 | Optional | Depends on chain path |
| D10 | Chain tubes/guards | 1 set | Bought-out/in-house | Protect rider and clothing |
Seat, Finish, And Visibility
- Seat frame tubes fabricated in-house
- Breathable mesh or padded seat surface
- Edge trim for comfort and finish quality
- Bolted mount points with locking nuts and washers
- Standard bicycle grips
- Paint or powder coating after Prototype 0 geometry is validated
- Headlamp mount, rear lamp mount, brake lamp mount, side reflector mounts, and flag mount
- Optional headrest, cargo mount, and console mount reserved for future variants
Costing Buckets
- Frame material
- Cutting, bending, welding, and finishing labor
- Jigs and fixtures
- Steering custom parts
- Bought-out wheels, tyres, drivetrain, and brakes
- Seat material and fabrication
- Lighting and visibility hardware
- Assembly labor
- Testing, rework, and spare parts allowance
Later-Phase Parts
These should be tracked, but not allowed to delay Prototype 0.
- Electric assist motor, controller, battery, display, and wiring harness
- Compact ride console with speed, battery, mode, and navigation cues
- Internal gear hub, custom gearbox, or belt drive
- Front suspension or comfort suspension module
- Folding mechanism
- Cargo rack, utility tray, or campus/resort accessory pack