The Reid Alpha is shit (out of the box), buy something better. Anyhow, this is a ‘final’ list of modifications that I have made to my beach bike:
- 27.2 × 400 mm seat post (longer) and a more comfortable saddle.
- 70 mm x 22° stem (higher), bars trimmed to 640 mm and more comfortable grips.
- Front basket (carrying any loads at the front is better for weight distribution). I riveted mounting brackets to the forks.
- Quick release axle front hub and stainless spokes.
- Rear freehub and stainless spokes. To increase the rear chain line, I used a custom axle (currently a modified 3/8 inch threaded axle; high tensile M10 rod could be used) and cut a few millimetres off the 9 speed free hub (in hindsight, I could have simply added extra spacers behind the cassette).
- 9 speed groupset with a 8/9 speed hybrid cassette: 11-13-16-20-30-36-42 (the 11 and 13T sprockets are from a 9 speed cassette and the spacers are 9 speed). I purchased a wide-ratio 8 speed cassette (rather than removing one of the sprockets from a 9 speed cassette) because the gear steps are more uniform and the tooth profiles match (for smoother shifting). Only 8 sprockets are used to avoid the chain rubbing the rear tyre; if you want 9 or more speeds and a reasonably straight chain line then you need 190 mm wide dropouts (not this frame).
- 100 × 154 mm bottom bracket and frame trimmed (symmetrically) down to approximately 100 mm wide. This reduced the ‘tread’ (a.k.a. ‘Q-factor’) and the front chain line. Try different cranks before cutting the frame!
- 64-104 mm BCD cranks with a 26T chain ring and better pedals (the chain ring guard in the photo above is large because it is for 36T; that doesn’t bother me).
- I carry a piece of plywood for the kickstand.
The gearing is based on experience, including 50 km+ beach rides. Fat bikes have massive rolling resistance so forget about riding fast. I focus on conserving energy:
- 26 × 12T is useful on the road, with 20 psi in the tires; 26 × 11T is used occasionally.
- Around 26 x 20T is useful on hard sand and the chain line is straight (and efficient) in that gear.
- On soft sand, the first thing to do is ‘air down’ to approximately 10 psi. Then 26 × 36T can be used (with smooth pedaling) to ‘float’ on top of the soft sand. The chain does rub in first gear but 26 × 42T is rarely used.
- When tired and facing a headwind at high tide, I choose to walk.
Oval chain rings are more efficient; however small, oval chain rings are expensive.
Tubeless tyres reduce rolling resistance and increase efficiency, especially at low pressures; however I couldn’t get the bead to seal with these rims and/or tyres (that were not designed for tubeless).
