B
B. Sanders
Guest
After some thought about aerodynamics vs. "streetability", I have modified the Speed Racer quite a
bit. It's still streetable; but it presents far fewer speed compromises, and yet retains steering
stability and minimal turning radius.
Here's a GIF image of the new design:
http://bsanders.net/SpeedRacer6.2.gif
Design highlights for this version:
- No rear suspension = maximum power transfer
- Extra-low seat height (lower than M5, Jester or Baron)
- M5-style fiberglass rigid seat
- Short wheelbase gives tighter turning radius
- Shallow head tube angle and plenty of trail
- Seat angle is steeper than the M5, Jester or Baron
- Non-power side chain routed to avoid leg interference
- Crank height is similar to M5 - lower than Jester, Baron
- Barnett Williams' chainstay design (1.5" pipe, brazed on)
- Avid mechanical disc brakes (V-brakes on test bike)
The steeper seat angle, shallow head angle, increased trail, minimal chain interference, disc brakes
and shorter wheelbase were all on my wish list after owning an M5 Low Racer. The 1.5" tubular steel
chainstays won't be quite as brutally rigid as the M5's massive sculptured steel stays; but should
be plenty efficient. This design (after it is tweaked a bit) could be as fast and stable as any bike
out there: Any speed deficiencies will be in the engine compartment, not from the bike design. I may
spec a monoblade instead of the BMX fork for later builds.
I think this one looks like a winner, and should be fairly easy to build. I'm going to have to
experiment a bit with the chain idlers quite a bit, it would seem; but the rest of it appears fairly
straightforward. Seat mounting should be a piece 'o cake.
Comments welcomed as always.
-Barry
bit. It's still streetable; but it presents far fewer speed compromises, and yet retains steering
stability and minimal turning radius.
Here's a GIF image of the new design:
http://bsanders.net/SpeedRacer6.2.gif
Design highlights for this version:
- No rear suspension = maximum power transfer
- Extra-low seat height (lower than M5, Jester or Baron)
- M5-style fiberglass rigid seat
- Short wheelbase gives tighter turning radius
- Shallow head tube angle and plenty of trail
- Seat angle is steeper than the M5, Jester or Baron
- Non-power side chain routed to avoid leg interference
- Crank height is similar to M5 - lower than Jester, Baron
- Barnett Williams' chainstay design (1.5" pipe, brazed on)
- Avid mechanical disc brakes (V-brakes on test bike)
The steeper seat angle, shallow head angle, increased trail, minimal chain interference, disc brakes
and shorter wheelbase were all on my wish list after owning an M5 Low Racer. The 1.5" tubular steel
chainstays won't be quite as brutally rigid as the M5's massive sculptured steel stays; but should
be plenty efficient. This design (after it is tweaked a bit) could be as fast and stable as any bike
out there: Any speed deficiencies will be in the engine compartment, not from the bike design. I may
spec a monoblade instead of the BMX fork for later builds.
I think this one looks like a winner, and should be fairly easy to build. I'm going to have to
experiment a bit with the chain idlers quite a bit, it would seem; but the rest of it appears fairly
straightforward. Seat mounting should be a piece 'o cake.
Comments welcomed as always.
-Barry