Tuesday, January 5, 2010

Front wheel drive

Quote from TOM TRAYLOR:

Over the years I have tried many different variations.

The way a bike handles depends on a lot of variables, but there are three that seem to effect handling more than anything else and they are: the steering head angle, the trail, and the rake.

I have found that a steering head angle of 62° to 65°, a trail of 4"- 4½", and a rake of 0 (zero) or even slightly negative, has worked very well for me. These numbers are not terribly critical with my bike design. Good handling to one person might be unacceptable to another. I have built bikes well outside these parameters and have had acceptable results.

Stay away from shallow steering head angles though.

My results are based on bikes with the bottom bracket at about the same height as the seat."

I think it is a mater of counter weight verses how hard you push on the pedals. Not very good for hill climbing, except with a motor.


This photo shows that it may be possible to build a front wheel drive bike without the over powering “pedal steer” that the Cruise bikes have too much of. The crank should be closer to a vertical line from the axle than the handle bars are. However it relies on counter weight, how much can you push with your leg? If the crank were located at the steering axis, then there would be virtually no side forces.

The Cruze bikes have more pedal steer than any other, all the force put into the pedals have to be pulled back at the handle bars, even a Flevo bike would be easier to ride. NOTE that none of these videos show any of these machines climbing hills. It would take a good low gear with fast crank spinning to climb hills on these.

Cruze bike vidio: http://www.youtube.com/watch?v=kBYUAV9QEws

The only kind of FWD that’s easy are the ones with the pedals not connected to the front forks.http://www.stitesdesign.com/

This one has no side forces because the crank is not on the front steering section.



Bicky said...

i climb hills with a flevobike.
and that what is with a low pedal speed

Prodromal said...

What gear ratio or gear inches do you use?

How steep are your worst hills?

And what weight?