It often has been asserted that fork rake, etc., don't make a difference in ride comfort. I believe that this is true with most current forks.
However, some of the super-skinny fork blades of old, combined with some generous rake, do seem to provide flex in the blade. Of course, I haven't measured it, but riding two Alex Singer, made of the same tubing, roughly the same geometry, but with different forks (same tires, etc., too), showed a distinct difference over the bumpy pavement of our city streets.
A disadvantage of the skinnier blades is the impossibility of doing track stand - the fork blades flex so much that the front wheel locks against one brake block (the Singer brakes don't self-center).
For an image of the Alex Singer with the skinny blades, see
http://www.mindspring.com/
Also, I used to think that forks deflect backwards when going over bumps. But Joe Breeze set me straight on that one, long ago. After all, supension forks (OT, I know) wouldn't work if that were the case...
Ernest Csuka, of Cycles Alex Singer, claims that a fork curved at the
bottom can deflect upward when hitting a bump, while a straight
(modern) fork can only deflect backwards, thus lifting the rider (and
causing discomfort). He may be wrong, but his bikes ride like no
others!
--
Jan Heine, Seattle
Editor/Publisher
Vintage Bicycle Quarterly
http://www.mindspring.com/
Phil & Todd,
You are right about bent vs. straight forks riding the same! (all else being equal, tubing etc.) And indeed, the bending moment does occur at the crown, not in the blades. I am glad you guys addressed this myth. I was biting my tongue about this one, also for fear of starting some sort of fork war. The truth is, straight blades are strictly a fashion/time/cost saving way to build forks.
Kirk Pacenti
Pacenti Cycle Design
http://www.bikelugs.com