Jerry asks:
> Can any of the framebuilders tell me when
> the theory of "trail" and its effect on steering was
> developed or when it was first applied to bicycles?
Archibald Sharp covers the concept thoroughly in his 1896 book "Bicycles and
Tricycles"
> My point is, were framebuilders in the 60's and earlier
> even aware of trail, or did they just use the angles
> and fork rake that "worked" based on their experience?
Probably mostly the latter with a bit of the former. I doubt they read Sharp. Some dumb designs get re-invented every 10 years or so, though Sharp pointed out their flaws in 1896. Good, thoughtful designers could arrive at the idea of trail on their own though. Just look at a caster wheel, such as on a shopping cart - why do they always point in the right direction? Just like riding no-hands.
Mark Bulgier
Seattle, Wa USA