Originally Posted by
McBTC
The magic amount of trail is 57 and mechanical trail is the most meaningful so, with a head tube angle of 74° if you go with 28mm tires you're looking at a rake of 38.
Bicycle Trail Calculator | yojimg.net
Huh? I have two issues with this. The optimum trail varies (a little) by head angle. And, much bigger issue - different people have different tastes as to what "feels right". I have tracked the fork rake and head tube angles on the bikes I have owned. Yes, I am doing rake vs headset, not rake vs trail. Until quite recently I wasn't using big tires and all the bikes were ridden 700c so there was good correlation between the two and rake is easier to measure (and spec to a builder).
I have found all the bikes I really liked the handling of fell on a diagonal line on that rake/HS angle chart. Also that the corresponding trails also fell on a diagonal line when plotted trail vs HS angle. In other words, there is not one "magic" trail for me for all HS angles. Also the trail and "feel" I like is quite different from most published
"right" trails. When I order a new custom fork or whole frame, I will spec the rake. I always get questioned/corrected but I do not give the go-ahead to build until the builder sees it my way. (Second time around is much easier after the builder sees how much I like the fork he felt he built "wrong".)
Ben