Originally Posted by
jimmuller
Last year I threw together a Windows program to computer frame angles from length measurements. Indeed just playing around with small changes in length produces enough angle variation to show the sensitivity. You can download it here:
http://world.std.com/~muller/BikeFra...Calculator.zip
It's a fun toy (and accurate) but ultimately not very useful for that purpose.
I'd be more interested in your correlation between perceived handling and those measurements. I'd bet it isn't so cut and dry as it might first appear. If it is, then great.
Some of it I think is if you set the bike up as the frame builder suggests or if you are comparing, set up the seat at the same position and evaluate it from there.
Over time I have found that the 73° or 73.5° up to a 74° seat tube angle is probably best for me, but I can make even a bike with a 72.5° work pretty easily. This will get my saddle in the same spot on all.
From there getting the bars in about the same place can present a pretty wide range of stem extensions. This is with the same brand/style of handlebar. Having written all that... Bikes with a shorter front center, distance from the vertical line through the bottom bracket to the front axle can be more fun on the flats and need more attention on a descent. They are rewarding but demanding. These are for normal road bikes, save the Tesch S-22 which proclaims it is Built for Speed. The head angles vary and the rakes vary but the trail does not vary that much, no "low trail" machines in the bunch.
The bikes with lots of fork rake sometimes exhibit wheel flop, which shows itself on a local steep curvy 14% descent. Not my favorite feeling.