>Andrew wrote:
>
>"Attempts to place a value or description on bike handling can be like trying
>to compare art work. We do it all the time but it doesn't really mean much."
>
>********
>
>I have to differ with Andrew on this. Assuming control for a few
>variables, like wheels, tires and stem-length, and assuming these
>variables are more-or-less standard for the kind of bike
>involved--that is, light racing wheels, 25-25mm tubular tires, and
>stem-length typical for a given frame size for a late-70s
>professional-level racing bike--I think you can easily make
>meaningful comparisons of how frames ride, assuming some reasonably
>precise descriptive language. Short, steep, high bikes (short stays
>and top-tube, steep angles, high bb shells) all have a pretty strong
>family resemblance in the way they ride, just as long, slack, low
>frames do.
A good test is riding a few bikes, and seeing whether you can predict the geometry based on the handling, before you measure anything on the bike. (Obviously, you don't look too closely at the fork offset and things until you've ridden the bikes.)
We do this all the time in our tests for Bicycle Quarterly - ride first, measure afterwards - and usually, we are able to predict the geometry quite accurately. Basically, a bike with a 72-to-73-degree head angle and around 50 mm trail feels subtly different from a bike with the same head angle, but only 40 mm trail (assuming the same tires, etc.).
In some cases, we get a surprise - like a Bilenky that felt like it had less trail than what we measured (and what Bilenky thought they had built). This usually leads to a new discovery or realization - in the Bilenky's case, the handlebars were higher than we usually ride, so there was less weight on the front, and thus less wheel flop than we associated with those geometry numbers.
It's even more fun when you can predict the tubeset based on the ride. People have often discounted this. However, our double-blind test of three bikes, one of which had different tubing wall thicknesses, has shown that "lively" frames or what we call "planing" can be actual, measurable differences in the frames, not just in the riders' imagination.
This is not to say that all such observations are real. People telling me that their frames are going soft seems less plausible...
Jan Heine
Editor
Bicycle Quarterly
2116 Western Ave.
Seattle WA 98121
http://www.vintagebicyclepress.com