I used to have an old 28" wheeled roadster that I used as a barcycle an d loved the larger wheels; the slack geometry and especially the rod actu ated brakes took some getting used to (but the pubs are uphill on the way home, so no real speed generated). On a road bike, the proportions would l ook better using a 28" wheel with a tall frame, but I think the physics m ajors among us may tell us why things like gyroscopic forces or whatever, m ake it a less than ideal wheel dimension for the road. With mountainbikes h owever, the larger 29 inch wheel compared to standard 26" inch wheels are an incredible advancement for the large frame size. I'll never ride my 26e r again. See photo comparison here:http://theracingbicycle.com/Modern_Marve ls.html
If there are advantages with the larger wheel size for the road bike, rim manufacturers and tire manufacturers would still need to see a major mar ket for them to get production going, Don't really see that happening.
Meanwhile we can revel in these beautiful tall bikes of David Cooper's
http://www.coopertechnica.com/
Jay Van De Velde
Seal Beach,CA
From: paul grens <pgrens@yahoo.com> Subject: [CR] Wheelset built in proportion to large frame size To: classicrendezvous@bikelist.org Date: Thursday, March 12, 2009, 6:51 PM
Hey everyone,
I hope this hasn't been covered in the past (couldn't find anything in the archives) but something hit me the other day. I've got an early '80s Schwin n Voyageur S/P here that I'm tuning for a tall friend and it's got a 67cm s eat tube c-to-c. Not a bad tooling around town and lakefront path bike at a ll, but I can't help but notice how out of proportion the wheels seem to th e frame size.
Now, this is where my post is going to get hazy, as I don't know the proper engineering terms, but, for argument's sake, let's say the "ideal" seat tu be measurement on a frame in proportion to a build for a 700c wheelset wa s about 55 to 57cm c-to-c (sorry if I'm way off here, just seems like the standard as far as visual and handling balance goes with my limited ex perience), then this 67cm bike would then tend to ride top-heavy (it does)
and have a lower center of gravity (what I mean here is axle height in
relation to saddle height and rider weight positioning, and it does) and ha ve "squirrely" handling characteristics (I would say it does to an extent).
So, my question is this then, has anyone ever redesigned and built a road o r track frame with a larger wheelset to accommodate a larger rider's me asurements in a more proportional manner? Looking at page 16 in Tom Dough ty's "The Complete Book of Long-Distance Cycling and Competitive Cycling", you can see basketball star Bill Walton on a massive, custom-built track bi ke that certainly could have used a larger set of wheels to accommodate h is body's needs. I guess my thinking is, could you just proportionally in crease the size everything to get the same geometry, and has this ever been done?
Anyway, just a (long) thought.
Cheers,
Paul Grens
Chicago, Illinois, USA