Re: [CR] Frame "stiffness"


Example: Production Builders:Peugeot

Date: Wed, 7 Jul 2010 19:26:48 -0700 (PDT)
From: EPL <lowiemanuel@yahoo.ca>
To: classicrendezvous@bikelist.org
Subject: Re: [CR] Frame "stiffness"


Interesting that the trend towards lighter gauge heat-treated steels in normal gauges (753, Prestige, etc.) came alongside the fashion for short wheelbase/short chainstay frames. Building frames with those tighter dimensions with .8/.5 or .9/.6 or 1.0/.7 gauge tubes might have resulted in harsh rides at all but the larger size frames, say, above 59cm c-c.

The option of thin-walled lighter-gauged normal diameter tubing which was still dent-resistant (a principal benefit of heat-treated pipes) made the tighter proportions more comfortable while also resuling in lighter weight frames (good for marketing!) that resisted denting.

I note that wise American frame makers like Brian Baylis and Richard Sachs et al have avoided short wheelbase/short chainstay designs. They also largely skipped tubing like 753. I can only assume they build their frames based on the primordial geometries of fit (because that's what counts most when you ride) not simple wall thickness/weight equations (a fool's game).

What happend with OS tubing is probably outside the CR definition of KOF frames. Who really needs OS tubing on a classic road bike, anyway?

There are many ways to save weight on a complete bike which do not compromise ride and durability the way light-gauged tubing may.

More important, a comfortable rider will pedal his machine longer and faster than an uncomfortable rider, never mind how light his steed may be. That's what ergonomics tells us, anyway.

Emanuel Lowi
Montreal, Quebec