Re: [CR]Unusual frame design on eBay - Caselli track bike

(Example: Production Builders:Cinelli)

From: "nicholas harteau" <nrh@ikami.com>
To: <hsachs@alumni.rice.edu>
In-Reply-To: <49497E35.20002@verizon.net>
Subject: Re: [CR]Unusual frame design on eBay - Caselli track bike
Date: Wed, 17 Dec 2008 19:29:55 -0500
References: <49497E35.20002@verizon.net>
cc: Classic Rendezvous <classicrendezvous@bikelist.org>

I've seen a few frames like this, always in small sizes. Given the same (virtual) tt height and head tube angle, it allows a lower standover height and larger front wheel. Or, another way of looking at it: less fork rake, steeper head-tube angle, same standard-sized wheel. It trades off torsional stiffness for more geometry options in small frame sizes.

But, I could be wrong.

On Dec 17, 2008, at 5:33 PM, Harvey Sachs wrote:
> The frame design depicted increases the ability of the front end to
> track independently of the rear end, since it makes it easier for
> the axis of the steering apparatus to diverge from parallel with the
> seat tube. At the same time, it adds to the ability of the fork to
> absorb shock, by making it easier to twist around the "X" and
> momentarily shorten the wheelbase. I regard both attributes as
> "counterintuitive features," which might be marketer-speak for
> "really weird ways to make a track bike work less well." But, I
> could be wrong.
>
> harvey sachs
> mcLean va.
>
> Harry Travis asked:
> What understanding (or misunderstanding) of the forces on a bike
> would lead someone to build this frame? What problem does it solve?
> What weaknesses does it create? (I notice that with a smaller front
> wheel, more space has been furnished to the rider for her feet, and
> the headtube can be made longer.)
>
> >>
> >> Never seen a frame like this:
> >>
> >>
> >> http://ebay.com/<blah>
> >> _______________________________________________
> _______________________________________________

--
nicholas harteau
nrh@ikami.com
brooklyn, ny