[CR]Fwd: Re Soviet Takhion track bike


Example: Events:Cirque du Cyclisme:2004

Date: Thu, 6 Mar 2008 08:21:48 -0800 (PST)
From: Tom Dalton <tom_s_dalton@yahoo.com>
To: Classic Rendezvous <classicrendezvous@bikelist.org>
Subject: [CR]Fwd: Re Soviet Takhion track bike

Date: Thu, 6 Mar 2008 08:21:16 -0800 (PST) From: Tom Dalton <tom_s_dalton@yahoo.com> Subject: Re Soviet Takhion track bike To: devotion_finesse@hotmail.com

In some sense there has to be a bearing, because there is a load and something is taking that load. So, it's possible that the steerer is just grinding away in the inside of the headtube, but that would still be a crude plain bearing of sorts. Or maybe not... maybe a third part is required to constitute a true plain bearing, technically speaking. In any case, upper headsets are very different from lower because the enountered thrust loads tend to unload the upper, while they load the lower. Also, while there is a radial load on both, on the upper I think it's mostly an opposite-direction load from that at the lower bearing, in response to torque around the lower bearing.

The bottom line is that there is very little demand on the upper bearing in terms of thrust, and the load is mostly radial. A needle bearing or even a plain bearing would work up top, as long as there was something to take up the thrust load which, loosely speaking, would be limited to keeping the weight of the fork and wheel from causing the front of the bike fall off when you pick it up.

Tom Dalton Bethlehem PA USA

Is it possible that there is no upper headset bearing? I can't imagine how any race might be fitted internally.

He has LOTS of nice track bikes...and NO furniture in his house. Think it's safe to say that he's probably a bachelor?

Matthew Bowne Brooklyn, New York

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