RE: [CR]Inch Pitch Cog Conundrum

(Example: Framebuilders:Rene Herse)

From: Stephen James <sj52@hotmail.com>
To: devotion finesse <devotion_finesse@hotmail.com>, CR discussion list <classicrendezvous@bikelist.org>
Subject: RE: [CR]Inch Pitch Cog Conundrum
Date: Thu, 4 Sep 2008 03:05:18 +0000
In-Reply-To: <BLU113-W455BB08416339B6ACF0344F5590@phx.gbl>
References:


Hiya,
> My buddy has tried a number of 9T cogs on his bike but has had difficulty s> etting up a drivetrain in which there is no interference between the ch ain > and hub flange. It seems that most of the cogs he has obtained lack t he of> fset typical to a modern track cog. Is it possible that he has been trying> cogs intended for use on old balloon tire bikes rather than track b ikes?

In my limited experience, yes, some cogs for old balloon tires don't ha ve an offset. They are essentially flat. Funny you should ask, actually . I happened to be rummaging through an old closet and found a few inch pi tch cogs for pista bikes. They are all of slightly different thicknesses a nd have slightly different offsets.

If I lay them the cogs on a table face up, do the teeth touch (within a m m or so)? If so, could the difference be the hub or the crank. In addit ion, could he be using TA/Stronglight or another Dural chainring?

I have never had a problem mixing Italian with Italian inch pitch. The Bri tish cogs are designed somewhat differently from the Italian ones. However , when I lay them down together, the teeth all match up.

Steve James Bronx, NY USA _________________________________________________________________ Stay up to date on your PC, the Web, and your mobile phone with Windows
   Live. http://clk.atdmt.com/MRT/go/msnnkwxp1020093185mrt/direct/01/