One factor that sometimes requires attention is the total width of the freewheel, as opposed to the spacing between the sprockets. Freewheels with a raised lip behind the largest sprocket (e.g. Suntour and Shimano), are a few millimeters wider than those whose largest sprocket simply threaded onto the body (e.g. Regina.)
The wider freewheels sometimes caused problems with Italian frames that were built under the assumption that only a Regina freewheel would be used in the frame. The critical factor is the manner in which the inner surface of the drive side seat stay is attached to the dropout. In fact, sometimes I wonder if this is the reason that French frames used 122mm spacing rather than 120mm.
In any event, I'm mentioning this because it can cause problems
particularly when trying to use a narrow 6 sprocket freewheel
("Ultra Six") in an older Italian frame.
Cheers,
Fred Rednor - Arlington, Virginia (USA)
> This stuff is inexact, so you often saw 5 speed spaced more
> like 122. The 6 speed could be a mm or two off the nominal
> 126 mm. The "Ultra 6" was a SunTour trademark and I do think
> they originated the design, but several others, including
> Maillard, copied it.
>
> I believe SunTour did offer a narrow chain with the Ultra
> 6, but I never bought one. The SedisSport chains worked with
> no problem. Not sure I ever tried an older 3/32 chain like
> Regina Extra with an Ultra 6. Those I generally reserved for
> use with Regina FW's. Didn't shift as well as a
> SunTour/SedisSport combo, but more correct on Italian bikes.
>
> Regards,
>
> Jerry Moos
> Big Spring, TX
>
>
> FujiFish1@aol.com wrote:
>
> Howard,
> Just in case no one else answers, 5 speed spacing was/is
> 120mm. Some 6 spee
> d
> freewheels were made a bit thinner between the cogs, allowing
> a fit inside a
>
> 120mm space. They were known as "Ultra 6" speed, and required
> specially
> spaced chains, IIRC.
>
> Standard 6 speed spacing, however, is 126mm. Subsequently,
> Ultra 7 speeds
> showed up, fitting within the 126mm space, and then there
> were standard 7 sp
> eeds
> ... but all this drifts off topic.
>
> Ciao,
> Mark Agree
> Southfield MI
> ~ ~ ~
>
>
>
> Date: Mon, 18 Jun 2007 16:03:08 -0400
> From: hvulpus@aol.com
> To: classicrendezvous@bikelist.org
> Subject: [CR]rear spacing Campy 6 speed
>
>
> I would like to ask a terribly naive question, except, of
> course, if you don
> 't know the answer, which I don't.Â
>
>
>
> What is the rear spacing for the old style 6 speed bikes? I
> believe the newe
> r 8, 9, 10 speed are 130 mm.
>
>
>
> Best,
>
>
>
> Howard
>
> Swarthmore, PA
>
> howard.bloch@yale.edu
>
>
>
>
>
> ************************************** See what's free at
> http://www.aol.com
> .
>
>
> _______________________________________________
>
>
>
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