Re: [CR]Re: [Bulk] Re: Half-step on Sturmey

(Example: Books)

Date: Thu, 18 Sep 2008 12:56:47 -0500
To: "cmontgomery" <cmontgomery15@cox.net>, <classicrendezvous@bikelist.org>
From: "Mark Stonich" <mark@bikesmithdesign.com>
Subject: Re: [CR]Re: [Bulk] Re: Half-step on Sturmey
In-Reply-To: <011701c91945$07998830$d319a246@D687QV01>
References: <48CE3D89.9060804@verizon.net> <1262235490.20080915123431@rogers.com> <E1KfIj8-0004Zh-U3@elasmtp-spurfowl.atl.sa.earthlink.net>


At 11:14 PM 9/17/2008, cmontgomery wrote:
>BTW If you have an alloy shell you don't want very low gears on an FM
>unless you are a lightweight or a bit underpowered. The low gear
>pawls work in slots cut into the shell, unlike the AW/FW/S5 where are
>ramps in a continuous
>band. http://bikesmithdesign.com/SA/fm-fw-left-ball-cup.jpg A
>steel shell adequately supports these (for lack of a better word)
>crenellations.
>The old, thin, alloy shells flex enough that the pawls can bust these
>off http://bikesmithdesign.com/SA/fm-alloy-oops.jpg
>
>I have a spare alloy FM shell, but I'll be sneaking FW guts into it.
>
>Mark Stonich
>
> That is exactly what happened to mine Mark. I cried for days. Are you
>shure you really need that extra FM shell? I understand that one can use an
>AW shell for FM guts with a certain alteration. Is this the case? What needs
>to be done?
>
>Craig-down to an ASC, TF, FW, and AM- in Tucson

No alteration is needed to any shell that has a removable L.H. Ball cup. You just unscrew the FW/AW ball cup (left hand threads) and screw in the FM ball cup.

But I assume your L.H. FM ball cup is trashed. Do you have a source for a new one?

Someone wrote me, off list, that the earliest FM ball cups had proper ramped ratchets in a continuous band.

Mark Stonich;
     BikeSmith Design & Fabrication
       5349 Elliot Ave S. - Minneapolis. MN 55417
            Ph. (612) 824-2372 http://bikesmithdesign.com
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