Re: [CR] 13 Tooth SunTour Perfect FW Cog

(Example: Framebuilders:Doug Fattic)

Date: Fri, 8 Jan 2010 12:03:52 -0600
To: <john@os2.dhs.org>, <classicrendezvous@bikelist.org>
From: "Mark Stonich" <mark@bikesmithdesign.com>
In-Reply-To: <4B475919.1050404@att.net>
References: <819772.31285.qm@web31403.mail.mud.yahoo.com> <E1NT7Bt-00078M-SD@elasmtp-curtail.atl.sa.earthlink.net>
Subject: Re: [CR] 13 Tooth SunTour Perfect FW Cog


At 1/8/2010 10:11 AM -0600, John Thompson wrote:
>On 01/07/2010 11:16 PM, Mark Stonich wrote:
>
> > Too bad they didn't do this make Ultra spaced 7 speeds on Ultra 6
> > bodies. Would have made for better touring FWs than the New Winners
> > with only two splined positions and a largest threaded cog of 21t
>
>Are you referring to ProCompe/Perfect bodies? Because Ultra-spaced
>7-speeds were available for Winner bodies.

True but you couldn't build a good touring FW on them. 5th cog was threaded so your last 3 cogs would be 21-?-34 (or 38) (Much of this was before 74mm BCD inner rings.)

I had several work arounds for various customers.

1. Silver brazing a 14t to a 16t (or a 16 to an 18) to turn an Ultra 6 Pro Compe FW into an Ultra 7. When I did these I'd also replace the inner body with a 5 speed tandem inner body to get the nearly 2x wider pawls. The biggest ones I made were 16-38s. One of these was used in conjunction with 16-32-42-45 "chainrings". His plan was to ride up Machu Picchu with all the gear needed for a ride to Patagonia.

2. Fabricate a threaded 23 or 24t by silver brazing a splined cog to a ring made from a smaller threaded cog.

3. Eventually I designed QBP's first in-house product, the Low Gear Adapter. This was a ring with 44mm threads on the inside and splines on the outside, giving 4 splined positions on a New Winner. Even though Frank Berto gave it thumbs up in Bicycling, only the 1st batch of 200 were sold as not many shops had QBP accounts back then.

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