> Date: Tue, 29 Dec 2009 12:57:06 -0500
> From: Wayne Bingham <veloclassique(AT)gmail.com>
> Subject: [CR] TA Pro 5 BIS Chain Ring Size and Tooth Count
> I just wanted to add a bit of information to this
> discussion. There are
> several types of TA Pro 5 "outer" rings. The more
> common is the model CY
> 205, which has the combination 50.4 5-pin BCD and 80 6-pin
> BCD drillings.
> These were available in 36t to 68t. There are also
> models 205 (3/32") and
> P205 (1/8") that have "single drilling" 50.4 5-pin
> BCD drilling only. These
> were available in 28t to 68t. In addition, there is a
> model T205 3/32" ring
> with "single drilling" 50.4 5-pin BCD that was
> designed for Trials (in the
> catalog, it specifically states "At the request of 'Trials'
> bicycle makers,
> T.A. have introduced a range of chainrings in FORTAL 2017
> A-T4 light alloy
> to meet their special requirements"). These were
> available in 19t to 25t.
> Just wanted to add what I could to the knowledge-base and
Thanks Wayne and everybody else. I'll check to see if the smaller rings are available through TA first, custom producers second, and advise the list. Having worked out the ratios I can say that from my perspective a well crafted 7 or 8 speed rear end coupled with a 44/20, or similar, makes a touring double that competes perfectly with a triple (any triple I ever made) for fine steps and range, while providing a narrow tread. That said, gears over 90" aren't of any use to me on a tourer, or on anything else these days ;>) .....sub 20" gears are!
"Trials"? In the context of the time I wonder if it wasn't really analogous to motorcycle trials, but more in line with the Technical Trials which involved modest loads and difficult terrain. Ernest Csuka would have been the person to ask; I wish it were still possible. I'll run it by TA in my email to them.
John Clay Tallahassee, Florida USA
Single Payer IS the compromise.