Re: [CR]TA Pro 5 Vis on Fixed Wheel?

(Example: Events:Cirque du Cyclisme:2004)

Date: Thu, 7 Aug 2008 07:12:04 -0700 (PDT)
From: Jerome & Elizabeth Moos <jerrymoos@sbcglobal.net>
Subject: Re: [CR]TA Pro 5 Vis on Fixed Wheel?
To: Longleaf Bicycles <longleafbicycles@gmail.com>, classicrendezvous@bikelist.org
In-Reply-To: <50f0d99f0808062149v3e907423n49d9e635da2b1f09@mail.gmail.com>


TA made an absolutely bewildering variety of rings and adapters to fit those arms. It is true that some believe that, even for road use, the TA cranks has too much flex due to the small BCD of the outer ring. I don't really think the second ring does anything the stiffen things, as the flexing is going to be between the outside of the outer ring and its attachment to the crank arm. A track ring made for 1/8 inch chain is going to be thicker and stiffer than a road ring, but may still flex more than some would like.

However, TA made a number of different "adapters" which consisted of spiders which bolted to the arm in place of an outside chainring. These were much thicker and stiffer than an outer ring bolted direct to the arm. The chainrings themselves then had a much larger BCD and bolted to the adapter. Maybe the best known adapter is the Criterium adapter for 151 or 152 BCD Criterium rings. These were widely used In The Day by road racers and time trialists, and in fact I have a book published in the 70's with a photos of the great Beryl Burton using a TA Criterium adapter and rings on a Jacques Anquetil frame. It might be that the Criterium rings were available for 1/8 inch track chain and could be used with fixed gear, although of course shorter bolts would be required for attachment to the adapter. One would think the shorter bolts were made, if nothing else for use with a single 3/32 ring for time trial, as single chainring setups were widely used for TT In The Day.

Or it may be that TA made an adapter specitically for track use.

Regards,

Jerry Moos Big Spring, Texas, USA

Longleaf Bicycles <longleafbicycles@gmail.com> wrote: I'm looking for some cranks for a new fixed wheel project (modern frameset) and I'm not excited about current (non Record) single chainring crank offerings.

I have a spare set of TA Pro 5 crankarms, but have never used these on a fixed wheel bike. I am concerned that the lack of a second ring to stiffen the outer ring and the higher torque placed on the drivetrain of a fixed wheel bike makes the small BCD of the TA cranks unsuitable.

Is this a misplaced concern? Has anyone tried this? I don't care about a little flex and while it might be silly and an overestimation of my own power to think I'd bend a chainring the idea gave me enough pause that I thought I'd ask for some advice.

Anthony King
Longleaf Bicycles
805 B North Fourth St..
Wilmington, North Carolina 28401
910.341.3049 p
910.341.3059 f
longleafbicycles.com