Re: [CR] BBs for TA Pro 5 Vis cranksarms: old vs. new, symmetrical or not, taper styles

(Example: Framebuilders:Masi)

In-Reply-To: <E1LqxxM-0006Md-NM@elasmtp-spurfowl.atl.sa.earthlink.net>
References:
Date: Mon, 6 Apr 2009 20:36:40 -0700
To: "Roman Stankus" <rstankus@mindspring.com>, 'Adam Hammond' <anhammond@gmail.com>, 'CR discussion list' <Classicrendezvous@bikelist.org>
From: "Jan Heine" <heine94@earthlink.net>
Subject: Re: [CR] BBs for TA Pro 5 Vis cranksarms: old vs. new, symmetrical or not, taper styles


At 7:09 PM -0400 4/6/09, Roman Stankus wrote:
>Last year I spoke with Mike Barry about the compatability of TA cranks with
>bottom brackets - he said that they work with campy NR BB's fine. I still
>haven't set one up (TA) so I can't say from personal experience - but I know
>Mike has had a lot of experience with them over the years so I trust his
>advise.

Campagnolo NR BB spindles are 114 mm wide, so a tad narrower than the old TAs. I have used a re-machined Campagnolo NR spindle with Stronglight 49D cranks in a Singer BB I made. Clearances are OK, but if you had a 130 mm rear end (mine is 126 mm), you might be cutting it too close for comfort. (I also selected carefully among a stash of cranks for those that mated as I wanted.)

The ideal BB for a "modern" TA setup would be about 116-118 mm long, and slightly asymmetric. For my Grand Bois Urban Bike, I used a symmetric 116 mm JIS spindle in a not-yet-available cartridge BB, and it mated very nicely with the tapers of an old TA crank. I did put a small (2-3 mm) fixed cup spacer on the right side to move the BB just a bit off-center. The length is perfect, and I believe the bike has 130 mm rear spacing. (I re-spaced a 135 mm Maxi-Car hub for it, but don't remember the measurement.)

Surprisingly, the JIS spindle mated well, even though I believe that when new, TA used an ISO taper. The Campagnolo NR is ISO... So perhaps the TA cranks are in between?

Jan Heine
Editor
Bicycle Quarterly
140 Lakeside Ave #C
Seattle WA 98122
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