In a message dated 11/15/03 7:48:15 AM Pacific Standard Time,
mpetry@bainbridgeisland.net writes:
> Jon hjertberg of wheelsmith had these jigs for a while - there may have
> been other sets as well. I could think of a way to do it with a lathe too. I
> know several people who have ridden cranks so modified. But it scares me a
> little bit, given what we already know about the failure modes of Campy
> crankarms. The factory campy NR "triple" arms had slightly thicker arms in the
> spider where the intermediate bolts went thru, and those arms had a threaded
> bushing to mount the inner ring. The modified arms simply use a bolt that
> threads right into the aluminum.
>
> At least for ME, the 42t middle ring does not represent an ideal triple
> setup. And I use Campy NR front derailleurs with all my TA cranks with no
> scraping. What's the problem?
>
I've had a Campy NR 180 set drilled for triple that has seen admittedly light
duty for almost 20 years and Ed has had no word of failures on any of the
ones that he and the other party drilled. I can check to see if there WERE any
that failed as a result of this, but I think the usual failures are in different
spots. Also, the kinds of people who use triples, tend to use spinnier gears.
>From prior CR threads and my own experience, Campagnolo failures are more
common with riders who use big gears and sprint a lot.
I need to spend some time with a gear chart and find what I would use as a
middle gear on a Campy triple set up.
T.A. cranks are lovely items, but in my youth, they scared me. I've always
been a bit of a big gear user (less so now) and the T.A.s flexed a lot in the
rings. In the early mountain bike days, I saw a lot of broken T.A. arms. The
word on the alloy, was (and is) that it's on the soft side.
I know there have been a lot of great miles put on T.A. crank arms, but I
made a decision that I personally would rather put up with a known set of
problems around Campy crank arms in part because the metal is better. For me, T.A. is
not an option.
Stevan Thomas
Alameda, CA