Campy Record rear derailleur capacity question

Eagle Jackson

Will a Record medium cage derailleur work with a compact
(50-34) crank and 13-29 cassette? Or do I have to go to a
long cage?

Paul Kopit

On 27 Jun 2004 07:45:39 -0700, eaglejackson@hotmail.com (Eagle
Jackson) wrote:

>Will a Record medium cage derailleur work with a compact
>(50-34) crank and 13-29 cassette? Or do I have to go to a
>long cage?

IT will work fine as will the later vintage, standard cage
rear derailleurs.

A Muzi

Eagle Jackson wrote:

> Will a Record medium cage derailleur work with a compact
> (50-34) crank and 13-29 cassette? Or do I have to go to a
> long cage?

Yes and no.

A couple of days ago I removed a 53/39 on a 13/28 bike with
Campagnolo short changers, bolted on the customer's
requested 30-40-50 triple ( same BB). It shifted acceptably
for that customer but not acceptably, in our opinion, for a
new bicycle.

Since you own the medium changer, apparently, go ahead and
change the crank. Then decide if the loss of the 34-15 from
chain sag bothers you enough to buy a derailleur.

Derailleurs have ratings, which you will exceed, to allow
use of all gear combinations. Specifically, one _should_
change to a medium here, but since you apparently don't want
to, you don't have to - you'll get full use of the low and
high gears. Just not some of the near-crossover
combinations.

Since we are only the bearers of this news and find
ourselves at the short end of some hostility over it, I'll
close with this: There is some risk of the chain catching
on the outside bottom edge of the rear changer's cage in
the 34-13, wrecking the changer and the frame. Shortening
the chain to avoid that trades 'possible failure' for
'impending doom'.

--
Andrew Muzi www.yellowjersey.org Open every day since 1
April, 1971

Paul Kopit

On Sun, 27 Jun 2004 16:03:30 -0500, A Muzi <am@yellowjersey.org>
wrote:

>A couple of days ago I removed a 53/39 on a 13/28 bike with
>Campagnolo short changers, bolted on the customer's
>requested 30-40-50 triple ( same BB). It shifted acceptably
>for that customer but not acceptably, in our opinion, for a
>new bicycle.

With 50/34 the chain usually gets short enough so that it
won't tick the underside of the rear derailleur in 50/13.
With the newer, short cage varieties, the upper derailleur
pulley will not hit the 28 in the
34/28. In all cases, you can wrap the 50/28.

My wife's bike, 48/34 x 13/29 uses a 9sp std. cage Record
rear derailleur. I had to mount the 'b' tension screw on the
inside to get the pulley away from the 29 in 48/34.

My 2 bikes use up to 13/29 with 50/34 with newer front
derailleurs with no problems. Coincidently, my chain and my
Caryl's are the same length. Both Cannondales 56 and 49 cm.

Were I buying new parts, the Veloce rear derailleurs
work fine.

The only bicycle that needed a longer rear derailleur was
the tandem,
35/34 x 12/34.

Eagle Jackson

A Muzi <am@yellowjersey.org> wrote in message news:<10dudhbplh9jue9@corp.supernews.com>...
> Eagle Jackson wrote:
>
> > Will a Record medium cage derailleur work with a compact
> > (50-34) crank and 13-29 cassette? Or do I have to go to
> > a long cage?
>
> Yes and no.
>
> A couple of days ago I removed a 53/39 on a 13/28 bike
> with Campagnolo short changers, bolted on the customer's
> requested 30-40-50 triple ( same BB). It shifted
> acceptably for that customer but not acceptably, in our
> opinion, for a new bicycle.
>
> Since you own the medium changer, apparently, go ahead and
> change the crank. Then decide if the loss of the 34-15
> from chain sag bothers you enough to buy a derailleur.
>
> Derailleurs have ratings, which you will exceed, to allow
> use of all gear combinations. Specifically, one _should_
> change to a medium here, but since you apparently don't
> want to, you don't have to - you'll get full use of the
> low and high gears. Just not some of the near-crossover
> combinations.
>
> Since we are only the bearers of this news and find
> ourselves at the short end of some hostility over it, I'll
> close with this: There is some risk of the chain catching
> on the outside bottom edge of the rear changer's cage in
> the 34-13, wrecking the changer and the frame. Shortening
> the chain to avoid that trades 'possible failure' for
> 'impending doom'.

Thanks, this is very helpful.

Qui Si Parla Ca

eagle-<< Will a Record medium cage derailleur work with a
compact (50-34) crank and 13-29 cassette? Or do I have to go
to a long cage? >><BR><BR>

Will work fine. As a matter of fact, so will the short cage.

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St.
Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali
costruite eccezionalmente bene"