Ultegra triple, 12-34 cassette and LBS I don't trust

[Mark A. Clark]

A friend of mine recently purchased a a tandem - a very nice Co-motion - but I question the way the
bike shop set it up. In all honesty, I admit I don't trust or like the bike shop guy. He smiles as
if he is posing for a picture all the time.

About the bike: I think Co-Motion supplies a typical tandem with 12-34 cogset and Shimano's XTR
derailleur combination, which is designed to handle this cog arrangement. This Fresno bike shop must
have removed the XTR and put on an Ultegra derailleur (triple) to handle the 12-34 cogs. But Shimano
clearly states that the Ultegra triple can only handle up to a 27 tooth cog (12-27). An email from
Co-Motion said the same thing. The guy in Fresno disputes this. Anyway, my friend finally accepted
the argument and asked the guy to replace the 12-34 with a 12-27 arrangement. However, the
chainrings on the tandem are 54, 44, 32 and she would prefer to have the 12-34,

I'm not saying it won't work. I have a friend who has used the XT 12-32 with an Ultegra rear
derailleur on the climb to Kaiser and it worked fine, but a bike shop should not sell it that way in
my opinion. I think she should press them for the XTR derailleur or at least an XT.

Opinions?

REMOVE OBVIOUS TO REPLY

 

[Mike Jacoubowsk]

> I'm not saying it won't work. I have a friend who has used the XT 12-32 with an Ultegra rear
> derailleur on the climb to Kaiser and it worked fine, but a bike shop should not sell it that way
> in my opinion. I think she should press them for the XTR derailleur or at least an XT.

Simple solution- have the shop put it into a stand and demonstrate that it works. In particular,
make sure that it safely goes into the large/large combination. If somebody tries to tell you
that you'd never ride in that gear, well... you'd never *intentionally* ride in that gear, but
you're tired, it's a hot day, the grade just got a little steeper, and you just naturally reach
for that next-lower gear in the rear, not paying attention to the fact that you're on the large
chainring up front.

If the derailleur passes that test, and will also work in the 3rd-smallest cog (and larger) in the
rear when it's in the smallest front sprocket, then you're fine. If it doesn't, then a different
derailleur (one that's made for a wider range) is indicated.

--Mike-- Chain Reaction Bicycles http://www.ChainReactionBicycles.com

"Mark A. Clark" <[email protected]> wrote in message
news:[email protected]...
> A friend of mine recently purchased a a tandem - a very nice Co-motion - but I question the way
> the bike shop set it up. In all honesty, I admit I don't trust or like the bike shop guy. He
> smiles as if he is posing for a picture all the time.
>
> About the bike: I think Co-Motion supplies a typical tandem with 12-34 cogset and Shimano's XTR
> derailleur combination, which is designed to handle this cog arrangement. This Fresno bike shop
> must have removed the XTR and put on an Ultegra derailleur (triple) to handle the 12-34 cogs. But
> Shimano clearly states that the Ultegra triple can only handle up to a 27 tooth cog (12-27). An
> email from Co-Motion said the same thing. The guy in Fresno disputes this. Anyway, my friend
> finally accepted the argument and asked the guy to replace the 12-34 with a 12-27 arrangement.
> However, the chainrings on the tandem are 54, 44, 32 and she would prefer to have the 12-34,
>
> I'm not saying it won't work. I have a friend who has used the XT 12-32 with an Ultegra rear
> derailleur on the climb to Kaiser and it worked fine, but a bike shop should not sell it that way
> in my opinion. I think she should press them for the XTR derailleur or at least an XT.
>
> Opinions?
>
> REMOVE OBVIOUS TO REPLY

 

[Peter]

Mark A. Clark wrote:

> A friend of mine recently purchased a a tandem - a very nice Co-motion - but I question the way
> the bike shop set it up. In all honesty, I admit I don't trust or like the bike shop guy. He
> smiles as if he is posing for a picture all the time.
>
> About the bike: I think Co-Motion supplies a typical tandem with 12-34 cogset and Shimano's XTR
> derailleur combination, which is designed to handle this cog arrangement. This Fresno bike shop
> must have removed the XTR and put on an Ultegra derailleur (triple) to handle the 12-34 cogs. But
> Shimano clearly states that the Ultegra triple can only handle up to a 27 tooth cog (12-27). An
> email from Co-Motion said the same thing. The guy in Fresno disputes this. Anyway, my friend
> finally accepted the argument and asked the guy to replace the 12-34 with a 12-27 arrangement.
> However, the chainrings on the tandem are 54, 44, 32 and she would prefer to have the 12-34,
>
> I'm not saying it won't work. I have a friend who has used the XT 12-32 with an Ultegra rear
> derailleur on the climb to Kaiser and it worked fine, but a bike shop should not sell it that way
> in my opinion.

I agree that even if it does work it's not something that should be accepted on a new bike.
Tandems generally need wide-range gearing so I don't think your friend should settle for the 12-27
cassette instead of the 12-34 she was expecting. Either the XT or XTR derailleur should be fine
with the 12-34.

 

[Qui Si Parla Ca]

Mark-<< But Shimano clearly states that the Ultegra triple can only handle up to a 27 tooth cog (12-
27). An email from Co-Motion said the same thing. The guy in Fresno disputes this. Anyway, my friend
finally accepted the argument and asked the guy to replace the 12-34 with a 12-27 arrangement.
However, the chainrings on the tandem are 54, 44, 32 and she would prefer to have the 12-34,

I'm not saying it won't work. I have a friend who has used the XT 12-32 with an Ultegra rear
derailleur on the climb to Kaiser and it worked fine, but a bike shop should not sell it that way in
my opinion. I think she should press them for the XTR derailleur or at least an XT.

Opinions? >><BR><BR>

It's all about chain length. The shorter cage of the ultegra triple will shift the chain up the
cogset but he may have droopy chain in small ring/smallish cog combos or chain/pulley noise in
smaller rings/biggest cogs or not enough chain for big/big combo. A longer cage rear der is the best
answer, period.

An ultegra long cage will handle bigger than 27t cogs(biggest shimano offers in a 'road' cogset),
but again, with bigger big cog cogsets, a longer cage, with more chain, is the best idea.

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

 

[Richard Chan]

Peter <[email protected]> wrote in message news:<27MLb.10300$Rc4.43550@attbi_s54>...
> Mark A. Clark wrote: >> .. In all honesty, I admit I don't trust or like the bike shop guy. He
> smiles as if he is posing for a picture all the time. >>



Not sure what the shop owner's motive is but it could be about more profit if he charges the same
for the Ultegra triple rear. Business is tough (for shops)now and that's why I don't post discount
coupon codes anymore.

 

[Sheldon Brown]

Qui si parla Campagnolo wrote:

> Mark-<< But Shimano clearly states that the Ultegra triple can only handle up to a 27 tooth cog
> (12-27). An email from Co-Motion said the same thing. The guy in Fresno disputes this. Anyway, my
> friend finally accepted the argument and asked the guy to replace the 12-34 with a 12-27
> arrangement. However, the chainrings on the tandem are 54, 44, 32 and she would prefer to have
> the 12-34,
>
> I'm not saying it won't work. I have a friend who has used the XT 12-32 with an Ultegra rear
> derailleur on the climb to Kaiser and it worked fine, but a bike shop should not sell it that way
> in my opinion. I think she should press them for the XTR derailleur or at least an XT.

Peter Chisholm replied:

> It's all about chain length. The shorter cage of the ultegra triple will shift the chain up the
> cogset but he may have droopy chain in small ring/smallish cog combos or chain/pulley noise in
> smaller rings/biggest cogs or not enough chain for big/big combo. A longer cage rear der is the
> best answer, period.
>
> An ultegra long cage will handle bigger than 27t cogs(biggest shimano offers in a 'road' cogset),
> but again, with bigger big cog cogsets, a longer cage, with more chain, is the best idea.

Shimano's spec of 27 tooth max is very conservative. In my experience, all Shimano rears, long or
short cage, will generally work fine with 30 tooth sprockets (We have a lot of experience with this,
'cause we sell a _lot_ of our "Century Special" 13-30 cassettes.)

See also: http://sheldonbrown.com/gloss_ca-m.html#capacity

With a short cage rear mech, or with an extra wide range in front, droop can be an issue in the
small/smallish combinations, though droop is not all that serious a "problem" if the rider has
reasonable shifting habits.

I will categorically state that the chain MUST be long enough to shift on and off the large/large
combination.

Going bigger than 30 in back with any of Shimano's "road" models gets dicey because the derailer's
jockey pulley is likely to bump up against the large sprocket.

I have heard of people getting long cage "road" derailers, such as the Ultegra triple, to work with
a 32 tooth, but don't know of any case where such a derailer will work properly with a 34.

The design of the bike's derailer mounting tab does enter into this, so I can't say it's impossible
that it might be made to work, but I'll believe it when I see it.

Sheldon "Pushing The Envelope" Brown +---------------------------------------------------------+
| I don't like spinach, and I'm glad I don't, because | if I liked it I'd eat it, and I just hate
| it. | --Clarence Darrow |
+---------------------------------------------------------+ Harris Cyclery, West Newton,
Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts
shipped Worldwide http://captainbike.com http://sheldonbrown.com

 

[Mike Jacoubowsk]

> Not saying this doesn't happen but it's sometimes hard for me to
understand why
> the shop would wish to get a few bucks now with the possibility of losing
a
> customer or having something break, both of which would cost him more.

It's also difficult to believe that a shop would choose to try and save a pretty small number of
dollars on such an expensive customer purchase. It seems like there must be something more to this
story than just dollars and cents.

--Mike-- Chain Reaction Bicycles www.ChainReaction.com

"Qui si parla Campagnolo" <[email protected]> wrote in message news:20040110103323.09564.00002787@mb-
m17.aol.com...
> Richard-<< Not sure what the shop owner's motive is but it could be about
more
> profit if he charges the same for the Ultegra triple rear. Business is tough (for shops)now
> >><BR><BR>
>
> Not saying this doesn't happen but it's sometimes hard for me to
understand why
> the shop would wish to get a few bucks now with the possibility of losing
a
> customer or having something break, both of which would cost him more.
>
> Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
> (303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[Richard Chan]

[email protected] (Qui si parla Campagnolo) wrote in message news:<[email protected]>...
> Not saying this doesn't happen but it's sometimes hard for me to understand why the shop would
> wish to get a few bucks now with the possibility of losing a customer or having something break,
> both of which would cost him more.

May be that's why you are much more successful than many other shops. You even "warranty" parts that
you didn't sell and that makes friends for life.

 

[B.C. Cletta]

"Mark A. Clark" <[email protected]> wrote in message news:<[email protected]>...
> A friend of mine recently purchased a a tandem - a very nice Co-motion - but I question the way
> the bike shop set it up. In all honesty, I admit I don't trust or like the bike shop guy. He
> smiles as if he is posing for a picture all the time.
>
> About the bike: I think Co-Motion supplies a typical tandem with 12-34
^^^^^ verify before proceeding.

> cogset and Shimano's XTR derailleur combination, which is designed to handle this cog arrangement.
> This Fresno bike shop must have removed the XTR and put on an Ultegra derailleur (triple) to
> handle the 12-34 cogs. But Shimano clearly states that the Ultegra triple can only handle up to a
> 27 tooth cog (12-27). An email from Co-Motion said the same

did Co-Motion say that it was equipped w/ a XTR? (i read this as them saying an Ultegra is good
for a 27.)

> thing. The guy in Fresno disputes this. Anyway, my friend finally accepted the argument and asked
> the guy to replace the 12-34 with a 12-27 arrangement. However, the chainrings on the tandem are
> 54, 44, 32 and she would prefer to have the 12-34,

irrespective of that other stuff, i'd change the front to a 24 from the 32. i've found a 24x28 w/
26-in wheels (25-in actual dia) to be adequate for road rides w/o panniers. i'm a big believer in
upshifting from a too low low gear because you can't downshift from a too high low gear. and it's
a minor fix to the other stuff w/ a 24x27 or 24x30 low.

> I'm not saying it won't work. I have a friend who has used the XT 12-32 with an Ultegra rear
> derailleur on the climb to Kaiser and it worked fine, but a bike shop should not sell it that way
> in my opinion. I think she should press them for the XTR derailleur or at least an XT.
>
> Opinions?

come clean, ID the bike shop. are you dealing w/ the owner or some minion?

> REMOVE OBVIOUS TO REPLY
(damn, forgot to remove it.)