Max. cog for Campy long cage?

Hank Wirtz said:

Campy says 29t is the maximum cog size for their long cage rears, but
that's the biggest cog they make. Is a 32t wishful thinking?

-Hank

Hank:

Did you mean to write long cage or did you actually mean medium? 'Cuz
their long cage will easily support a 32. Think it would be okay - the
short cage will actually work fine with a 29t, according to the experts
and others here with practical experience using the short cage with a
29t. Applying the same idea to the medium, one might assume a 32 would
be within the realm of possibility for the medium.

D'ohBoy

"D'ohBoy" <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

Hank Wirtz said:

Campy says 29t is the maximum cog size for their long cage rears, but
that's the biggest cog they make. Is a 32t wishful thinking?

-Hank

Hank:

Did you mean to write long cage or did you actually mean medium? 'Cuz
their long cage will easily support a 32. Think it would be okay -
the short cage will actually work fine with a 29t, according to the
experts and others here with practical experience using the short cage
with a 29t. Applying the same idea to the medium, one might assume a
32 would be within the realm of possibility for the medium.

D'ohBoy

Except that maximum cog size doesn't have anything to do with cage
length. Cage length determines chain wrap capacity, but distance from
axle to guide pulley is what sets the max cog. Some long cage rears will
have different upper-body design than their short cage brethren, with
the assumption you'll be using big cogs. Conversely, short cage rears on
MTBs were a fad in the late '80s, that looked cool and you could get
away with if you didn't cross-chain.

FWIW, a 32 works with a long cage Veloce on my old Peugeot, but that has
a really long hanger. OTOH, a long cage Tiagra just barely clears a 30
on an early '80s Cannondale, whose hanger is a 1/4" shorter. I seem to
remember reading that Shimano released dropout design specs to be
considered SIS compatible, so I'm thinking most modern bikes will be
somewhere in between, and pretty well standardized.

Well, I just read on Andrew Muzi's web site that he's used a 34t with
Campy Long cage, so we'll see.

Thanks for replying!

Hank Wirtz said:

Campy says 29t is the maximum cog size for their long cage rears, but
that's the biggest cog they make. Is a 32t wishful thinking?

-Hank

Their longest cage will support a 11-34 w/o problem. Something I have
done on a few touring bicycles. shimano 9s 11-34, 10s ERGO and the long
cage RD from Campagnolo. The long cage's cage is as long as a MTB long
cage.

Hank Wirtz said:

Campy says 29t is the maximum cog size for their long cage rears, but
that's the biggest cog they make. Is a 32t wishful thinking?

-Hank

My tandem uses a Campy Centaur long cage rear derailleur and an XT
12/34 cassette. Before the current long cage models, the older longs
were similar to the current mediums. I've run 32t cogs with those.

The distance between the rollers of a Campy long and Shimano XT rear
derailleur are similar.

Hank Wirtz said:

Campy says 29t is the maximum cog size for their long cage rears, but
that's the biggest cog they make. Is a 32t wishful thinking?

Yes, we've set up Chorus Ergo tandems with 32 rear, no problem

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