32 Sprocket with Campag Chorus?

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Roger_H
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32 Sprocket with Campag Chorus?

Postby Roger_H » 21 Jul 2019, 3:57pm

I have a Campag Chorus rear mech which runs fine with a 29 sprocket.

It is a 2010 mech which was just a standard length cage - ie short in today's terminology.

Has anyone tried running similar with a 32 sprocket?

(And, yes, I realise that cross chaining would not be on - but that's not something I do anyway and that c/stay length has an impact on how snappy the changing is).

But the big Q is would it work or would the cage just grind into the sprockets?

Has anyone had an issue and resolved with WolfsTooth extended hanger?

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Mick F
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Re: 32 Sprocket with Campag Chorus?

Postby Mick F » 21 Jul 2019, 4:44pm

Works absolutely fine with a 30t, and I have no reason to doubt that it would work with 32t

Main issue is total capacity.
Cage length is what counts.

From my experience, the parallelograms are the same, but the cages come in short and medium for Chorus, but medium and long for other mechs. I run a Campag Comp rear mech now, and it's exactly the same geometry as my old Chorus. Chorus has a carbon outer plate on the parallelogram, but the rest of it is identical.

Cage length is what counts.
12-30 cassette with a 28/42/53 chainset.
(30 - 12) + ( 53 - 28) = 18 - 25 = 43 total capacity and it works absolutely fine.
Mick F. Cornwall

Brucey
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Re: 32 Sprocket with Campag Chorus?

Postby Brucey » 21 Jul 2019, 6:24pm

IMHO you need to set this up so that you can run big-big if necessary, and put up with the slack chain in small-small. The reason is that otherwise sooner or later you will accidentally select that gear and if there isn't enough chain length you will break something, possibly everything...

I'm sure it will work on a 32T provided you use a hanger extender, but the shifting on the smaller sprockets won't be as good.

If you want to increase the total capacity of the mech you may be able to buy the longer side plates for the mech and convert it to a longer cage.

cheers
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Roger_H
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Re: 32 Sprocket with Campag Chorus?

Postby Roger_H » 21 Jul 2019, 6:45pm

Mick F wrote:Works absolutely fine with a 30t, and I have no reason to doubt that it would work with 32t

Main issue is total capacity.
Cage length is what counts.

From my experience, the parallelograms are the same, but the cages come in short and medium for Chorus, but medium and long for other mechs. I run a Campag Comp rear mech now, and it's exactly the same geometry as my old Chorus. Chorus has a carbon outer plate on the parallelogram, but the rest of it is identical.

Cage length is what counts.
12-30 cassette with a 28/42/53 chainset.
(30 - 12) + ( 53 - 28) = 18 - 25 = 43 total capacity and it works absolutely fine.

Thanks,
Cage length only becomes an issue if you want to run "big-big" or close to that - which I don't. The 32 would give me 34x32 ie a slightly lower crawler gear. But I cannot see any reason to want to run 50x32.
So my only issue is the cage fouling on the cassette.

Roger_H
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Re: 32 Sprocket with Campag Chorus?

Postby Roger_H » 21 Jul 2019, 6:48pm

Brucey wrote:IMHO you need to set this up so that you can run big-big if necessary, and put up with the slack chain in small-small. The reason is that otherwise sooner or later you will accidentally select that gear and if there isn't enough chain length you will break something, possibly everything...

I'm sure it will work on a 32T provided you use a hanger extender, but the shifting on the smaller sprockets won't be as good.

If you want to increase the total capacity of the mech you may be able to buy the longer side plates for the mech and convert it to a longer cage.

cheers


I don't get into 50x29 now - It's never an issue as you don't suddenly end up in such low gears by accident (at least imho).

You mention the hanger extension, but my Q is do you have actual experience of running a 2010 Chorus mech and a 32 sprocket with a/o w/o an hanger extension?

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Re: 32 Sprocket with Campag Chorus?

Postby Brucey » 21 Jul 2019, 6:54pm

I've run lots of other RDs on hanger extenders and they have worked as described. I don't expect yours to be any different, except to note that frames, gear hangers and goodness knows what else vary slightly and this can be more important than the name writ upon the rear mech otherwise.

I've seen lots of people with short chains and big sprockets who have blithely said "oh, I'll never use that gear" and they have been wrong (*).

[edit; (*) well actually they have been right, but just not in the way they expected it.....]

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Mick F
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Re: 32 Sprocket with Campag Chorus?

Postby Mick F » 22 Jul 2019, 8:09am

If you cannot do big/big all hell will break loose if you accidentally try to select it.
Just coz you don't want to use the big sprocket and the big ring (at the same time) is besides the point.

You MUST be able to select it, even if you don't to.
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tatanab
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Re: 32 Sprocket with Campag Chorus?

Postby tatanab » 22 Jul 2019, 8:27am

Agree with Mick F. In cases where I have gone beyond the capacity of a mech I have always set it so that the chain runs slack in little/little because that is a combination I truly would never use whereas big/big I do use in some circumstances.

Roger_H
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Re: 32 Sprocket with Campag Chorus?

Postby Roger_H » 22 Jul 2019, 9:01am

tatanab wrote:Agree with Mick F. In cases where I have gone beyond the capacity of a mech I have always set it so that the chain runs slack in little/little because that is a combination I truly would never use whereas big/big I do use in some circumstances.


With an 11spd block there are enough sprockets not to need bib-big whereas small-small is, for me, sometimes useful. But those discussions relate more to the ring and sprocket choices.

And for me the Q is what will the rear mech actually take.

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RickH
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Re: 32 Sprocket with Campag Chorus?

Postby RickH » 22 Jul 2019, 10:05am

Roger_H wrote:With an 11spd block there are enough sprockets not to need bib-big whereas small-small is, for me, sometimes useful. But those discussions relate more to the ring and sprocket choices.

And for me the Q is what will the rear mech actually take.

It isn't really a matter of needing the gear or wanting to use it. On my 3x10 I would not normally use the largest 2 sprockets with the big chainring but there have been a couple of occasions when I have thought I was in the middle ring & gone to change down a gear to find I couldn't because I was actually on the big ring & had reached the largest sprocket.

If the chain is too short, even if it doesn't actually damage anything, you can sometimes need to partially dismantle the drive train (& you won't be able to release a quick link) to get it back out of that gear.

In contrast a slack chain in small-small is unlikely to do any damage.

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Re: 32 Sprocket with Campag Chorus?

Postby Roger_H » 22 Jul 2019, 10:27am

RickH wrote:
Roger_H wrote:With an 11spd block there are enough sprockets not to need bib-big whereas small-small is, for me, sometimes useful. But those discussions relate more to the ring and sprocket choices.

And for me the Q is what will the rear mech actually take.

It isn't really a matter of needing the gear or wanting to use it. On my 3x10 I would not normally use the largest 2 sprockets with the big chainring but there have been a couple of occasions when I have thought I was in the middle ring & gone to change down a gear to find I couldn't because I was actually on the big ring & had reached the largest sprocket.

If the chain is too short, even if it doesn't actually damage anything, you can sometimes need to partially dismantle the drive train (& you won't be able to release a quick link) to get it back out of that gear.

In contrast a slack chain in small-small is unlikely to do any damage.

Again the real Q for me is whether anyone has personal experience of running a 2010 Chorus mech with a 32 sprocket?

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Re: 32 Sprocket with Campag Chorus?

Postby Brucey » 22 Jul 2019, 11:09am

it depends how long your gear hanger is (this affects the clearance), and what size your chainrings are (this affects the amount of the mech capacity that is used) and the exact chain length (which is amongst other things a function of chainstay length/chainring size) and a few other things.

Its almost certain (with any sensible combination of chainrings and an 11-32T cassette) that you will exceed the total capacity of the derailleur as well as the maximum sprocket size. If the mech is normally rated to 30T then 32T requires only 4mm extra clearance; between a bit of leeway in the specs, an bit of adjustment and (say) a slightly longer than normal gear hanger you will be able to use a 32T. However not all frames will allow it so it is a question of trying it and seeing how it goes.

If the total capacity of the mech is exceeded then you should definitely make the chain long enough to be able to use big-big safely and put up with the slack chain in the small-small combinations.

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Mick F
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Re: 32 Sprocket with Campag Chorus?

Postby Mick F » 22 Jul 2019, 4:13pm

Roger_H wrote:Again the real Q for me is whether anyone has personal experience of running a 2010 Chorus mech with a 32 sprocket?
Not me, but I had a Chorus medium cage in regular and constant use with a 12-30 Centaur cassette and a 53/42/30 Chorus chainset and Chorus Ergos.

I have no doubt whatsoever if I'd found a 12-32 cassette (if such a thing exists?) it would have worked perfectly.

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gfk_velo
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Re: 32 Sprocket with Campag Chorus?

Postby gfk_velo » 22 Jul 2019, 7:36pm

Roger_H wrote:
RickH wrote:
Roger_H wrote:With an 11spd block there are enough sprockets not to need bib-big whereas small-small is, for me, sometimes useful. But those discussions relate more to the ring and sprocket choices.

And for me the Q is what will the rear mech actually take.

It isn't really a matter of needing the gear or wanting to use it. On my 3x10 I would not normally use the largest 2 sprockets with the big chainring but there have been a couple of occasions when I have thought I was in the middle ring & gone to change down a gear to find I couldn't because I was actually on the big ring & had reached the largest sprocket.

If the chain is too short, even if it doesn't actually damage anything, you can sometimes need to partially dismantle the drive train (& you won't be able to release a quick link) to get it back out of that gear.

In contrast a slack chain in small-small is unlikely to do any damage.

Again the real Q for me is whether anyone has personal experience of running a 2010 Chorus mech with a 32 sprocket?


You won't believe it - but it was a combination that was both computer modelled and practically tested at Campagnolo.
It was rejected in favour of spending a lot of R and D time in making the HO RDs with Medium cage. OK, there were also other reasons to do that but given the slating that Campag were getting at the time for not having a "32T solution", if it could have been made to work well and predictably, believe me, they'd have done it - there was a lot of pressure from the sales side.

Probably you can get it to work in some cases, depending on the exact frame geo (as I have discussed on this and other forums many times) but I'd be careful - I know for a fact Campagnolo broke a lot of mechs in testing, sometimes for obvious reasons, sometimes for not-so-obvious reasons ... I rode one of the bikes at the factory and I thought the shifting was barely acceptable ...
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Roger_H
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Re: 32 Sprocket with Campag Chorus?

Postby Roger_H » 22 Jul 2019, 7:51pm

gfk_velo wrote:
Roger_H wrote:
RickH wrote:It isn't really a matter of needing the gear or wanting to use it. On my 3x10 I would not normally use the largest 2 sprockets with the big chainring but there have been a couple of occasions when I have thought I was in the middle ring & gone to change down a gear to find I couldn't because I was actually on the big ring & had reached the largest sprocket.

If the chain is too short, even if it doesn't actually damage anything, you can sometimes need to partially dismantle the drive train (& you won't be able to release a quick link) to get it back out of that gear.

In contrast a slack chain in small-small is unlikely to do any damage.

Again the real Q for me is whether anyone has personal experience of running a 2010 Chorus mech with a 32 sprocket?


You won't believe it - but it was a combination that was both computer modelled and practically tested at Campagnolo.
It was rejected in favour of spending a lot of R and D time in making the HO RDs with Medium cage. OK, there were also other reasons to do that but given the slating that Campag were getting at the time for not having a "32T solution", if it could have been made to work well and predictably, believe me, they'd have done it - there was a lot of pressure from the sales side.

Probably you can get it to work in some cases, depending on the exact frame geo (as I have discussed on this and other forums many times) but I'd be careful - I know for a fact Campagnolo broke a lot of mechs in testing, sometimes for obvious reasons, sometimes for not-so-obvious reasons ... I rode one of the bikes at the factory and I thought the shifting was barely acceptable ...


Thanks indeed! The Chorus mech is supposed to be the same geometry as the Record and S Record and I guess the Chorus mechs are cheaper to trash. I can also understand the commercial imperative to match the larger bottom sprockets Shimano and SRAM were offering.

So it sounds like if I want decent changing, and not either have a lot of slack chain slapping around (with the likelihood of shipping the chain) I ought to get a post 2010 Chorus mech with the larger cage? I presume these would all work with the 2010 hoods/levers and that the indexing only changed with the latest 12sp?

FYI the frame is a Wilier Izoard 2010 - I haven't got the c/stay length from memory but the total w/base is around 995mm. So it's not mega short but it's got fairly short c/stays - none of which would help make the changing slicker. (FWIW I've notice that changing out the chain way before you'd think you had to change it out on wear grounds makes a real difference to keeping the gears slick).

I'll have to think how much hassle and dosh it is worth to get that little bit lower bottom gear (and before you tell me, it's worth a lot more when you run out of gears than it is sitting on the sofa ;-) )