Campy rear mech identification
- Thread starter lukesdad
- Start date
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oldgreyandslow
Guru
- Location
- Farnborough
I think long are for triple chainsets and short for doubles, at least my mirage is a triple and the cage is substantially longer than my other compact set, I'll measure it if you like
OP
OP
lukesdad
Guest
That would be very helpfull mine is a 10 speed on a double and I suspect the dealer has got the wrong mech on it.
oldgreyandslow
Guru
- Location
- Farnborough
MartinC
Über Member
- Location
- Cheltenham
Long mech 89.5mm
Medium mech 72.5mm
Short mech 55mm
From 2008 catalogues
Medium mech 72.5mm
Short mech 55mm
From 2008 catalogues
RecordAceFromNew
Swinging Member
- Location
- West London
oldgreyandslow
Guru
- Location
- Farnborough
Will1985
Über Member
- Location
- South Norfolk
It doesn't really matter - the shifting is said to be slightly less responsive but I haven't got a problem with it. Mine is currently mated to a 50/36 chainset and 11/23 cassette - I think I've only ever used a 28t sprocket on it for one ride.
youngoldbloke
The older I get, the faster I used to be ...
My Veloce has a 55mm cage = short. 50x34 with 11-25 gives chain wrap figure of 30 - outside the recommended 27 quoted in the link above. About to change the cassette to 12-27 - will report back, however the existing set-up (as fitted new) runs like clockwork. Can't imagine increasing the CW to 31 will be too testing. Have heard that a short cage will handle 29 cog as long as you avoid big to big. Thought you could only get short and medium flavours anyway
MartinC
Über Member
- Location
- Cheltenham
Having the medium mech will allow you more flexibility in your cassette and chainring options - you could even 'legitimately' run a 13-26 triple if you wanted.
Theoretically the medium mech will give a slower change than a short ('cos it'll be slower in taking up the chain tension) but I think you'd be hard pushed to notice it. The medium mech will be a few grams heavier and maybe not as aesthetically pleasing (depending on taste). If the transnission is disappointing then something else is wrong.
Theoretically the medium mech will give a slower change than a short ('cos it'll be slower in taking up the chain tension) but I think you'd be hard pushed to notice it. The medium mech will be a few grams heavier and maybe not as aesthetically pleasing (depending on taste). If the transnission is disappointing then something else is wrong.
I've run a 13-26 with a 30-42-52 triple using a Campag short mech. Just had to make sure I stayed out of big-big and small-small combinations.
I've also run a 13-29 on a 34-50 compact on a short mech without problems (again keeping out of the big-big combination – which I wouldn't use anyway).
I've also run a 13-29 on a 34-50 compact on a short mech without problems (again keeping out of the big-big combination – which I wouldn't use anyway).
e-rider
Banned member
- Location
- South West
even though you are outside with the 25T it is just about possible - however, the 27T won't work! or not to a satisfactoy level.
youngoldbloke
The older I get, the faster I used to be ...
- that is somewhat at odds with woohoo's experience, it seems! 11 or 12-25 with a 50/34 must be one of the most common set-ups around - as supplied on many new bikes. I am surprised that it is seen as technically 'just about possible' . Anyway I haven't received the cassette yet, so when it arrives, all I can do, in view of the conflicting opinions, is fit it and see what happens ........
MartinC
Über Member
- Location
- Cheltenham
This debate always goes on for ever.
There are 3 issues that determine whether you need a long, short or medium mech. They are:
1. The amount of chain it needs to tension to cope with the difference between the small/small and big/big sprocket. The length of the jockey cage determines this.
2. The top jockey wheel needs to stay at the right distance from the sprockets as it moves across the cassette. This is determined by the hanger and mech geometry and the amount of B tension adjustment you've got.
3. What your own standards are for acceptable.
Three is where things vary the most. Some people will want to stick to the manufacturers spec. These are normally conservative 'cos they allow for the unfavourable combinations of geometry that might occur.
Other people are content to relax 1. 'cos they know that they're never going to use the big/big or small/small combinations. So either they'll allow no chain tension when on the small ring and in small sprockets - noisy and inefficient. Or they won't have enough chain to cope with the big/big combination and risk breaking the transmission if they ever tried to use it. Or they may be lucky and the set up may just work if it's not too far out of spec.
For 2. it's even more subjective. I had a bike with a 9 speed campag transmission with a short mech. In theory this meant I could run 53/39 with up to 26 at the back. When I put a 13-28 cassette on it would just handle the chain wrap but on 39/28 I couldn't adjust the B tension enough to stop the jockey wheel running the chain right against the sprocket - slightly noisy and slight increase in wear. If the rear mech hanger was a mm lower it might've been clear. A lot of people might've been happy to put up with this. I could've taken a link out of the chain and the increased tension would've solved the problem at the cost of making the 53/28 combination break the mech or chain if I tried to use it. For me, at the time, the extra 2 teeth weren't worth it.
The situation is different too if you building a bike for someone else. When it's your own bike you know the compromises and the benefits/downsides - not true if it's someone else.
Putting a 12-27 cassette on a campag short mech set up is only just out of spec and my guess is that that you'd get away with it. I've just got a Miche 12-27 10 speed cassette to put on my Centaur set up - I'm expecting that it'll be perfect, but I might be wrong.
There are 3 issues that determine whether you need a long, short or medium mech. They are:
1. The amount of chain it needs to tension to cope with the difference between the small/small and big/big sprocket. The length of the jockey cage determines this.
2. The top jockey wheel needs to stay at the right distance from the sprockets as it moves across the cassette. This is determined by the hanger and mech geometry and the amount of B tension adjustment you've got.
3. What your own standards are for acceptable.
Three is where things vary the most. Some people will want to stick to the manufacturers spec. These are normally conservative 'cos they allow for the unfavourable combinations of geometry that might occur.
Other people are content to relax 1. 'cos they know that they're never going to use the big/big or small/small combinations. So either they'll allow no chain tension when on the small ring and in small sprockets - noisy and inefficient. Or they won't have enough chain to cope with the big/big combination and risk breaking the transmission if they ever tried to use it. Or they may be lucky and the set up may just work if it's not too far out of spec.
For 2. it's even more subjective. I had a bike with a 9 speed campag transmission with a short mech. In theory this meant I could run 53/39 with up to 26 at the back. When I put a 13-28 cassette on it would just handle the chain wrap but on 39/28 I couldn't adjust the B tension enough to stop the jockey wheel running the chain right against the sprocket - slightly noisy and slight increase in wear. If the rear mech hanger was a mm lower it might've been clear. A lot of people might've been happy to put up with this. I could've taken a link out of the chain and the increased tension would've solved the problem at the cost of making the 53/28 combination break the mech or chain if I tried to use it. For me, at the time, the extra 2 teeth weren't worth it.
The situation is different too if you building a bike for someone else. When it's your own bike you know the compromises and the benefits/downsides - not true if it's someone else.
Putting a 12-27 cassette on a campag short mech set up is only just out of spec and my guess is that that you'd get away with it. I've just got a Miche 12-27 10 speed cassette to put on my Centaur set up - I'm expecting that it'll be perfect, but I might be wrong.
