Campag conundrum

[Meejoir]

I'm currently making a start to my second refurb and I've accumulated a bunch of relatively elderly and used but well loved Campag components.

The problem I've got is that I want to fit a triple chainset, a Veloce 52/42/30, as this will help me with my personal nemesis of climbing hills. I have a 9 speed Mirage rear mech to go with the corresponding Mirage shifters, but I have no idea if the rear mech is a short or medium cage.

Firstly, does anyone know how I can tell what size cage it is, and secondly does it matter? Can you run a triple with a short cage? Although I haven't acquired a cassette yet, I'd assume a 12/28 would be most suitable (the more teeth the better).

Please forgive my ignorance, it's all new to me! Any help and advice would be greatly appreciated.

 

[mattsccm]

That chainset will run with a short mech. I set one up last week like that and its fine but won't cope with the slack chain on the 3 smallest sprockets on an 8 speed system. No great loss.
Plenty of medium mechs out there for not a lot. They are fine. Even Comp or Race triple mechs are dead cheap on ebay. they are not what would be called long.

 

[lewisfoto]

The issue is the range in gearing from the smallest to the largest more than the number of gears. If you have a model name and number for your mech then determining the total range should be easy. (searching online) You may well start on Velobase...

 

[Penfold6290]

From what I can gather Campag RDs come in three cage lengths; 55, 72.5 and 89 mm measured from the center of the upper jockey wheel to the center of the lower jockey wheel. 55 mm cages have a chain wrap value of 27; 72.5 cages have a CW of 36 while 89mm long cages have a chain wrap value of 39.

Your suggested setup 30/42/52 and 12-28 has a chain wrap of 38 ((52-30) + (28-12)) which would suggest you ought to use a long cage to cope with the full amount of chain slack when using the bottom gear. A medium cage would probably just about cope though if you're careful.

Martin

 

[Meejoir]

Thanks guys, I really appreciate the response. I'll take some measurements tomorrow and see exactly how long the cage is.

 

[Newman8]

You should use a long cage - but not only that - a triple specific front mech & a different bottom bracket. If memory serves, my Veloce square taper bb for double is 111.5mm but for triple it would have been 115mm.

Shifters are ok though. Rear (RH) is indexed, but LH is friction so ok with 3. (although I've heard newer models differ).

12-28 with 30-42-52 sounds like good combo. You get really low hill gears without losing your fastest (52F-12R) gear. With a 30t front you could prob even use a smaller rear cassette.

I've tried quite a few different combos over last year or two (inc triple) & have currently settled on a standard 39-53 front but with a big 13-29 on back. I could get very good shifting with a short cage with careful set-up, but I actually find the long cage copes with the full range slightly better. I use the full range on every trip - I live at the foot of a nice 20% climb & rides round here are all short sharp climbs with quick scary descents & not much flat in between!

 

[Newman8]

BTW
I don't think it matters what 'speed' RD you buy. It's your shifters (indexing) & cassette (spacing) that need to match one another.
Maybe someone can confirm that 100%?

 

[Meejoir]

That's interesting, as I've always thought my options were limited as far as RDs go as 10 and 11 speed seem readily available but it's getting more difficult to source a 9 speed.

 

[hamster]

Firstly it depends on the year of your shifters. If pre-2001 you need an earlier type mech as the pull per click is different from 2001 onwards.

Secondly, you can run a 111mm BB on some frames - my Litespeed runs a Centaur triple happily with a 32mm seat tube and 11mm BB. Some Alu frames will not though.

I have just about got away with a 30/39/48 on a short cage Chorus 1994 rear mech and 12-23 cassette. I mean just though. It's very rattly in big-big, but does engage safely which is important. Running a Racing T rear I happily can run a 24T difference at the front with the 12-23, which I make as 35T total, within the medium cage 36T limit.

Don't adopt any setup which does not allow big-big. If you inadvertently engage it (such as having just avoided the psychopath in the black Range Rover) you risk stuffing the rear mech into the wheel. I know this.

 

[pigman]

BTW
I don't think it matters what 'speed' RD you buy. It's your shifters (indexing) & cassette (spacing) that need to match one another.
Maybe someone can confirm that 100%?

in terms of lateral shifting and indexing you are right.

the difficulty is that a short cage mech cannot absorb the chainslack of going from say 52x28 to 30x13. A long arm mech can do this.
You could in theory get away without the longarm mech, like someone has suggested run it so thay when its in small/small, the chain hangs like a cow's underbelly. I've done this myself and its a manageable compromise. However don't compromise the other way, so that small/small is ok, but big/big is not. I've seen this done on a mates bike. As we rode back from dover (we went to watch the tour in dunkirk) up the hill from folkstone, he suddenly needed big/big, forgot this wasn't possible and the rear mech exploded under the strain. We strapped his bike up single gear and he somehow made it.