Do I need a Compact front mech?

[slow down]

Thinking of switching one of my bikes to a compact chainset, currently Campag Veloce 39/53 with a 12-25 cassette. If I swap to a 50/34, do I really need a new front mech (or a medium cage rear mech for that matter), or will the standard mechs cope?

 

[TheDoctor]

Received wisdom is that the standard mech works fine, but the compact one is a little smoother. Can't speak for the rear mech, but you're only asking it to wrap an extra few links of chain, so I'd try it and see.

I expect someone who's actually done this with Campag will be along soon. I've only done it on Shimano (taking a 52/42/30 set to 48/38/24).

 

[Dave Davenport]

Shouldn't be a problem using existing mechs.

 

[spandex]

yer it will all work but you might need to move the f mech down by ? 4, 5 mil if it rubs.

 

[Smokin Joe]

I've just switched from using a mid-nineties 105 front mech to the new Campag combined thingy on a Centaur compact.

Bugger all difference.

 

[fossyant]

Front mechs are usually same except those for 3 chain rings, then there might be a difference - i.e. more travel.

You'll need to move the mech up or down the down tube so there is about 3mm clearance of the cage to biggest chain ring.

 

[arranandy]

Shouldn't be a problem. I did exactly the same and all I had to do - apart from fitting compact chainset - was reposition front mech slightly and take a couple of links out of the chain.

 

[Membrane]

I've only done it on Shimano (taking a 52/42/30 set to 48/38/24).

Which Shimano range offers a 48/38/24?

 

[TheDoctor]

Which Shimano range offers a 48/38/24?

Any of them once you've changed all the rings!
It was actually a Sora. And yes, I did change all the rings. It's not a facetious reply.

 

[Membrane]

Any of them once you've changed all the rings!
It was actually a Sora. And yes, I did change all the rings. It's not a facetious reply.

Ah, right. I was wondering because that 24T difference falls outside of Shimano specifications (they are specified up to a 22T difference).

 

[TheDoctor]

Indeed. I actually wanted a 26T inner ring, but the LBS had run out. I'm using a 13-26 cassette, and a 25" bottom gear struck me as being a little overkill. Having said that, it came in handy in the alps and North Wales.