Convert 7speed Campagnolo to Compact

[plasma2873]

Is it possible to cost effectively convert a 1982 7speed Campagnolo bike to a compact- 50/34, 12-28 or am I biting off more than I can chew.

My friend has asked me if he can convert his old Pennine 531 Audax bike, but he wants to keep it Campagnolo with downtube shifters if possible.

Thanks,

Stuart

 

[hamster]

Simple, get a Spa Cycles Stronglight Impact double plus bottom bracket.
https://spacycles.co.uk/m2b0s109p45/STR ... act-Double
Cost around £60.

You will have to lower the front mech a little to bring it closer to the chain.

 

[pigman]

Re:

What might be a problem is if you're using an old style campag mech, whether it will cope with the 28 cog and be able to take up the slack. You may need to source a campag rally mech

 

[hamster]

@pigman I think you are right, good point, which I hadn't considered. You can just about squeeze them to a 29T total cog difference (with things a bit rattly at the big-big extreme) so a 47T is probably the largest at the front combined with a 28 at the back.
However that will also depend on the length of the mech hanger, the rear derailleur may hit the sprocket. So a mech dropper may also be needed.

 

[legrandefromage]

Personally I think it will be fine if the 28 34 is only used for climbing. I run very short cage mechs with 28t cassette and 52/53t and 50t triples, the chain can sometimes be a bit flappy if I dont do it right

 

[pigman]

Re:

When I tried cyclo-x back in the 80s, I used a nuovo record mech, but had difficulty using 42x28. The top Jockey wheel would foul the 28 sprocket. I cured it in the end by making a washer with a tab that pushed the mech back from the stop built into the dropout

If the OP has the original nuovo record/ super record, which effectively only have 1 chain- tension pivot, I think there will be difficulties with a 28 cog and a compact chainset

 

[hamster]

That's exactly the problem I had with a Record rear - and it's solved by a mech dropper, a couple of quid on eBay.

 

[cromoman]

Re:

I concur with pigman and hamster.

The best I've had with Nuovo Record is 50:36 with 14:26 at the back.

The problem is that if you have sufficient chain length to clear big ring / big sprocket, then when you put it in the small ring, there isn't enough chain tension to bring the cage forward and consequently the jockey wheel will foul the sprocket.

A smaller big ring allowing for a shorter chain may help - perhaps 46:34 would work ok.

If it's friction levers, then you could replace the rear mech. I've had 50:35 with 14:28 on a Victory setup with not problem at all.

 

[legrandefromage]

Yes, I've been using Shimano too long

You could always change the rear mech to 'Rally' style

I think this was a Nuovo Record with the longer cage

*Plus it shows that theres not a lot of room in a Campagnolo front mech to go low - a more modern triple may sort that, if...