Switch from 12-25 to 13-29 0- do I need longer chain?

FoldingJoe

Guys,

Got the Dartmoor Classic on Sunday and I've not been able to get as much training in as I had hoped, so decided to change my cassette to a 13-29 from a 12-25.

I've heard this should be OK on a short cage rear mech on Campag Veloce, but do I need to change the length of my chain?

Running 50/34 up front.

Cheers,
FJ

rolf_f

I run a specific chain for that cassette with two extra links irrc (ie a single pair). It's a Connex one so I can tell it apart from the Campags I use on the 11-25s.

FoldingJoe

Rolf,

Do you have a internet link to such a thing?

Thanks,
FJ

rolf_f

It was on offer at Chain Reaction for £12 (actually Mavic branded but apparently a Connex chain). No longer stocked but I found it here and still a decent price -
http://www.slanecycles.com/mavic-10-spe ... livery=222

Only £3 more than I paid a couple of years back (here at £14.99) - I may get a spare. I prefer the Campag chains but really it's not bad and it comes with a very nice quicklink.

FoldingJoe

Rolf, what rear mech do you have, short or long?

I'm worried that my short mech won't be able to cope with a 50/34 and 13/29.

Cheers,
FJ

rolf_f

Short. And I suspect it might cope with a tooth more if there was a cassette to try it on.

There is some variation in what various years of Campag rear mech manual tell you is possible (one ex member seemed to delight in telling folk that a Campag short cage couldn't handle a 13-29 in the large large combination despite myself and others pointing out that we run such a setup and have no problem crossing the chain to large large!) but, certainly now, the manual says 13-29 is OK for short. My mechs are not current and do fine - it's worth noting that Campag have for several years done 13-29s in various different groupset specs yet only Veloce (irrc) has been available in anything other than short in recent times. In other words, if 13-29 doesn't work with short cage, why would Campag make a cassette for which they have no matching rear mech?

You may need to adjust the screw that gives clearance between the mech and largest sprocket but I don't even have to do that.

FoldingJoe

Sweet, thanks for getting back to me.

rolf_f

FoldingJoe wrote:

Sweet, thanks for getting back to me.

No worries - but do make sure it all works properly before the big ride!

FoldingJoe

Thanks for all the help.

Fitted my 13-29 on Saturday, and all was fine Sunday for the DC. Still got cramp!!