Campagnolo Chorus 11-25 to 11-29 upgrade

timujink

Hi,

I have just bought a campag chorus 12/29 cassette, currently riding 12/29 with a 34/50 compact.

My question is, would I need to add links to the standard chorus chain?

Has anyone a similar experience?

Thanks,
Timujin

bondurant

This is a good guide to see whether your current chain length is going to be long enough for your new cassette. At least, I think that's what you're asking?
http://www.parktool.com/blog/repair-help/chain-length-sizing

drlodge

If you already have the cassette then just try it out - try moving from 34-12 to the 50-29 combination and see if the chain is long enough. Do this with the bike on a stand (not riding it) and move the pedals SLOWLY in case the chain ain't long enough.

A quick way to tell is with the chain on the 34-12 combination, could the RD take up any additional capacity? If not, then the chan is as long as it can be, and you should be fine. If not, then the chain is possibly too short. This is assuming you have a Campy 11sp RD

Monty Dog

Highly likely on the basis that most chains are sized using the big ring + big sprocket basis, so you're probably in need of 2 extra links. Riding with too-short a chain is a rapid way of trashing a transmission as the rear mech gets hooked on the big sprocket, taking out the spokes on the drive side and sometimes snapping the rear mech hanger and seatstay too.

timujink

Thanks Guys!!!!

timujink

drlodge wrote:

If you already have the cassette then just try it out - try moving from 34-12 to the 50-29 combination and see if the chain is long enough. Do this with the bike on a stand (not riding it) and move the pedals SLOWLY in case the chain ain't long enough.

A quick way to tell is with the chain on the 34-12 combination, could the RD take up any additional capacity? If not, then the chan is as long as it can be, and you should be fine. If not, then the chain is possibly too short. This is assuming you have a Campy 11sp RD

Yep, I have a campy full setup.... ill try it tonight at the lbs....

AlahDamIt

Just done this my self, I needed a new chain. I managed to use the extra from the new chain to extend the old chain (old chain a only 10miles old) so I now have a spare

drlodge

Monty Dog wrote:

Highly likely on the basis that most chains are sized using the big ring + big sprocket basis, so you're probably in need of 2 extra links. Riding with too-short a chain is a rapid way of trashing a transmission as the rear mech gets hooked on the big sprocket, taking out the spokes on the drive side and sometimes snapping the rear mech hanger and seatstay too.

If the chain was sized on the basis of large-large then I agree, it may be too short. However if was sized on the basis of small-small (which is how I size my chains) then it will be the correct length. I guess with the OP's setup, the chain will either be the correct length, or 2 links too short.

keef66

drlodge wrote:

Monty Dog wrote:

Highly likely on the basis that most chains are sized using the big ring + big sprocket basis, so you're probably in need of 2 extra links. Riding with too-short a chain is a rapid way of trashing a transmission as the rear mech gets hooked on the big sprocket, taking out the spokes on the drive side and sometimes snapping the rear mech hanger and seatstay too.

If the chain was sized on the basis of large-large then I agree, it may be too short. However if was sized on the basis of small-small (which is how I size my chains) then it will be the correct length. I guess with the OP's setup, the chain will either be the correct length, or 2 links too short.

If you size your chain in small / small, what then happens if the large / large combo pulls the mech into the sprocket?

timujink

My chain was standard and was loose on the 34 - 12 so boom managed to change the cassette perfect, no extra links.. now for a wkd of climbing!!!!

drlodge

keef66 wrote:

If you size your chain in small / small, what then happens if the large / large combo pulls the mech into the sprocket?

Don't know what you mean - if the chain is sized for length on small/small, the its as long as it can possibly be. Or are you referring to the "B screw" adjustment?

canoas

Heading for the Alps, friend has given me some unused Rotor 3D cranks 172.5mm with noQ rings , he's going down to 170mm. I run Campy SR. Currently with a 11-25.

If I upgrade to Chorus to a 11-29 (I love Chorus cassette/chain best durability!)

A) Will my 2011, 11 speed Campy SR rear mech be long enough? 52-36
What will be the gear ratio on the 29 (52-36), will it be similar to a 34/27?

Thanks

drlodge

canoas wrote:

Heading for the Alps, friend has given me some unused Rotor 3D cranks 172.5mm with noQ rings , he's going down to 170mm. I run Campy SR. Currently with a 11-25.

If I upgrade to Chorus to a 11-29 (I love Chorus cassette/chain best durability!)

A) Will my 2011, 11 speed Campy SR rear mech be long enough? 52-36
What will be the gear ratio on the 29 (52-36), will it be similar to a 34/27?

Thanks

Should be fine, not 100% sure if 2011 Campag was designed to run with 29 cassette but I would hazard a guess it will still work. Just double check chain length/take up on big-big. The 29 chorus cassette is 12-29 not 11-29. 36x29 is about the same as 34x"27.3" so a slightly lower gear than what you have now.

thegreatdivide

drlodge wrote:

canoas wrote:

Heading for the Alps, friend has given me some unused Rotor 3D cranks 172.5mm with noQ rings , he's going down to 170mm. I run Campy SR. Currently with a 11-25.

If I upgrade to Chorus to a 11-29 (I love Chorus cassette/chain best durability!)

A) Will my 2011, 11 speed Campy SR rear mech be long enough? 52-36
What will be the gear ratio on the 29 (52-36), will it be similar to a 34/27?

Thanks

Should be fine, not 100% sure if 2011 Campag was designed to run with 29 cassette but I would hazard a guess it will still work. Just double check chain length/take up on big-big. The 29 chorus cassette is 12-29 not 11-29. 36x29 is about the same as 34x"27.3" so a slightly lower gear than what you have now.

[Edit] It was. The 12/29 cassette for 11-speed has been out for a while now and Campagnolo standardised cage length in 2010 on all Chorus/R/SR 11-speed rear mechs. The 11/29 came out at the same time as the new 4-arm groupsets but I run an 11/29 on my 2011 SR set up (34/12 rings) with no issues