11 Speed Crankset on 10 speed group

[johnmcinally]

I have an opportunity to buy an 11sp compact crank for my 10sp chorus group. Will this work? Which chain: 10 or 11?

[jazclrint]

Wow, how did I miss this. Sorry. Yes, and 10 speed chain. It will work, but I have no idea how well. I read somewhere that the chainrings are a touch closer but I have no idea if that's true or not. The new Chainrings should improve shifting, however.
Rich

[jp_scruz]

Let's ask the question the other direction...

The official line is that 11 speed requires an 11 speed crank, but I wonder. Campy publishes a lot of rules that are more marketing driven than mechanically true. The new Park tool and Wipperman links actually DO work with their chains, though their published materials say that you can only use their stuff. There are two things that make me doubt the crank story:

1.) In the 2009 Paris-Roubaix, Boonen won using 11 speed with a 10 speed crank. So, you can't use the old crank... except at Paris-Roubaix, because that race is so easy on equipment? To be fair, the photos look like it may have been new rings on 10 speed arms. Still, if you're going to have chain suck on the road, it's at Paris Roubaix.

2.) Lennard Zinn originally posted an article saying that he had been using 11 speed with 10 speed cranks and that it worked great. After someone claimed to have crashed as a result of mixing, he issued a pseudo-retraction that seems like it may have been written by a lawyer. I THINK this means that he mixes with no issues, but doesn't want to be sued for someone else's mistakes or imagination.

So, is the crank a real barrier to switching, or another "rule" that isn't mechanically justified? Has anyone here mixed a 10 speed crank with 11 speed gearing? What happened?

[gattone]

Dear friend,the answer is no! I have already done this but, as reported in the campagnolo technical manual, the width chain for 11s is 5,5mm vs 5,9mm of 10 s and it doesn't work properly. Campagnolo says that there isn't any compatibility. Surely this is the reason!

[alisterdavid]

Ah, my first post. I hope not to offend, but would like an answer to this question as well. Although I have rather made up my mind on this one. So if anyone has tried this please speak now.

Having just bought the last 10 speed groupset avalible at pre 2007 prices I am awaiting the arrival of a chorus package with 10s ST chainset, Square taper n' all. Looking to change the c/set to an Ultra torque 11 speed as they are far more available.

Here goes. 11s uses a narrower chain (as remarked previously). This is to allow for the closer sprockets on the cassette. While only a fraction of a mm, never the less, a significant amount for an indexed system that has been crammed into a set space, moreso over the past few years. (8 and 9 speed freehubs are the same size, the increase was made up from 7 speed systems. at which time the dropouts of road bikes were seperated by a further 5mm [ reference required ] and the hub witdth increased accordingly). All well and good to say don't run a 10 speed chain on an 11 speed system for this reason.
However at the front end (chainset) it is a different matter. Campag does not use indexed front shifting (they utilise a 'micro ratchet' etc.) therefor allowing a raft of adjustment to both get the chain onto the correct ring and keep it there. This eliminates the problem of spacing between chainrings and the use of different speed systems or indeed double/tripple chainsets. What about the narrower chain. Yes it should not fit over the teeth of an older system (11 s chain on a 10/9/8 chainring) This I would think to be a problem (chain suck, split links, cracked rollers, ...) But surley the wider chain will breaze onto the newer chainrings. Not so loose as to be a problem of any kind. Unless the pitch of the chain is different (distance between the pins) it should work with the newer chainset without fault. The chainline is the same on the new systems as the old, so drive angles from chainrings to cassette are the same (ie chain won't be snagging bigger rings any more than the correct combination would). the 0.4 mm that the chain rings may have been mover together is not going to make an apreciable difference to shifting between a 39/53 or 34/50 with a slightly wider chain. The chain still has to be pushed onto the ramps to make the shift/ pulled off the ring to make the drop.

I'll be sure to let you all know as soon as I have the kit.

[Mick F]

I have no experience of 11sp, but loads of 10sp and 9sp.

Here's a thought, a 9sp chain works on a 10sp system, I know because I've proved it.
Therefore a 10sp chain will work on an 11sp system. Same argument, surely?