I am building up my new Cervelo P2C. When the chain is in the small (39t) ring up front, and in the 14t or 13t in the back, the chain hits the large dura ace chainring and has quite a bit of friction. What am I missing here? The chain is not completely cross-chained (not 39/11), I should be able to ride my 14t and 13t in back while in the small chainring. Any help would be appreciated. Thanks! Dan

Check your front DR alignment (horizontal) and clearance (vertical) off the big chain ring.

 Hi, can you take a picture.... to get a better idea, i got my p2c since a year now with campy coponents , 12-25 cassette & FSA megaexo  no complain about it

It hits when the chain comes off the bottom of the crank, not at the top at the front derailleur. The f. derailleur alignment and height is correct, as is the rear derailleur adjustment. Any ideas why the chain is hitting near the bottom of the crankset when it comes off of the small chainring? All the parts are new Dura Ace so nothing is damaged, etc. Thank you in advance, Dan

 i think the probl is with cassette, if your are using 14-13t at the end, may run very clser to seat tray.   try to switch to 12t or 11t to allow enough clearance and don't  forget to adjust the rear Der.

good look!!!

 

The cassette is a standard shimano Ultegra 11-23. So the 11 rubs obviously but this is a cross-chain gear that shouldn't be ridden anyways. The problem is that the chain still hits the large chainring even when in the 14t, which is the 4th gear up.

is it hitting the chainring as you state, or is it hitting the front cage.  take it to a shop, should only take a good shop a short while to figure it out, in the mean time you could be riding instead of messing with it.  You may get rubbing noise in the first 3 or 4 on the cassette your bike has a short chainstay and amplifies the chain angle.

It is hitting the large chainring as the chain comes off the small chainring near the bottom of the crank, not the front derailleur cage. This could be because of the chain angle as you state. I work in a bike shop, my co-workers couldn't figure this out and I'm wondering if anyone has any other ideas, or if this is a common problem.