Tech question. do i need to change fd to run compact?

[cmg]

went to a compact crank(50-34) 11 spd on my cobbled campy 10 spd. using a chorus 10 spd front derailluer. i'm having trouble setting it up. hits the back of the crank on the big ring. do i need to go to different front derailluer?

[Hindmost]

?? The front derailleur shouldn't see much difference between a 50/34 and a 53/39, say. Are you satisfied with the derailleur height, orientation and outer limit adjustment?

[Mark McM]

went to a compact crank(50-34) 11 spd on my cobbled campy 10 spd. using a chorus 10 spd front derailluer. i'm having trouble setting it up. hits the back of the crank on the big ring. do i need to go to different front derailluer?

You shouldn't need a new derailleur. I've run compacts with both 10spd and 11spd Campagnolo standard derailleurs without a problem.

Hitting the back of the crank arm means the limit stop is set too far out. If you can't adjust the limit stop without the derailleur rubbing the crank or the chain suggests that either a poor angular adjustment of the derailleur cage, or there is a very poor chainline between the cassette and crank.

[mktng]

What set up do you have? Take a picture.
However. Sounds like your limits need to be readjusted. Bring the FD back in a bit. Just enough not to rub the cranks.

[Ken Robb]

You shouldn't need a new derailleur. I've run compacts with both 10spd and 11spd Campagnolo standard derailleurs without a problem.

Hitting the back of the crank arm means the limit stop is set too far out. If you can't adjust the limit stop without the derailleur rubbing the crank or the chain suggests that either a poor angular adjustment of the derailleur cage, or there is a very poor chainline between the cassette and crank.

I agree. I ran 50-34 with derailer that I had previously used with 52/39 and I ran a Racing Triple for 52-42-30 cranks with 48-38-28 rings too. None of the bikes had brazed-on derailers though so their heights were very easily adjusted. I can imagine a bike with brazed-on derailer MIGHT not get low enough to shift smaller rings well but I don't know for sure.

[rustychisel]

Have your exact setup, 10 speed Chorus now with square taper 50x34 on front. You don't need a new derailleur, but if something isn't allowing you to setup with correct clearances then THAT is the problem.

[ChainNoise]

Look for a comprehensive front derailleur setup DIY video on YouTube for your specific detailleur. This will walk you through the process start to finish to getting a clean, crisp front ring shift.

[oldpotatoe]

went to a compact crank(50-34) 11 spd on my cobbled campy 10 spd. using a chorus 10 spd front derailluer. i'm having trouble setting it up. hits the back of the crank on the big ring. do i need to go to different front derailluer?

No..FD too much tail out or outboard limit screw too far out.If you having trouble getting the chain onto the big ring the fder 'may' be too high or the seat tube angle is steep, raising the tail and the 'bump' on the inside of the front der where it doesn't contact the chain at the proper place on the inside of the front der.

There was 'compact' front ders but they didn't work any better than 'standard', then Campag dropped them. Shimano never had one..they just added 2T 'range' to their printed fder 'capacity'...

[ultraman6970]

IMO it should work. Re adjust the thing from the beginning. Back screw, front screw and height, but IMO even if you did not change the height it should work ok.

[unterhausen]

50 should be fine with a regular FD. I have found that with a 46 tooth chainring, the CX70 works better.

[cmg]

Raised the FD to get about 5mm clearance from the chain ring and adjusted the screws both out and in. works better can get on to 50 12 without hitting the inside crank. It's a super record crank and it really showed the amount of stretch in the chain. you can lift the chain off the ring at the 3 o'clock position. will get a new one. thanks