5

I bought a new frame and put my old Campagnolo Racing T components on it. The seat tube has a diameter of 35mm and I use the Campagnolo 35mm clamp for the Racing T derailleur.

The problem is the derailleur can't push the chain to the small gear because a part of the derailleur touches the seat tube.

Is the frame incompatible with a 3 speed crank or do I just need a compatible derailleur for frames with a wider seat tube, maybe the ATHENA Tripple?

Parts

  • Frame: BULLS Desert Falcon, Seat Tube 35mm
  • Crank: Campagnolo Athena 11s
  • Derailleur: Campagnolo Racing T
  • Bottom Bracket: Campagnolo BB90 Power Torque

Images:

  • Derailleur touching the frame: Derailleur touching the frame

  • Crank: Crank

  • 1
    I've never done it but I would think some type of spacer between the chainring and the BB could give you a bit more clearance to let the front derailleur push in further. – ebrohman May 28 '15 at 20:15
  • I was thinking this too, or maybe twisting the derailleur a little to knock the chain earlier? The top picture looks like it is slightly twisted out compared to the outer sprocket, but can't tell for sure. – BillyNair May 31 '15 at 23:46
  • The BB does not have enough offset. – Daniel R Hicks Jun 6 '15 at 22:16
2

The chainwheel does not sit at the correct chain line is the answer.

The most common cause is that you have an axle length shorter/longer than the ideal chain line. In this case, you have a shorter axle length.

Did you add another chainring into your crankset? If the answer is yes, you will need to tweak around: either adding spacer (not recommended) or find a compatible front derailleurs (better get to the LBS for trial/error fitting). If the answer is no, then it will be the frame that cause you the problems, albeit unlikely. I always solve this problems by finding a correct axle length for my crankset.

You can refer to this article for more information, from Lord Sheldon. http://www.sheldonbrown.com/chainline.html

| improve this answer | |
1

Replacing the Racing T derailleur with the Athena 11s derailleur fixed the issue. The racing T derailleur seams to don't work with the 35mm Campagnolo clamp. Or generally don't work with frames wider than 28mm.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.