GGDub

I'm in the midst of converting my old Jake into a triple drivetrain and have come across a pickle of a problem. The seat tube is 34.9 mm and as such I bought a braze-on triple front derailleur that fits the oversized clamp I already had.

However, the problem is, when dropping the derailleur into the granny gear (low) position, the hinge arm of the derailleur contacts the seat tube which does not allow the derailleur to move far enough inwards to force the chain to drop into the granny.

The only solution I could come up with, is finding a spacer that fits between the derailleur and the clamp groove in order to set the derailleur slighty farther back from the seat tube. I have not been able to find any part like this anywhere.

Anyone else ever have this issue and does such a shaped spaced exist? Or alternatively, is this a chainline problem with my crankset being too close to the frame?

HillRider

It sounds like you need a longer bottom bracket spindle. Did you convert the double crank to a triple but keep the old bottom bracket?

Terrapin Tim

Even with the correct triple BB i had similar problems on my Felt road bike. Another BFer suggested a spacer in the BB to move the chainline out until the fd worked propoerly but had adequate clearance to avoid the tube... worked like a charm.... but you have to start with the correct BB length

GGDub

Awesome, thanks for the responses. I didn't even factor in a new bb when I was doing this, but now it makes perfect sense since I've come across triple BB's in the past but completely forgot about them when I started this conversion.