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Front derailleur - how to increase travel?
#1
How do I increase the travel of the front derailleur?

I had to replace the bottom bracket. The new spindle is longer than the one I replaced. Now, I can't get sufficient travel to move the chain to the outside chainring (of a double).

I've backed the limit screw out as far as it will go. The arm of the derailleur hits the body of the derailleur itself. There is no more room to give.

Do I need to replace the derailleur? If so, what kind of information do I need to find a derailleur with sufficient travel.

Thanks,
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#2
I suspect you'll probably have to find a shorter spindle. I assume some derailleurs have slightly more travel than others, but I don't know of any way to determine it other than trial and error.

If your BB is a three piece cup and spindle type, you might be able to just put it in the other way. A lot of spindles are longer on the drive side so reversing it would bring the crank closer to the frame. It would push your left leg out farther which isn't ideal, but not that big a deal.
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#3
Dave has it covered.

You may be able to find a MTB front derailleur intended for a triple that will go far enough out, but most are limited to 48T is the biggest chain ring.

There is a reason that crank sets suggest a certain length of BB axle......

If you have a "sealed" bottom bracket, you'll need to get another one, the correct length.
http://www.amazon.com/Shimano-BB-UN54-Square-Bottom-Bracket/dp/B0014C4G58/

Here is an example of what Dave mentioned:
http://www.amazon.com/Pyramid-Bottom-Bracket-Axle-Type/dp/B000BMNQVW/
they are available in different lengths and offsets.
Nigel
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