Bicycle Mechanics - wrong front derailleur

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.



PDA

View Full Version : wrong front derailleur

danguskhan
04-15-12, 02:20 PM
I accidentally bought the wrong front derailleur for a 2x7 to 2x10 conversion I am doing on my 1994 cannondale r400. I got the 105 fd 5700 with some other things I bought off of craigslist. However I got a top pull 34.9 and I need a bottom pull 31.8

Will it work at all to use my old 2x7 derailleur while I wait for the other one to come or is it not going to work at all?

danguskhan
04-15-12, 02:54 PM
Actually I was wrong, they are both bottom pull. I might actually have a spacer that will let me use this derailleur with my smaller tube. However, if that doesnt work can I use the old rsx 2x7 with my 2x10 or will it not work at all?

Thanks
Retro Grouch
04-15-12, 04:16 PM
My philosophy:
If I'm buying parts I'll hold out for the correct matching thing.
If I already own parts I'll bolt up what I have and see if I can make it work.

You're in the second category. I'm about 90% confident that your existing derailleur will work. If you're using bar end shifters or some other friction thing I'd bump that up to about 98%.

Jeff Wills
04-15-12, 06:38 PM
My philosophy:
If I'm buying parts I'll hold out for the correct matching thing.
If I already own parts I'll bolt up what I have and see if I can make it work.

You're in the second category. I'm about 90% confident that your existing derailleur will work. If you're using bar end shifters or some other friction thing I'd bump that up to about 98%.

+1. If you want to try the 10-speed front derailleur, use a short piece of PVC pipe to make a shim. I did this when I bought the wrong size clamp (like you did) and it worked fine for years.