Bicycle Mechanics - Replace Rear Derailleur--how to choose?

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rosstrek82
05-29-06, 09:17 AM
I have a trek 400 (1982 model). The rear derailleur is a shimano rd-2505. The front sproket is 28-45-50, and the rear sproket it 13-14-17-20-24-28. I can't find an rd-2505. How do I figure out what to replace it with using the read derailleurs that are currently available? Thanks.

Retro Grouch
05-29-06, 09:24 AM
Any Shimano rear derailleur that has a long arm will work.
robhunterx
05-29-06, 10:04 AM
Pay attention to how this RD attaches to the frame and get any model (Shimano or Sram) with a long cage that attaches in the same manner.

Banzai
05-29-06, 11:53 AM
Any Shimano rear derailleur that has a long arm will work.

At six speeds in that gear range, I would say ANY would work. That's well within the capability of all of their "road" derailleurs, and even more inside the capability of their "mountain" derailleurs.

The main issue, as stated, will be the attachment points.

An Acera RD, if the attachments work, will hook you up for pretty cheap, and be of enough quality to be reliable as well. After that they get "quieter", lighter, and fancier. A Sora will also hook you up pretty cheap in the "road" category.

Be mindful of the attachment mechanism.