Bicycle Mechanics - Front derailleur compatability question (photo and details incl.)

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PDA
Canadian
09-09-10, 12:47 AM
My road bike came with a 9 speed triple, but I recently upgraded to a double crankset. At the moment, the triple front derailleur is still on the bike.

I bought a 9 speed FD upgrade but learned the hard way that I also need to know details like clamp size, style and top or bottom pull.

Here is a photo of my failed purchase on the left compared to my original FD still mounted:

http://img97.imageshack.us/img97/8434/frontderailleurissues.th.jpg (http://img97.imageshack.us/i/frontderailleurissues.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

Am I right to understand that the failed purchase (31.8mm, too small) is a clamp on that cannot be mounted on my bike, and what I need is a braze on 9 speed double top pull, and further, that the size doesn't matter because instead of clamping it to the downtube, I'm only mounting it onto the hardware brazed on to my frame?

cbfight
09-09-10, 12:55 AM
Looks like you've got a bottom pull mounted right now. Your current FD is secured to the seat tube via a braze on adapter clamp. If you remove that clamp, you'll be free to install clamp-on FDs instead. As to the seat tube diameter, that's something you would have to figure out yourself. If that clamp-on adapter is shimano (looks like it), then it should have that measurement stamped on its body. You can also choose to go with another braze on FD, in which case you wouldn't need to worry about clamp size.
Canadian
09-09-10, 01:07 AM
Looks like you've got a bottom pull mounted right now. Your current FD is secured to the seat tube via a braze on adapter clamp. If you remove that clamp, you'll be free to install clamp-on FDs instead. As to the seat tube diameter, that's something you would have to figure out yourself. If that clamp-on adapter is shimano (looks like it), then it should have that measurement stamped on its body. You can also choose to go with another braze on FD, in which case you wouldn't need to worry about clamp size.

:love: Thank you! Your post helped me learn things and save $$. You are cool in my books. :thumb:

cbfight
09-09-10, 01:21 AM
No prob!