Bicycle Mechanics - Rear derailleur broken off

Hi everyone,

My rear derailleur broke away from the frame yesterday on my beloved Cannondale H500 and I was wondering if anyone knew what my repair options are. My first thought is that the bike's only good for a fixed gear or single speed conversion, but I'd really rather be able to shift gears back there. I'm including a couple of pics that might be helpful. Any advice appreciated.

The frame's steel, right? And it doesn't use removable dropouts? If this is the case, you could weld one of these to your frame because it would be easy to find the point where the dropout should be due to your own dropouts being intact. That would be my best guess.

I assume the frame is Aluminum (as are most Cannondales) and the pictures show it doesn't have a replaceable dropout. Unless Cannondale can repair it, I think the frame is hosed. The "claw type" derailleur hanger adapter Matt Gaunt suggested will only work with horizontal dropouts and your bike has vertical ones.

The vertical dropouts are also going to make it difficult to convert it to a fixed/single speed bike as you will have to have an exact and fortuitous chainring and cog setup to get the correct chain tension. You can't even fit a "singulator" as they bolt to the derailleur hanger.

Play "Taps" for it and have a respectable period of mourning.

I know the dropouts are wrong, that's why I suggested the welding option. I didn't know the Cannondale was Alu though, that might throw a spanner in the works. If steel, I was thinking of ditching QR altogether and just bolting the wheel on, or to trim the claw so that it does work with vertical dropouts.

your effed

Make it a single speed.

That looks like the same removable hanger they use on the mtn bikes. Just get a new one.

Take the wheel and bag bracket off, and remove that little allen bolt and the hanger will come right off.

http://www.derailleurhanger.com/cannondale.htm

http://www.derailleurhanger.com/cannondale.htm


Thats funny, I thought you said I must be looking at different pictures than everyone else.

I couldn't tell from the pictures at first but you may be correct. If the frame has a replacable hanger, the "cure" is cheap and simple.

It's an aluminum frame with a replaceable hanger. Just replace the hanger, it unbolts. Not a big job.