Rear derailleur help needed!!

[DazTheDJ]

I was riding out on Saturday and my rear derailleur came apart and I lost a jockey wheel and a bolt. I'm trying to find replacements but I'm not very knowledgeable. I've no idea if I have a short, medium or long cage or know how I can figure it out. Also I'm not sure if the bolts are generic or not. I don't really want to pay for a new derailleur as I'm not exactly flush at the minute. I'm doing Ironman UK in 20 days so need to be sorted ASAP. It's a Campagnolo Mirage 9 speed derailleur.

Thanks in advance for any info!

 

[PpPete]

Getting a suitable jockey wheel shouldn't be an issue.
For some reason which more knowledgeable folks might be able to advise on Campag use a different number of teeth on their jockey wheels than Shimano.
Personally I've never understood why - the chain is always the same pitch. And the jockey wheel will be the same across all cage lengths.
Tacx is a name that springs to mind for aftermarket jockey wheels.

However I suspect that getting a replacement bolt might be much more of an issue.

I think I'd start by removing the other jockey wheel and it's bolt, moving it in to the pace of the missing one, to see if all fits, then you have something to work on in the way of measurements.

 

[Soltydog]

Even shimano use different size jockey wheels. Not sure if its dependant on number of gears, groupset, or possibly both. LBS should be able to advise