Broken jockey wheel

Chelloveck

So...I was out on a ride recently and one of the jockey wheels fractured, with a chunk of the jockey wheel braking away. I don't know why. I didn't crash and I wasn't hammering it, but the bike has clocked 550 miles in 6 months. I have a Voodoo Hoodoo and the rear derailleur is a 9 speed Shimano Alivia RD-M430. The rest of the derailleur and chain is fine.

Surprisingly, none of my local bike shops have the part in stock and Halfords want to charge me for a full new derailleur. So, I've been thinking of doing it myself, but I am a bike maintenance novice and there is precious little information online. How easy is it to do if I just bought the jockey wheels online?

Is it tricky to install and then reset the rear derailleur? And given the price of the jockey wheels themselves (around 10 quid), is it worth plumping for a whole new derailleur system (mine is worth about 35 quid)? Finally, any suggestions on the type of jockey wheel? I can't afford ceramic ones but I don't know whether to go plastic, alloy or some other metal.

Please help a fellow MTB'er out because this problem has grounded me in the height of summer! Cheers.

cooldad

Top or bottom wheel?
Bottom is really easy, just undo the bolt, put new wheel in (with the chain wrapped around obviously) do bolt up. Top is easy enough, just take the side plate off totally, no need to take the mech off if you don't want to.
I would look for TACX or BBB Rollerboys. Both good, both under £10 a pair on Ebay.
http://www.ebay.co.uk/itm/TACX-T4050-JO ... 3cd1ada217

cooldad

ps Read Parktools for how to do everything. 'Read this first' below.

The Rookie

And it's AliviO.....

CRC do the jockets for a few quid delivered.

Chelloveck

Cheers for that. It's the top jockey wheel, but I'm going to order one in and try it myself.