Spot the difference

If you've been keeping up with our maintenance articles, you'll have noticed a bit in the one about rear mechs that mentions worn jockey wheels and the detrimental effects thereof. Here, thanks to BM staff bloke Cullen, is a timely reminder. Suffering from recalcitrant shifting from an XTR mech, Cullen checked the jockey wheels. The one on the right is one of them. The one on the left is a brand new one. Substantially different, we think you'll agree. You're unlikely to draw blood handling the new one, for a start.

A quick change of jockey wheels and all was well. So if your shifting's all over the place, take a look at your jockeys and if they look anything like this one, it's time for new ones. They're cheaper than a new mech...