Jockey wheels

[Domus]

After some clicking from my 105 crank on my three day Cheshire tourist week, It is time for a little TLC before my France / Belgium / Netherlands tour in early June. BB removed and it is a gritty horrible mess after two tours, several night rides and use as my winter bike, chain is in good nick, jockey wheels removed and what a mess. The bottom one (tension?) has worn through the retaining screw almost half way. I assume there should be a bush in there as in the top one, if so it is no more. It must be grit that has acted as an abrasive medium over the winter to cause the plastic wheel to grind away the steel. Amazing the damage that has occurred.

 

[Ajax Bay]

Think we need pictures to allow full empathy.
BB and the jockey wheel screw.

 

[Domus]

Here you go, nasty

 

[Ajax Bay]

That screw's extraordinary! I guess the flat created was facing rear, given the force from the cage to generate tension in the return section of the chain. But the screw is steel, I think. What material in contact with it is harder? (Not at home so can't 'play'.)
I can't think of a way to reduce the likelihood of your BB degenerating to its "gritty horrible mess". It's so exposed it's just bound to just happen. Any ideas?

 

[fossyant]

I won't ask how you didn't notice the jockey being so bad. It would flop about if the bush has gone !