Hello, I'm looking for some advice about chainrings. I replaced my chain and cassette the other day, thinking the chainrings look alright and would be more hardwearing I left them as they were, however I was getting a lot of chain slip under load, setting off in medium/high gear etc. which makes me think they need replacing too. First of all, after 3000 miles, is it likely that the chainrings need replacing or could I have set something up wrongly when I've made the changes? They don't look too bad, but then again you can tell they've been well-used.
If they do need replacing, here's my other questions:
(I have a 105 Compact 34/50.)
a) Can i increase the teeth on the large ring without having to change the deraileur, length of chain etc? and if so, by how much?
b) are all manufacturer's chainrings compatible with each other? I realise that Campag, SRam probably won't like Shimano, but what about FSA, stronglight, TA etc...?
c) Does the chainring I buy need to be compact-specific, many are labelled 'double'. Would that work?
Thanks in advance for any advice, as with buying many types of bike parts every seller seems to be a minefield of words with little explanation.