How low can you go?

[Benthedoon]

This may be a ridiculous question but I'm still learning so please forgive my stupidity.
I need to sort out my chainrings as I shed a few teeth last year, I was going to take this opportunity to upgrade from a barely acceptable to almost reasonable crankset, however, I'd like a smaller inner ring (oo er missus) but how small do I go?
I currently run a 52/42 double, can I drop straight down to compact (52/32 ?) or should I aim somewhere in the middle?
My concern is really whether or not my front derailleur and chain can cope with the jump up.

 

[monnet]

I don't think it will be possible for you to make that jump, and I wouldn't recommend it either - it will give you too big a change when you want to change gear. A sensible choice would be to move to a 39 inner ring.

Even better could be a proper compact - say 50/36 or 50/34. Another option would be a triple (52/39/30 or 50/39/30), though going for a triple might be more complicated as you'd probably need to change the rear mech as well.

Whatever you choose to do you'll obviously need to adjust the derailleur and it would be advisable to change the chain as well.

 

[RecordAceFromNew]

Frankly it is impossible for anybody to give you sensible and reliable advice based on just the information you provided above. For example, I have a 52/42 chainset and 13-28 cassette on one of my bikes and I would not be able to go any lower by more than 1 tooth without changing my rear mech - it all depends on what components you have at present and their limits.

If you can provide the make, model and configuration of your shifters, front mech, chainset, cassette/freewheel and rear mech, then it should be possible for options to be worked out.

 

[Kirstie]

Sheldon Brown's website has all of the permutations of what is possible with a particular crankset. Don't even ask me to explain it though as it's beyond me. You need to look through his glossary for 'chainrings' and he explains the formulae you need to use to see which chainring size is possible on the cranks that you have.