Changing from a double to a compact?

martylaa

Hi as above, i'm looking to change my Shimano 105 double chainring to a 105 compact, question is, is it easy to do?
Do i just change the rings or do i have to mess around with the BB?
Do i need to change anything else?
Would i need to have my gears re-adjusted?

I don't mind messing around with bikes as i used to build and restore old bmx's, but i have never learnt the art of adjusting gears and i's hate to mess them up, guess i'm asking whether i could do it or should i just give it to my LBS to change?

sungod

the compact chain rings won't fit in the larger spider of a standard double, so you need to replace the complete crankset (bb stays where it is)

aside from that, you need to shorten the chain a smidge, and lower and adjust the front mech

it's pretty straightforward, you need a few tools but nothing expensive

if you look here...

http://techdocs.shimano.com/

...you'll find all the instructions for installing and setting up shimano bits

the park tool's website is also a good source of generic how-to info with plenty of pictures

martylaa

Spot on cheers for that, already have the Parks tool kit so should be ok, just know I'll mess the feats up though lol