Got a standard SRAM red 39/53 but have an upcoming race which is supa hilly...can i just change the chainrings to compact sizes then swap out the red cassette to offer more ratio options - will this work?
cheers
Your best bet is to just change the cassette to something like a 12-27 or 11-28 - the smallest ring you can fit to a standard (ie not compact) chainset is normally a 38t.
FFS, its not the darkside, i hate that term....
Is it a race or a sportive, if its a race then 39x25 should be all you should\will need
If its a sportive then compact gearing would be better, you will probably have a minimum size of inner you can put on a normal spider, best checking, you might also need a new chain as it will need to be shorter
You won't be able to just change the rings. The bolt holes will be in different places as compact rings have a smaller diameter. Changing the cassette is ok but remember to check the capacity of your rear mech (generally about 28t for road) and also chain length. Also depending on how old the chain is you could have some chain skip issues when you put on a new cassette. A new chainset might be easiest.
Cheers
Andy
New cassette is easiest and cheapest.
5 minute job to change it, the mech will handle up to a 28T, the chain *should* be fine (but run through the gears in the workstand carefully before taking it out on the road!)
I do the same on my CX bike for the Three Peaks race, swap my usual 12-27 9sp for a 12-34. The mech (XTR medium cage) needs a turn of adjustment on it's b-tension screw so the jockey wheels clear the larger cassette but that's it, the chain is fine, the mech can handle up to 34. Dead easy.
cheers folk... looks like the cassette is the best option, i'm runnin a sram force rear mech so will check if this will take a 28t. anyone want to swap a mint red chainset (170) for same but compact???
oh, apologies to tragically1969, i will never use that term again!