SRAM Compatibilty

aidso

Sorry I know this has probably been done before - but I'm having a complete 'mare.

I've a SRAM X7 front derailleur with SRAM double rings, KMC chain and SRAM 10 spd Cassette.
Can I use RaceFace chain rings on the SRAM x7 derailleur? As finding exact SRAM ones are very expensive
Something like this with the X7?
http://www.chainreactioncycles.com/race ... prod130749

sniper68

Yes.
As long as the BCD(Bolt Centre Diameter) is the same you can use any chainrings.

larkim

Or you can use even less costly NW rings instead of paying the premium (albeit not huge) for raceface rings.

But if you're not planning on using a single ring (you don't say in the original post) you wouldn't want to put a NW ring on in place of a non-NW ring in a double as it would be very challenging to get it to shift off a ring which is specifically designed to keep the chain in place.

Just measure the BCD to be sure on your current crankset.

aidso

Ok cool sounds like a winner.
I replaced the outer ring and am starting go think it's not compatible with the existing smaller ring. It looks too straight and when I change above 7th gear, the derailleur drops the chain.
Inner was a SRAM and outer was a Truvativ. So gonna replace both with something like the Race Face linked above.

Can the cassette be either SRAM or Shimano or does it have to match the rings?

larkim

[Edit - mea culpa for not spotting that you weren't after narrow wide / NW rings at all!]

Truativ is a SRAM brand (since 2004). I'm not sure there should be any compatibility issue with two different branded rings (so long as they are appropriate to the rest of the chainset), but perhaps there is an issue with the ring you bought and the chainring bolts not being the right length? Or perhaps the derailleur mech needs adjusting after the new rings were installed?

aidso

"(so long as they are appropriate to the rest of the chainset)"

What does this mean? Says above only the BCD diameter matters..is that not correct?

cooldad

Pretty much, he's waffling.

larkim

I was thinking 10spd, 7spd etc etc, but of course that is irrelant and I was spouting waffle. Sorry!