Quote Originally Posted by jonnydangerous
dont want to add insult to injury but is it really advisable to put a 415 pitch on a full power RS for a bike on the road/your everyday transport?.......
id have thought that the 520 would have lasted MUCH longer, and been the sensible bet even if it loses the odd horse power in frictional losses.......

415 might not last very long mate, even IF you find one in x ring or o ring................
Got an O-ring and from everything I've read it seems they last about the same distance as the engine, about 10k miles, I've had the 520 that I've just take off since I got the bike just over a year ago and I've had to adjust it once! Needed to replace it because I managed to mangle it a bit by resting the engine on it :/ it was ok just a bit rough but now I have money again I wanna get it running properly.
The only reason they put a 520 on as standard was because 415 chains aren't what you'd call easy to come by, from what I've read moving down to a 415 makes the bike much more responsive and lively. You have to take into account that unless (*cough* until*cough*) I get the cylinder tuned and get the head machined the bike is only putting out about 23-24 bhp so the strain on the chain isn't what you'd call huge!
Ill give it a go and if it all goes horribly wrong and the chain wears out in no time at all ill swap it back over to a 520.