To the "replace both sprockets" crowd I say this, I replace my chain every year or so anyway because I want it to look good.
I'm not trying to set any chain mileage records. I normally change the front every two rears and it has worked fine for me so far. I've NEVER broken a chain nor have I EVER seen a chain break in 30 years of riding. The only chain related problems I've seen were due to improper clip on link installation, which is why I always use the rivet style link. Even with that being said, the clip link failures were ALWAYS due to vise grip installs/mis-aligned chains. If they had used a chain press and aligned the chain, I doubt that there would have been problems.
