I commute 23 mi. r/t about 200-220 days a years.

I get about 2,000 miles on a Dura Ace 10spd chain......and I get about 6,000 miles on a cassette.....I run a triple and spend most of my time in the big wheel....sharks teeth appear around 12,000 miles. I don't even remember the last time I shifted down to the granny wheel.

I do clean the chain every week and about once a month, take the cassette off and clean that...if I ride in the rain during the week, I do wipe the chain off and relube when I get home.

have tried different lubes, etc. to try to get a longer chain life, but it just hasn't had an effect....tried going to an Ultegra 10spd chain...had no effect....2,000 mi., so I went back to a Dura Ace chain (slightly better shifting, although cost was considerably less)