Had to reread the thread, as it didn't seem possible. A 7spd will have long chain life, as the plates are thick(er) (everything being relative). Cleaning every 650miles or so would destroy my 9spd chain; I think I'm getting like 2k on a chain in my travels. Oil every 100-200miles, and off for cleaning in mineral spirits like every 500-600. Interesting, though, that an ultrasonic cleaner might make chain life longer, by getting grit out. I'll have to look at that some day.

[I kinda don't care, hence the rough approximates, as long as I get more than 1k out of a chain. If I did care about chain life I'd probably go back to 7spd.]