Originally Posted by Michel Gagnon
On the other hand, if you really want to practice good spinning, try to climb a 10% grade with a stokerless tandem.
Or try any double digit grade on a road bike when the pavement's wet. Especially if the steep part happens to be at a turn. Stand and mash, and you'll just get wheelspin. Be less than smooth when seated, and you'll still get some wheelspin.
I haven't tried myself (for lack of a MTB), but I hear climbing steep grades offroad requires similar smoothness.