Originally Posted by
tetonrider
thanks! will the Shimano 9-speed MTB RD work with a 10-speed cassette, then? very interesting.
Yeah, it's a fairly common setup on tandems in fact.
Going back to the original post, 75rpm isn't necessarily that bad on a steep climb. But if you're going to be at high altitude, it's a good idea to have a couple lower gears than you normally use. I see from the course info that it tops 10000ft above sea level more than once.