Oh, and re: the knees...

Thanks for pointing that out. The whole reason I started biking was to PRESERVE my knee (low impact and all that). I tore out my Right ACL learning to play soccer the other year at age 39. Being in school and only having student insurance, I haven't gotten it fixed yet - just did some rehab.

It's stable enough for everyday use, though I feel it slipping around a bit when I mow grass on the hills. But I stopped jogging 'cause I didn't want to do any more damage to the meniscus before I could get it repaired. So if gearing lower on the bike will help preserve the knee too, then I'm there, babay!