This is my second post here so far. I've been commuting to work by bike for 32 days now and I can't seem to understand shifting. My husband tried explaining it all to me, but he gets realllly technical and I get completely lost.

Here's my issue: I have a 21-speed bike. On the left side of my handlebars I have a shifter with lots of intervals that don't seem to do anything and take a bit of effort to push up on. On the right side there's about 7 intervals. How do I know when to use the left side and when to use the right?

I've read a few articles online but they're quite technical as well. However, I did learn why my knees ache so much! I have to let myself take it easier I suppose.

I don't commute via road, but on a rocky trail that has a bit of an incline on the way home (which is lovely for me after working 9-10 hrs!). Thanks for any help!

jenn

ps. Anyone know why my left hand always falls asleep while cycling?