[adouglas]

Good advice above, especially about having an instructor follow you.

Archy, I was there about two seasons ago. My $0.02 for what it's worth:

1) Getting lapped on a small bike doesn't count. A chimpanzee can twist the throttle and go fast in a straight line, so OF COURSE everyone on a bigger bike is going to pass you, even if they're not as good as you. What matters is how you're doing in the corners relative to others in the group. Are you always catching up in the twisty bits? Are you braking later/carrying more speed into corners than those around you? Are you getting on it earlier at the exits?

2) A concern that hasn't been mentioned is being a good track citizen. I really didn't want to move up if I felt I was going to become a pain in the neck for those in the higher group. That's where independent confirmation (via an instructor/coach following you) comes in. They know what you don't; namely, the actual pace of the higher group.

3) Depending on what you happen to be working on, being the fastest rider in the slower group can be more fun than being the slowest rider in the faster group. Passing (safely) is a hoot and an important skill even if you're not a racer. If you're faster than the other riders in your group, it's a target-rich environment. If you're unable to make those passes in the corners where horsepower doesn't matter as much... well, then you're not really the faster rider, are you?

4) My own personal gauge regarding comfort with moving up wasn't lap times. It was whether I felt that I was ready. If I'm riding near the limit of my ability (getting out of the comfort zone and making mistakes) and still having other riders doing better/going faster than me, then it stands to reason that I don't belong in a faster group.