They are mounted with double stick tape which is NEAR IMPOSSIBLE to get off, pretty sturdy. Have one mounted on the rear swingarm and it does not come off.
A 1:41 is a decent fast time the fastest lap time this last week was 1:35. I was only running a 1:39-40 but it was a practice day

! I would definitely say give racing a go. It is a lot different when your out there Competing, but it does take riding on a track to a whole new level.
When your racing its about keeping a consistent time, not just having a fast time.