75 below - I do the limit and never been to a track.
75-100 - I'm not afraid to push my car.
100-125 - MOVE BITCH GET OUT THE WAY...
125-150 - This is as fast as my car will go
150-175 - I'd like to see the cops catch me!
175+ - Explanation needed...
On straights you dont really have much to worry about if you thoroughly check your bike. It's a controlled environment and if something happens hopefully I would be there to help ya, or someone else who knows how to deal with the situation, not some passer-by who would most likely further injure you.