It's regional...I've ridden in Boston on a magnum going above 30, no problems. Now take another example...
There was a thread on a regional message board here in Boston about a girl on a scoot riding through Arlington, MA - it was all stock 50cc, but she was going about 40 I think. Speed limit in town was 35 in a city where they know their bikes. She got pulled over and slapped with the following:
- Exceeding the posted speed limit (No questions there)
- Driving without a license (meaning since it violated the speed restriction, she should have had motorcycle license)
- Driving an inproperly regestered vehicle (meaning it should have been registered as a motorcycle since it was exceeding the maximum speed)
- Driving without insurance (since she didn't register it as a motorcycle and therefor wasn't required to obtain it with the current registration)
She was made to walk her bike home, which was about a mile away. She's fortunate that they didn't impound the scoot! So once again, it boils down to the area in which you ride. Some cops, like the ones in Boston, really have better things to do than to catch people going 5mph over the speed limit; others who are in a smaller town with less things going on have cops that are more than willing to hassle the lower displacement bikes. The way to avoid all the hassle is maintain the speed limit whenever necessary, and be sure to be extra careful in cities that have cops that are a little less busy.