Originally Posted by klebs01
I also don't understand the insistence on the super small bikes to start on.
If a student whacks the throttle then freezes up, there's a difference in behavior for a 250 vs a 500 at the 200 foot mark- the 250 is out of steam, the student has a chance to recover. The 500 is still pulling.
Way back when, MSF got insurance companies to agree that 250cc* motorcycles on a 140x240 foot unobstructed parking lot was a reasonably safe bet. They were right- for 20-odd years, there were no fatalities. As far as I know, all of the fatalities have been on the Blast.
*I think it was actually 350cc, but most of that class faded out fairly soon in favor of similar 250cc or 400cc machines...
As with anything motorcycles, Limiting bikes by engine displacement is silly; HP or max torque might be a better measure, but harder to determine.