If you are under 21 years you must sit a test on a 125cc motorcycle which will restrict you to 33BHP for 2 years.

After this time you'll have a restriction free licence which means you are free to ride any size of bike.

If you should happen to turn 21 years before your 2years are up then you can sit a second test on a larger bike. When you pass you may the ride any size of bike.