Dear friend,
I always ride my bike to school.It's good to my body and it's really funny.I don't think that riding bike will be bad to you.However,your parents maybe have their own idea.They may think if you ride to school,you will meet something bad,such as car incidents.And you may be robbed.They care about your safety,so they don't want you ride to school.If you really want to go to school by bike,you can talk with your parents about it.You can tell them that you promise you can care yourself.If they still don't allow you to do that,you just obey them.That's all what I want to say.I wish they can allow you ride to school.
Yours sincerely
XXX