AITA for wanting to ride my bike on the road?

I (16M), live with my grandparents (60+). They were always very protective about my safety whatever I go, for example I could only go to the supermarket at the end of the road walking when I was 13. I got a bike when I was around 10 with the requirement that I could only ride on my backyard (which is not very big), which at the time made me not really want to ride it that much and consequently I didn't know how to ride a bike, and they always pushed that fact on me.

Recently I've been wanting to ride it more since all my friends also use them to go everywhere and I'm always the one going on foot. So I've been learning to ride it from the past 3-4 months every weekend and I'm confident that I am able to ride it outside. The problem is that my grandparents still don't let me ride it outside and locked it in the garage since they discovered I want to use it. Their reason is that the road is very dangerous and it is not how it used to be back then, and even if I be cautious some guy could mess up and run over me. I slightly agree with them, but I've made it clear what I would only ride it on roads or places that doesn't have much traffic, like a park, but they still don't allow me, and say I'll just be allowed when I turn 18. I've been insisting on this for the last month, and because of that they have been calling me rebel every time they can which pisses me off. (My father also has an obsession with motorcycles and they've been trying to convince me to not own one or like motorcycles since ever).

AITA for disagreeing with them?