I don’t think it’s that the radius of the wheels makes it possible (or not) to fit brakes. You can make very strong brakes with relatively small discs for example. You can see on a sportscar that the discs are nowhere near the radius of the wheers (like they are probably 1/2 the radius).
All the forces for acceleration, braking and cornering for a vehicle are limited by the contact surface of the tyres on the road. This is drummed into you quite viscerally when you ride a motorcycle and have 100+ bhp engine and you find yourself leaned over having gone into a corner too fast. If you try to brake now that you are leaned over, your bike will skid out because you only have a contact patch about the size of the palm of your hand and your braking will use up some of the friction that would otherwise get you round the corner.[1]
Bigger tyres mean more contact with the road so you have more friction available for braking (or acceleration).
[1] on a bike your best option in this scenario is to keep your head up, look where you want to go, keep your speed constant and trust that your tyres will hold you and you’ll have a little bit of luck and not meet a patch of spilled diesel, sand, paint etc and slip out.
All the forces for acceleration, braking and cornering for a vehicle are limited by the contact surface of the tyres on the road. This is drummed into you quite viscerally when you ride a motorcycle and have 100+ bhp engine and you find yourself leaned over having gone into a corner too fast. If you try to brake now that you are leaned over, your bike will skid out because you only have a contact patch about the size of the palm of your hand and your braking will use up some of the friction that would otherwise get you round the corner.[1]
Bigger tyres mean more contact with the road so you have more friction available for braking (or acceleration).
[1] on a bike your best option in this scenario is to keep your head up, look where you want to go, keep your speed constant and trust that your tyres will hold you and you’ll have a little bit of luck and not meet a patch of spilled diesel, sand, paint etc and slip out.