Engine Breaking VS Brakes

[Duc796canada]

Who was it that said they used only their rear brakes when dirt riding? Probably not motocross!! In motocross even at novice speed, all brakes are used, the rear has lots of "other" uses, but the front is used LOTS!!

[duc996]

I use my rear brakes during u turns and slow moving traffics

[pesto]

It's simple mathematics. 

There's more than one force at play here. There is N UP from the force of gravity pushing you down, and there is N opposite to the direction you are travelling from the force of your motorcycle moving. Therefore, the total N is always more than the weight of the bike and rider.  μ is increased by using both brakes, increasing brake-wheel friction which increases tire-road friction which increases  μ.

I think  .

http://hyperphysics.phy-astr.gsu.edu/hbase/crstp.html

This is of course assuming that you are not on an 1199R travelling at near light speed with the headlight on.

[Triple J]

There's more than one force at play here. There is N UP from the force of gravity pushing you down, and there is N opposite to the direction you are travelling from the force of your motorcycle moving. Therefore, the total N is always more than the weight of the bike and rider.  μ is increased by using both brakes, increasing brake-wheel friction which increases tire-road friction which increases  μ.

Friction (u) is a constant value, dependent on materials. It doesn't change due to braking. The normal force (N) is what changes. The total force is defined as N x u.

I agree that N is higher than just the static weight of the rider and bike, due to the momentum of the bike.