These puppies are not toys.
A sportbike can generate enough stopping power on its front wheel to raise the rear in the air. Who hasn’t seen a stoppie? This effectively puts 100% of the stopping power on the front brakes. Most of the real stopping power comes from the front brakes. There are complex laws of physics involved here but we can break it down into something fairly simple.
Some observations to start with and if you don’t believe us try these experiments yourself:
• Using the front brake causes the front forks to compress. Push your bike down the road and press the front brakes lightly.
• Drag a light plank down the road with a piece of rope. Really easy but try it again with a sack of cement on top and you will soon be out of breath. Weight makes a difference.
Logically then if you use your front brakes the front forks are compressed downwards effectively transferring weight onto the front wheel. This increases friction or grip and the harder you brake the better the weight and therefore grip. If you continue to apply pressure all the weight of the bike will eventually transfer over the front wheel and the rear will lift off the ground. As the rear becomes lighter so the grip lessens and the rear will start to slide and then lift off the ground completely effectively negating any braking ability.
Obviously if you apply both brakes evenly the rear will cause drag preventing the weight to be transferred to downward pressure in front and therefore reducing maximum grip. More like dragging that plank down the road with a half empty bag of cement on it. Easier to drag but in motorcycle braking terms a longer stopping distance.
Apply just the rear brake and you lose the friction and stopping power of the front, halving the stopping power again. If you want to slide your rear tire to impress your mates then this is the technique to use as long as you don’t actually need to stop in a hurry.
Sportbike riders have an advantage over cruisers and chopper riders in that the weight of the bike and rider is already angled over the front wheel.
These theories only apply to straight line braking, on a bend applying only your front brake would causes the weight to transfer in the direction of your momentum which is a vector of the direction the front of the bike is pointing and the lean angle of your bike. This would effectively stand the bike upright and eventually fling the bike over the other side. In this case a little rear braking allows you to keep the weight back which in turn will allow you to keep the bike in the correct lean angle for the bend while slowing you down. Go out and try this out carefully and you may be pleasantly surprised with the extra control you have in corners. Over brakingA and standing the bike up in the bends is a cause of a large percentage of bike accidents, usually due to panic by the rider even though the bikes can handle the bends as proved by the racing fraternity. These are accidents that could have been avoided with a little practice. You may even increase your overall cornering speeds with more braking.
Smoothness is the name of the game here. Squeeze the brakes smoothly and you won’t upset the bike. You will also get the best feedback as to when the bike is about to slide or stand up.
Remember a stoppie is performed by squeezing the brake progressively harder but it also requires a concerted effort on the part of the rider to shift body weight and sometimes bouncing the rear shocks to lift the rear high enough to impress anyone. It is very difficult to perform an unintentional stoppie. If you have the urge to impress your mates then go out and practice stoppies. Who has ever been fined by the cops for trying to stop too quickly?
Keeping two fingers on the front brake while riding reduces reaction time and with sportbike brakes it only requires one finger to bring it to a stop. It may feel uncomfortable at first but it eventually gives more confident with reaction times. The other two fingers and thumb can still be wrapped around the throttle allowing throttle control at all times even when braking.
Tags: The Blog
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