Contact Us
25-04-2011, 04:24pm
That is an excellent thread and it is a shame that not many riders look into that corner.
Regarding hanging off and steering left to turn right.
Bear gave an accurate explanation of the "mechanism" of the dynamics that will lean your bike to the right if you steer to the left resulting in taking a right turn. A lot of riders do not understand this but act instinctively and that is the whole point. Who cares how it works as long as it does and without fail
However the whole "hanging off" technique absolutely makes no difference to your cornering speed other than maybe a psychological one. And here is the reason purely from the view point of science of motion dynamics:
Newton figured out that everything wants to move in a straight lines, bikes including. So as we start traveling on an arc (cornering in that case) we require sometning to overcome that tendency for traveling straight. All we have is the friction between the tires and the road - the precious traction. There is only so much of it and it does not depend on how big patch of rubber is on the road but only on how much force (the weight of the bike and rider) pushing it into the road. Now there is a good thing. To conteract the centripetal force while cornering, we are leaning the bike into the corner untill it's weight balances it. So now we have more force pushing the tires into a road (the suspension is more compressed than normal) and we have more traction - good thing. Now is the bad news. It does not matter at all whether at this point you are "hanging off" the bike or not as the amount of the centripetal force depends only on the total mass in motion through the arc and it's velocity. The position of the centre of gravity in this case will have absolutely no effect on it. It will only affect the amount of lean required to balance the bike. Correct "hanging off" technique will lower the centre of gravity requiring less lean angle for a given speed but that is all. It might be very important if you have clearance problems but it will not give you any more traction. And the traction is the only limiting factor on how fast you can travel through the corner. So whether you are "hanging off" or seating straight on you can really get through it with the same speed (all other things being equal of course). So why most of the riders do it then? Well, there is a number of good reasons why it is well worth learning and using this technique. First it is a psychological one as it gives you more confidence. I call it the closest thing to a low level flying you can get to without buying an aeroplane. It also helps you to judge correctly your lean angle as someone already mentioned in that thread. Knee in the set position on the ground (requires a lot of balls and experimenting untill you find what that position is) is the limit on how far you can lean the bike before you off the edge of the tire. It helps to have a buddy riding behaind with a camera for a good refererence. Finally, the benefit of lower centre of gravity is increased stability of the whole bike while cornering and a bit of advantage when coming out of the corner - quicker to get it up.
The art of going quick through corners is a combination of the correct line and using maximum amount of available traction to conteract the centripetal force. That means a steady and fluid motion as very little will be left for acceleration (should not even think of it really) or braking which many have learned the hard way - highside for the first, lowside for the second. Both bloody painful and expensive.
Now I am going to practice what I have preached
Regarding hanging off and steering left to turn right.
Bear gave an accurate explanation of the "mechanism" of the dynamics that will lean your bike to the right if you steer to the left resulting in taking a right turn. A lot of riders do not understand this but act instinctively and that is the whole point. Who cares how it works as long as it does and without fail
However the whole "hanging off" technique absolutely makes no difference to your cornering speed other than maybe a psychological one. And here is the reason purely from the view point of science of motion dynamics:
Newton figured out that everything wants to move in a straight lines, bikes including. So as we start traveling on an arc (cornering in that case) we require sometning to overcome that tendency for traveling straight. All we have is the friction between the tires and the road - the precious traction. There is only so much of it and it does not depend on how big patch of rubber is on the road but only on how much force (the weight of the bike and rider) pushing it into the road. Now there is a good thing. To conteract the centripetal force while cornering, we are leaning the bike into the corner untill it's weight balances it. So now we have more force pushing the tires into a road (the suspension is more compressed than normal) and we have more traction - good thing. Now is the bad news. It does not matter at all whether at this point you are "hanging off" the bike or not as the amount of the centripetal force depends only on the total mass in motion through the arc and it's velocity. The position of the centre of gravity in this case will have absolutely no effect on it. It will only affect the amount of lean required to balance the bike. Correct "hanging off" technique will lower the centre of gravity requiring less lean angle for a given speed but that is all. It might be very important if you have clearance problems but it will not give you any more traction. And the traction is the only limiting factor on how fast you can travel through the corner. So whether you are "hanging off" or seating straight on you can really get through it with the same speed (all other things being equal of course). So why most of the riders do it then? Well, there is a number of good reasons why it is well worth learning and using this technique. First it is a psychological one as it gives you more confidence. I call it the closest thing to a low level flying you can get to without buying an aeroplane. It also helps you to judge correctly your lean angle as someone already mentioned in that thread. Knee in the set position on the ground (requires a lot of balls and experimenting untill you find what that position is) is the limit on how far you can lean the bike before you off the edge of the tire. It helps to have a buddy riding behaind with a camera for a good refererence. Finally, the benefit of lower centre of gravity is increased stability of the whole bike while cornering and a bit of advantage when coming out of the corner - quicker to get it up.
The art of going quick through corners is a combination of the correct line and using maximum amount of available traction to conteract the centripetal force. That means a steady and fluid motion as very little will be left for acceleration (should not even think of it really) or braking which many have learned the hard way - highside for the first, lowside for the second. Both bloody painful and expensive.
Now I am going to practice what I have preached
"It is not a shame to not know, the shame is to not know and not to ask"