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Riding Tips & Techniques How to do wheelies? How to back it in? Share your technique with others here. Please!

 
 
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Old 02-07-08, 02:18
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The Art of Braking - Braking Distances Explained

Braking

According to the Hurt Study, in the single vehicle accidents, motorcycle rider errors were present as the accident precipitating factor in about two-thirds of the cases, with the typical error being a slide out and fall due to over braking or running wide on a curve due to excess speed or under-cornering.
Braking is probably the most important action that a rider can perform. Braking allows us to quickly slow down and come to a stop before hitting an obstacle.
Most riders do not fully understand the distance that is required to bring the bike to a full stop. Braking distance increases with speed, and unfortunately the increase is not linear.
If a bike that is doing 30 MPH can stop in 33 feet doesn't means that if the same bike is doing 60 MPH would be able to stop in 66 feet, it actually will take 134 feet! The increase in braking distance is the square of the speed increase.*
Any reduction in the speed you are traveling will decrease enormously your braking distance. Motovike.com provides us with the following chart. Refer to it for a clear idea of braking distances, but be aware that this chart doesn't include your perception/reaction time (which will increase your braking distance considerably).
Speed
Braking Distance
90 MPH -300 feet
80 MPH -238 feet
70 MPH -182 feet
60 MPH -134 feet
50 MPH -93 feet
40 MPH -59 feet
30 MPH -33 feet
20 MPH -15 feet
10 MPH -4 feet

Proper usage of the front and back brakes can be the difference between life and death in a close situation. In a normal situation, braking is pretty straightforward. Unless you are on a slippery surface, use both brakes to stop or slow your motorcycle.
Be aware that the front brake provides 70 to 100 percent of the stopping power of a motorcycle. With that in mind, you want to practice using more front break than rear. An ideal situation is to have a balance between the front and rear brakes, with about 70% of the emphasis on the front.
Let's go over an ideal breaking situation:
  1. You apply both brakes (the front and the back) gradually and with almost equal force for the first phase of your braking.
  2. The weight will transfer forwards as the front suspension compresses, and your arms bend, the front tire now bites into the pavement.
  3. There's now more weight on the front
  4. You now let off most - or all - of the rear brake and increase pressure on the front, which now has most or all of the grip. This middle phase of braking can be 100%:0% - if it is less than 85% Front, you probably aren't braking near your bike's limits.
  5. The bike slows and the forces you are exerting through the brakes and tires diminish (the energy in the bike is proportional to the square of your speed).
  6. The front begins to rise back up on its suspension.
  7. You taper off on the front brake - to prevent a slow speed lock up - and increase the rear brake pressure once more. (braking technique courtesy of Hoddy Hodson http://www.msgroup.org/TIP030.html)
A number of things happen when you start to apply the front brake. First, the shocks will compress as the bike transfers weight to the front. This puts weight and extra traction on the front wheel. At this point, you are doing normal braking. If you continue to squeeze the brake lever, the front brake will get more and more weight on it. Eventually, most of the bike's weight will be on the front wheel. At this point, you are fairly close to threshold braking. If you continue to squeeze, the front wheel will start to complain.
If you feel this, you are at maximum braking. What you are experiencing is caused by the tire locking for fractions of a second then rotating again, and the movement is the tire sliding just a fraction of an inch or so, then regaining its grip, then sliding again. If it didn't regain its grip, it'd go into full lock and bad things would happen.
Just as when driving a car, braking on a slippery surface should be done with a lot more care. Start braking in time because it will take the same amount of weight a lot more time to stop on a surface with less friction than it would on a dry surface with high friction

Last edited by CaptMoto; 02-07-08 at 02:26.
 

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