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Braking Method
Determined By Speed

By: James R. Davis



We have all heard that 'up to 70% of your stopping power comes from the front brake.' Not desiring to start another war, but it is my opinion that this is historic information - up to 100% of your stopping power comes from your front brake now!


With today's modern brakes and tire compounds it is entirely possible, with speed and good road surfaces, to get so much stopping power with the front brake that you can break your rear wheel entirely off the ground (known as a 'stoppie'), at least with most sportbikes. [This is not good. ] But raising the rear wheel off the ground at high speeds is not the typical problem with over-applying your front brake - it is locking the front wheel and dumping the bike at slow speeds. [You can either do a stoppie or your front wheel will skid, not both and not by choice. It's primarily a matter of how high the Center of Gravity is as compared to the length of the wheelbase.]

So? Well, traditional training argues that for most effective braking you should try to obtain about 75% of your stopping from the front and 25% from the rear if the road is dry, and 50% from the front and 50% from the rear if the road is wet. This might no longer be the best advice because speed is not being considered.

That is, in my opinion, the advice should better focus on what you should do at various speeds. For example, if you are moving at less than about 20 MPH, regardless of the condition of the road surface, virtually all of your stopping can be derived from the rear brake, and if the road surface demands it (slippery, grass, loose gravel, etc.) exclusively. [I advocate using BOTH brakes virtually every time - I am here only arguing that you can rely on the rear brake for most of your stopping at slow speeds - not that you should only use your rear brake.] The slower you go, the more likely your front brakes will grab - thus, you should not be trying to get 75%, or more, of your stopping power from the front brake at slow speeds. (We have already talked about how fast a bike goes down if the front brake locks.)

When moving faster than 20 MPH then traditional advice (75%/25% or 50%/50%) applies depending on road surface condition, paying particular attention to NEVER applying brakes so quickly that you lock either of them, and that during hard braking you should tend to ease up on the rear brake as weight shifts towards the front wheel.

The next Tip argues this far more clearly, and suggests 75%/25% should now be more like 85%/15%. More importantly, it describes 'Taper Braking' as a method to be used at all times. I fully endorse that thinking.

Copyright © 1992 - 2017 by The Master Strategy Group, all rights reserved.
http://www.msgroup.org

(James R. Davis is a recognized expert witness in the fields of Motorcycle Safety/Dynamics.)

     
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