Emergency Braking

[p.dath]

One thought does come to mind with doing stops from high speed (say 200Km/h+) on a track compared to 100km/h on a road.

I think everyone agrees that the rear break can only have an effect for a short period of time until the weight moves to the front tyre.

If you consider stopping from 200Km/h. Lets pretend that takes 6s. Lets pretend the rear brake had an effect for 0.5s. That would mean the rear brake would only have an effect for 8.3% of the manoeuvre. However I'm guessing that at higher speed their will be far more momentum pushing weight on the front tyre (momentum = mass times velocity). So the 8.3% could be much smaller.

The study found the average braking time from 100Km/h has a tad over 3s. Lets pretend the brake still only had an effect for 0.5s. That now equates to 16% of the time.


I'm wondering if track riders don't bother with the rear brake as much (if at all) because the perception of the amount of time that it makes any difference is so much smaller.

So I'm wonder further if perceived impact of rear braking is greatly affected by the speed you start your braking from.

[mossy1200]

One thought does come to mind with doing stops from high speed (say 200Km/h+) on a track compared to 100km/h on a road.

I think everyone agrees that the rear break can only have an effect for a short period of time until the weight moves to the front tyre.

If you consider stopping from 200Km/h. Lets pretend that takes 6s. Lets pretend the rear brake had an effect for 0.5s. That would mean the rear brake would only have an effect for 8.3% of the manoeuvre. However I'm guessing that at higher speed their will be far more momentum pushing weight on the front tyre (momentum = mass times velocity). So the 8.3% could be much smaller.

The study found the average braking time from 100Km/h has a tad over 3s. Lets pretend the brake still only had an effect for 0.5s. That now equates to 16% of the time.


I'm wondering if track riders don't bother with the rear brake as much (if at all) because the perception of the amount of time that it makes any difference is so much smaller.

So I'm wonder further if perceived impact of rear braking is greatly affected by the speed you start your braking from.

Correct the rear brake has most effect while bike is squatting then as the rear becomes light the rear has less effect(but still some).
The thing is in an emergency stop the idea is to cut speed quick and as the initial braking is at the highest speed the distance travelled is greater.Therefore as far as distance to stop goes the initial braking and reaction time has the most effect on the stopping distance.
Reaction time is a huge factor.Those who ride casual and not scanning ahead for possible danger have very slow reaction to threats.
If you are scanning for danger you are ready to act.

[scracha]

The DSA reference on Google only goes up to page 33.

The whole book is online at the URL I gave so I dunno where you get page 33 from. Oh look, Scotch mist.

The dmvnv talks about using the rear brake.

before the front?

The "How to ride a motorcycle" book also talks about using the rear brake.

before the front?

They just discuss emergency braking in general, and pretty have similar results to the study I posted.

You could be a politician as you keep ignoring the facts that don't agree with your own point of view.