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Discussion Starter · #1 ·
While looking thru info on tyre pressure and braking distance, I came across the biggest variable, as explained by riding instructors.

The stopping distances were quite large. They expressed it in distance to stop, from various speed, and the G forces involved.
Anyone care to suggest what was the factor involved, with the large differences in stopping distance. Actually I have tried that approach before, and it does not seem to work.
Rather I will tell you, and then the newbies can tell me I am wrong.

Newbies / beginners, one half G. Experienced riders .7 G. Expert riders 1 G.

And I would further suggest that road race riders, with an expert license are the best at stopping. For the track day warriors. Has your braking improved since riding at the track? For the folks that have taken advanced courses. Has your braking improved since taking the course?

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Experience? By that I mean assessing the situation, reaction time, amount of brake pressure to apply for that situation without losing control. Or are you talking about some sort of theoretical math?
 

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Discussion Starter · #3 ·
Experience? By that I mean assessing the situation, reaction time, amount of brake pressure to apply for that situation without losing control. Or are you talking about some sort of theoretical math?
Practical application. Person on bike doing 30 and stop. They knew in advance they would be asked to stop, but still there is a reaction time. Usually given as .75 second. I suppose the G force was calculated. The distance was easy to measure. The test was done at a variety of speeds. With riders of different skill levels.

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Got it. The reaction time will become 'second nature' as you gain experience. I simply don't think about such things. Example: A few years ago, a friend of mine bought his first bike. He took a safety course to get his license. After completing the course and getting his license, he started telling me about everything he learned. Counter steering, trail breaking, slipping the clutch, things like that. I had no idea what he was talking about. All of these things I learned by experience and never thought about, much less give a name to.

So with that being said, is it possible new riders are thinking too much about what they learned during the course?
 

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Discussion Starter · #5 ·
So with that being said, is it possible new riders are thinking too much about what they learned during the course?
Quite likely.
But many may have a brain freeze, in a critical situation. Most often something solid appeared in front of them, or they over cooked a corner.

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Anyone care to suggest what was the factor involved, with the large differences in stopping distance.

UK
Tire inflation pressure...pro or novice...over-inflate the tires ~20% = stopping distance increases ~20%..the reverse is also roughly true...~20% under-inflated = ~20% shorter stops.
 

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Discussion Starter · #7 ·
Tire inflation pressure...pro or novice...over-inflate the tires ~20% = stopping distance increases ~20%..the reverse is also roughly true...~20% under-inflated = ~20% shorter stops.
The difference between the pro and novice is 100%. That would seem to exceed tyre pressure variance. Too, we can assume that all the tyres were at the correct pressure. It was a controlled course with pro instructors. And, are you still quoting from the Slovakian article and the old Citroen?

I am not disputing tyre pressure makes a difference. I have BTDT. In the real world it is rider experience that makes the difference.

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I hit the rear as I seldom use it. So I hit to find it then apply it. Now practicing it I have no problem because I've found it and know right where it is. And I'd say most are lying if they don't have similar problems if they are a front brake rider. U-turns no problem as that isn't an emergency anyway. I have no idea what happens with rear brake users. This is one reason I like the newer linked brakes. As they get it working properly on gravel roads you'll see fewer going down.
 

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Notwithstanding learning the braking/riding/etc., terms of all the machinations required for riding a bike from the MSF (or other), it is probably a worthwhile mental-inventory even for experienced riders – a lot of things that I learned by trial and error, can be improved somewhat, once I dissect the steps/process/procedure. When it comes to stopping, I doubt I only use 0.75 sec to see the hazards, have evaluated it and then react to it properly UNLESS, I was looking for it to begin with… once committed, I can (or could…) brake with the best of them, but that comes from knowing the bike and using it frequently as daily commuters almost inevitably do… But somewhere in the first couple of thousand miles on an unfamiliar bike, I think the rider should attempt a maximum, or near-maximum, stop – just to see how it will react… (yes, probably even bikes with ABS, although I’ve never ridden one…)

But -- I’d guess my actual reaction time when deep into road-hypnosis (out of the slab) is closer to two seconds… the only way to combat that is ether to stay race-track-alert (usually attainable for the average rider for no more than 20-30 minutes – even pros fade after a bit…), or to build a cushion that keeps most likely hazards several hundred feet away… (my method).
 

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I have practiced many times hitting the rear brake just hard enough to cause it to lose traction and immediately backing off the right amount to regain traction, then reapply as I'm pulling hard on the front brake, while leaning back to gain a more equal distribution of weight. I have repeatedly done this and have gained confidence in using it in a fast occurring situation.

Gravel roads are something I almost never have to worry about around here, The occasional friends driveway but usually they are very short and never a problem.
 

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TR I think most people would like to say they apply the brakes while in fact they slam or hammer them in an emergency. I know I do, much like you hit them hard and back off and re-apply trying to keep them at the just barely complaining level. In the time it took to type this I have probably applied and re-applied the rear brake 6 or more times. :)
 

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TR I think most people would like to say they apply the brakes while in fact they slam or hammer them in an emergency. I know I do, much like you hit them hard and back off and re-apply trying to keep them at the just barely complaining level. In the time it took to type this I have probably applied and re-applied the rear brake 6 or more times. :)
Yep, good observation, and I completely agree...
 

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Discussion Starter · #14 ·
In an emergency situation do you hit the brakes or apply them?
Disclaimer: What I have to say about braking may differ from the main stream thoughts.

I squeeze the brakes. For most street riding, they are gentle slowing down events. Typically 2 fingers on the front brake, squeeze a little, push the rear brake, add pressure as required. Same operation for emergency stops, but with a lot more force.

With the old drum brakes, it was a full fist ( all fingers ) pulling hard, almost to the point of snapping the cable. And they still took forever to stop. 180 feet from 60 for an 850 Guzzi. With the single discs like my XS400, it is still a full fist with a lot of force. It stops better than the old drums, but is still not that great.

The Suzuki has ABS that I do not like, so it is a fairly hard pull and the ABS triggers. It does stop quickly.
The Triumph has the same brakes, and no ABS. Sweet. It only needs 2 fingers. A full fist could probably lock the front wheel which I like, as I can ease off the lever. Most bikes can lock the back wheel, after the front brake has been applied quite severely.
Even in an emergency type situation, I like to squeeze a little first, which drops the front end, then apply more pressure.
My grip is quite strong, so my squeeze might be a hard pull to some.

At the track we had 220 pound bikes, with 8 leading shoe drum brakes. They could lock the front wheel at 120 mph. The initial squeeze would be a bit more severe, but the basic program was used. The front tyre made a high pitched squeal when locking up, the rear made a duller squeal. The ability to notice the subtle clues, is what separated the good guys, from the not so good.

When the first discs came out, they were not as good as the modern stuff. I had one set of twin discs, that could lock the front wheel at 130 mph, on a 315 pound bike, but it would fade. Later after having O ring problems I chucked it in favor of a large Lockheed unit. The initial grab was not as good, but it was consistent and did not fade. It used to go crimson and blue at the track, and make cool crinkling sounds after use.

Of the newer bikes, the brakes I liked the best were on the SV650 Suzuki. Similar to the bigger bike, no ABS and 370 pounds.
I think my XS1100 Yamaha with 3 discs, has similar brakes to what many here are using. Quite adequate, but not great.

For those that think they are good at braking, the track is a very humbling experience. However, you do not have to do that, just stay safe on the streets. Negotiating heavy traffic, can be a greater skill to have for street riding.

UK
 
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