Panic stops--how close to 'the edge' am I?

[Phriday]

I've been thinking about this question a lot for the last couple of years.

My only motorcycle "accident (knock, knock)" has occurred while I was practicing panic stops on my old bike.  I was accelerating in a large parking lot to about 60 mph, and picking a spot at which to apply the brakes and seeing how quickly (in feet) I could stop.

There were several drills of me clamping down on the front brake harder and harder.  On the last one, I'm not exactly sure what happened.  I accelerated, grabbed the brake, and suddenly I was sliding along the pavement.  I was wearing a jacket, gl,oves, helmet and boots, so thankfully the only injury I sustained was a strawberry on my left knee.  That TOTALLY solidified my dedication to wearing safety gear, but that's another thread.

Based on what I've been able to determine since, this is what happened:
The front wheel locked, and the bike turned over on its right side.  The rear wheel may or may not have come up in a stoppie.  I can't determine that.  The bike slid along the pavement for about 60 feet.  I went over the handlebars, Superman style, and struck the pavement simultaneously on palms, elbows, knees and (dare I say it) toes.  I slid about 20 feet.  The slide distances were determined by marks on the pavement.  There was a black mark (the tire, I think) about 5 feet long, a space of about 4 feet, then a thin mark about 60 feet long that led to the fairing on the motorcycle (duh).  10 feet after the start of the motorcycle slide, there was a brown mark about 20 feet long that led to my boot.

Here's the part that I have a question about:
How much is too much?  Without ABS, how do you know the maximum braking on your motorcycle?  Is there a way, other than highsiding your bike, that is a demonstration of how hard you can brake?  I feel like it's important to know how quickly I can stop--if I can't stop in time, maybe I can swerve, or turn outright, or make some other evasive maneuver.

Does anyone have any guidance on this?

Phriday

[red baron]

Bike slid 60 feet?


How fast were you going?

[woodyracing]

Do some trackdays, you can learn a lot more about braking than you can learn practicing in a parking lot IMO.

Plus you haven't lived until you've had bits of rubber from the front tire fly up and stick to your visor while braking.

[Michael]

Here's the part that I have a question about:
How much is too much?  Without ABS, how do you know the maximum braking on your motorcycle?  Is there a way, other than highsiding your bike, that is a demonstration of how hard you can brake?  I feel like it's important to know how quickly I can stop--if I can't stop in time, maybe I can swerve, or turn outright, or make some other evasive maneuver.

Does anyone have any guidance on this?

Phriday

Here is a website that you might enjoy reading -- http://www.msgroup.org/articles.aspx

There is an article there called "Stopping Distance And Time: The Math Is Simple" at http://www.msgroup.org/Tip.aspx?Num=032&Set=

[fasterblkduc]

Do some trackdays, you can learn a lot more about braking than you can learn practicing in a parking lot IMO.

Plus you haven't lived until you've had bits of rubber from the front tire fly up and stick to your visor while braking.

+1  Practice in a controlled environment like the racetrack is much more beneficial. You're wondering about braking while swerving a little, (from the way I understand your question). A lot of seat time at trackdays can help you understand this more because as you get more comfortable using the brakes at high speeds going into corners, you will start to use the brakes more aggressively and will eventually start trail braking into the corner closer to the apex. As a racer, I use this technique all the time. It takes time to develop this skill but after you do, you can comfortably brake hard and continue to brake hard while intitiating a turn.
When you see racers outbrake each other, we are grabbing the brake very late, and then holding it all the way to the apex of the turn where our lean angle is the farthest. Then we are back on throttle and driving out.(over simplified version)
It's not just a matter of grabbing hard and hoping that you stop fast. I instruct both street riders, and racers at a performance riding school. One of the things that we teach is, "slow hands make fast riders". It applies to your situation here because you want to use your brakes, and steering inputs, in a smooth controlled manor. From the sounds of your crash, you likely were grabbing the front too hard for the conditions. I just skimmed the article posted above but I did catch one thing that backs up what I'm saying. There is a reference to how racers can stop faster and the reason is that we know how to ease on that brake lever in the most efficient way possible to maximize our braking without locking up. We routinely do unintentional stoppies into corners and are pushing the limits of that front tire right to the edge.
The only way to learn this is on a closed course with a large variety of turns. I highly recommend a performance riding school to help you with this. I don't recommend an MSF course for this. That is a fine course but does not teach you performance riding techniques.
Hope this helps!
 

[Phriday]

I was accelerating to about 60 or 70 mph, so somewhere between that and zero.  I think it was closer to the 70, though.

Yeah, slid right by me on my left, slowly rotating as it slid. 

I think if I'd SEEN it and not DONE it, it would have looked pretty cool.

Phil

[Dietrich]

10 feet after the start of the motorcycle slide, there was a brown mark about 20 feet long that led to my boot.

I would think the brown mark would have led to the seat of your pants? 

I gotta hand it to you for your dedication in practicing.  I wish I could find a lot in my area to try some of the drills in the books I have.  It goes without saying that your shortest stopping distances are going to be determined by road conditions in a big and unpredictable way.  I'm not sure how to get a feel for the "point of no return", but know that the times I've locked front on the street were due to road conditions and overly agressive "panic" braking (aka - stabbing the front brake instead of slowly squeezing the lever).

Track days, as recommended, are a ton of fun, and a great way to learn.  I've only done two, but it's so nice knowing you're in a controlled environment, with no speed limits, etc.  And plenty of friendly people around to answer questions and give pointers. 

[Statler]

upright you can lock the front for very short periods and release with no real problems while practicing in controlled environment at slowish speed.   I hear it before I feel it in those situations.   Let go quick.   


Alternatively, if worried, Kieth Code has a brake bike with outriggers you can truly lock as long as you like without going down, but I consistently stoppied it instead of locking because I couldn't get my brain to grab brake instead of feeding it in.

[DoubleEagle]

If you can't do track days , try riding the same roads over and over again. Find the corners that are the tightest and practice entering them at faster and faster speeds until you find that speed that is too hot or you feel uncomfortable going that fast into that corner and then practice learning to turn your bike better.

What I have found is a corner that I can't brake hard enough to take it without running through it is one that I can take by getting better at setting up for that turn , leaning to my maximum , counter steering , moving my inside shoulder and Butt cheek inside of the bike and pushing against the outside of the gas tank with my outside thigh.

I hope you can get a picture of that in your head. As you move your inside Butt cheek to the inside of your bike , move your inside Shoulder down inside but square to your line .

I have gone into corners on the back roads too fast to brake enough to make them sitting relatively straight up so I must and have learned to a degree to make those corners by setting up  ( getting myself in the position on the bike like I have just described ) and then braked up to the entrance to the corner , looked through the corner to where I want my bike to go , and then commit to the body lean and position on the bike to make the turn.

It's scary but unless there is gravel or sand or other substance in the corner I'll make it and that gives me confidence to take on the next one I encounter.

It will take much dedication and practice but anything that is worth anything generally does.

Dolph     

[Jetbrett]

I've only had to panic brake once so far.  I had a pick-up cut into my lane only a couple feet ahead of me only to immediately come to an abrupt halt to pull into the median on an interstate.  I could feel the front and back locking up...kind of a shudder...which gave me enough warning to slightly back off and keep it upright.  I didn't hear anything from my tires, but when I am really focused..and this got my attention in a big way...I tend to ignore sounds to the point that I don't hear anything at all.   

[Moronic]

On the last one, I'm not exactly sure what happened.  I accelerated, grabbed the brake, and suddenly I was sliding along the pavement. 

The grab is likely the issue here. The front tyre needs a little time to compress and spread as the brake comes on. A squeeze will do the trick. Hard to describe the difference but if you've been riding two years now you'll likely get it.

See post above re stoppies on the Keith Code bike.

Here's the part that I have a question about:
How much is too much?  Without ABS, how do you know the maximum braking on your motorcycle?  Is there a way, other than highsiding your bike, that is a demonstration of how hard you can brake? 

Phriday

No there's not - that's why ABS is so handy. After all, the maximum braking will depend on how much grip is available on the particular bit of tarmac under your tyre at the time. Only way you can learn that is by locking the wheel. And once the wheel locks, you have to release the brake to recover, which kind of misses the point of the exercise. ABS works by doing this very, very fast; humans can't emulate.

In the absence of ABS, a controlled squeeze on the brake gives you a chance to pick up subtle signs that you're near the limit. But perhaps the point is that you're not really looking for the maximum possible braking. You're looking for the maximum reliable braking. Which is usually plenty, if you can train yourself to squeeze rather than grabbing, even in an emergency.

[scott_araujo]

If you can repeat the drill many times feeding in more brake each time check the pavement under your front tire after each stop.  I forget whether it's Code, Pridmore, Hough, or someone else who said it but when you get it just right there will be a nice gray streak on the pavement.  It's the tire shedding just a little rubber.  If you go any further then you lose traction and it skids. 

When you're right at the edge it is supposed to have a very distinctive feel that you can recognize once you know it.  I can't say what that feels like as I never tried to get that close to the edge on purpose.  I have had the front end start to growl and rumble on some hard stops, maybe that's it.  I can tell you that if you lock the front wheel and let go right away before the bike gets out of line you can recover without incident.

Scott

[OT]

I don't think it was mentioned....at high speeds you'll want to use your legs against the tank to support as much of your weight as you can.  It's possible that you wound up putting a lot of weight on the bars after you squeezed the lever and twisted the front end, especially as you said the bike fell to the right.

[Ivan]

I can tell when I'm reaching the limit of traction by the sound that the front tire makes.   The fly screen also starts to do a little dance from the vibrations.

[Desmostro]

Suspension set up/tires are another thing that will determine quite a bit about what will happen in a panic stop.
My new 848 had a set up that was way too stiff and when practicing this I could skid the front end. NOT DESIRABLE
I went to the track and got a pro to set me up. Took 10 minutes, cost next to nothing.

Days later I was entering an intersection when a drunk woman in a 3.5 ton SUV ran the red light plowing through the intersection blasting cars out of the way. No where to go, I grabbed a handful of brake and stoppied at about a 50degree angle, 2 feet from the wave of metal & came to a rest untouched.
pheeeeew

Boy I'm glad I got that set up done.