highside prevention?

[cmoore04]

hello everyone. I'm not sure this is the correct place for this post, and I'm sure this has been covered before but I've been searching for a while and can't find an answer to my question. This has been driving me nuts all day and I need closure...
I was waiting on a side street to hwy 17 for some friends in cars to catch up me for a carpool to the beach. I was on less than perfect pavement and on an uphill incline. The passed me and I hit the gas. The rear started to get lose, and as soon as I realized it was-- it grabbed and I highsided. My question is could I have saved this, did I screw somthing up? or was I a unlucky victim of circumstance. It happened so fast I don't think I hit the clutch or either brake, I might have let up on the gas though.
Thanks in advance for the piece of mind,

[Ratters]

Basically don't hit the gas hard enough to get sideways and you'll be fine. Letting off the gas would have helped the rear tire hook up and toss you off, but high sides can happen so fast that there's not much you can do about them. Just be real careful about when and how you spin up that rear tire. Also, don't stomp on the rear brake mid turn as you can do the same thing.

I remember in my younger days locking up the rear brake (I just started riding on my cm400) and the bike was about to lay down on my (i.e. crash) but the rear then hooked up and proped me straight up. In the middle of the intersection. With everyone staring at a stupid kid on a motorcycle with no helmet let alone any other gear. Ahhh, a proud moment. :teeth

[NOTCH1]

should he also have engaged the clutch when backing off the throttle?

[SaloSV]

hmmm, interesting topic.

Let me get this out of the way: Keith Code talks about this in his book at great length. A Twist of the Wrist II.

Here's my take on it:
Yes, you could have prevented it. But not the way you might expect. Anytime a slide begins to occur coming out of a corner, it only means that the amount of throttle applied is too much for the traction of the tire at that lean angle. This we all know and is obvious.

But, when not prepared for the feeling this gives us, a survival reaction is induced... namely chopping the throttle, or reducing it. This creates opportunity for traction, but in the wrong way at and at the wrong time. When thre rear slides out the natural reaction from the bike is to turn the front end away from the direction of the turn (i.e. the rear end coming around). When you chop or reduce significantly (as in an "oh shit" moment), immediately traction is reinserted into the equation, instantly aligning the front and rear end, sending the weight of the bike around the pivot point of the contact patch, usually resulting in a high side (unless you're lucky somehow).

My basic understanding of "seat of the pants physics" says this, trust the bike will do what it is designed to do... that meaning, it will align itself. But you have to continue your roll on in order for that to happen. Obviously, this requires a serious re-education of rider habits, and comes from watching the pros. You'll see them come out of corners really hot, and you'll see the bike give a quick wiggle jerk (sometimes). this is what is happening. the bike is aligning itself in a more controlled manner, with the majority of the forces continuing to move forward.

tends to the old saying, "when in doubt, GAS IT!"

also, think really hard about the flat track racers on the motards. that entire race is a slide! if they chop, its a disaster!

now, this pertains to rear slides only. front end slides are a different story.

but, if you're sliding out on the street coming out of corners, you have issues. especially if you're running with cars.

take it easy bro. we love you, we really do.

[Enchanter]

Originally posted by NOTCH1

should he also have engaged the clutch when backing off the throttle?


Doing that will allow the rear tire to regain traction much more suddenly and abruptly. That could actually cause the highside if the rear tire is 'that' much out of line with the front tire.

[kiltwearinfool]

A slide initiated by a road anomoly (gravel, oil, etc) is different than a slide initiated by a tire condition.

Road Gunk slides can be predicted and prevented by paying more attention to the road surface you are riding on. As you discovered, they have the habit of correcting themselves before you can do much of anything, simply because you are driving through the cause of the slide (sand, snow, water, etc) and the tire's ability to grip the pavement has not changed, but the pavement surface has.

Slides by Tire require greater attention paid to your feel of the tire's contact patch. These slides are caused more by a change in the tire's ability to grip the riding surface (worn tire, too much throttle, cold tire, leaned over too far) than a change to the pavement.

Yes, there are ways to ride around a sliding wheel. Throttle control is one. Changing how your weight is distributed on the bike is another.

[Alexey]

There are 2 things you can do. In order to prevent a slide, be smooth with the throttle. In other words, as you accelerate, do not use it as an on/off switch, rather do a nice smooth roll-on. This does 2 things. Firstly, it reduces the probability of overstepping the edge of traction. And secondly, if you do overstep that edge, you'll do so by a little bit and you'll have a much greater chance of not hitting the pavement.

The second thing you can do is once you're in a slide, be smooth with the throttle. That means, do not chop it, which is of course the instinctive reaction. It's much easier said than done, but if you adhere to rule 1 above, you'll have a lot more time to do something if the bike begins to slide more progressively than if all of a sudden you give it a whole bunch of gas and find yourself sideways. So what should you do? You don't necessarily need to keep rolling on. More often than not, all that's required is to keep it steady. The other important thing is to not have a death grip on the bars, which you shouldn't do anyway.

So, stay loose and relaxed and be smooth on the throttle.

[SaloSV]

Originally posted by kiltwearinfool
A slide initiated by a road anomoly (gravel, oil, etc) is different than a slide initiated by a tire condition.




good point. without that information, i just assumed it was due to over throttling.

[NOTCH1]

Originally posted by Enchanter
Doing that will allow the rear tire to regain traction much more suddenly and abruptly. That could actually cause the highside if the rear tire is 'that' much out of line with the front tire.

thanks enchanter, sounds like grabbing the clutch would be the last thing you'd want to do. staving off the instinctive reactions is a tough one!

does the experienced MSF rider course include this as a hands-on exercise or would that just be too much heartbreak and mayhem?

[Enchanter]

Originally posted by NOTCH1

thanks enchanter, sounds like grabbing the clutch would be the last thing you'd want to do. staving off the instinctive reactions is a tough one!

does the experienced MSF rider course include this as a hands-on exercise or would that just be too much heartbreak and mayhem?


No. Almost possibly, getting close, but actually not highsiding is not practiced in the ERC.:p

Some highsides are caused by locking and then releasing the rear wheel when attempting to stop quickly. The old version of the ERC did have an exercise that invloved locking the rear wheel (at 20mph) and holding it/keeping it locked until the bike stopped. This would help riders learn to eliminate the panic reaction of immediately releasing the rear brake.

[cmoore04]

wow thank you so much for all your help. I really appreciate all this advice. My conclusion is that a road condition caused the initial loss of traction (aided by other things like too much gas maybe) and I guess the best thing I could do (besides being more cautious on certain roads) would be have more seat time so maybe I can feel the slip a little earlier and that way prevent the bike from getting so sideways I can't recover.
Thanks again for all the help and discussion. I think this site is a great arena for questions and help, as well as possible friends:teeth

[Enchanter]

Originally posted by cmoore04
My conclusion is that too much gas caused the initial loss of traction (aided by other things like a road condition maybe) and I guess the best thing I could do would be to try and be more cautious with the throttle.

I fixed your post because you must have inadvertantly gotten the primary cause and the secondary cause switched around.

[Hoologan]

You gotta be careful with all that horsepower that CBR1000cc RR puts out. :laughing

[cmoore04]

ya thanks, and I thought I was careful but now I'm gonna be extra extra careful, it's obviously not like my old 600.

[cmoore04]

and again you are right enchanter :)

[Zed10R]

Originally posted by Alexey
So, stay loose and relaxed and be smooth on the throttle.

Yup. I've had the rear of my bike slide out quite a few times. Being loose and controlling the throttle SMOOTHLY can made rear end slides a non event. You can't feel what the bike is teling you unless you are loose and smooth.

Good tires help a lot too....by good I don't mean Dunlop....:p

[cmoore04]

haha ok thanks

[tiptoezoomzoom]

try to brush off some speed with the front brake, yes, it's stupid, but I think a lot of new riders don't realize the different between slowly lowering the speed down by gently squeezing the front brake lever VS grabbing a handful in midcorner.

Try it. slow in fast out, and after 4-5 times you will feel more confident with speed control, especially with downhills.

[tiptoezoomzoom]

Originally posted by Zed10R
Yup. I've had the rear of my bike slide out quite a few times. Being loose and controlling the throttle SMOOTHLY can made rear end slides a non event. You can't feel what the bike is teling you unless you are loose and smooth.

Good tires help a lot too....by good I don't mean Dunlop....:p

Hey, I run 208gp in the hills and that shit sticks. Lower tire pressure down to 32/34 for aggressive riding and you'll see what I mean :finger :p

[cmoore04]

ok cool thanks tiptoe:thumbup

[Merricks]

Originally posted by Enchanter
No. Almost possibly, getting close, but actually not highsiding is not practiced in the ERC.:p

Some highsides are caused by locking and then releasing the rear wheel when attempting to stop quickly. The old version of the ERC did have an exercise that invloved locking the rear wheel (at 20mph) and holding it/keeping it locked until the bike stopped. This would help riders learn to eliminate the panic reaction of immediately releasing the rear brake.

I'm a pretty new rider and sometimes I do lock the rear wheel. I just can't seem to get a feel for it like I do the front. Anyway, if the rear wheel does lock, are you supposed to keep it locked or is there a method to releasing it (vs doing it immediately)?

[cmoore04]

ya from what I know (not much) keep it locked til you stop if you release the rear you will high side if you are not totally straight

[Alexey]

Originally posted by Merricks
I'm a pretty new rider and sometimes I do lock the rear wheel. I just can't seem to get a feel for it like I do the front. Anyway, if the rear wheel does lock, are you supposed to keep it locked or is there a method to releasing it (vs doing it immediately)?
What makes traction tough to gauge at the rear is weight transference in different conditions. Unlike when you apply the front brake, which almost inevitably transfers weight to the front tire, the rear can be pretty light, especially if braking with both ends. First and foremost, I'd recommend on working on the cause of lock-ups. Maybe you need more work on the front brake, maybe you need to adjust the rear brake lever position, maybe you need to work on being smoother with your right foot. As far as releasing the rear lock-up, hold it locked up until you're sure you're going straight. And, like I said before, stay loose on the bars, particularly whlie the bike is crossed up. If it wants to correct itself, you may be inhibiting that action by holding on to the bars for dear life. Hope this helps.

[Zed10R]

Originally posted by tiptoezoomzoom
Hey, I run 208gp in the hills and that shit sticks. Lower tire pressure down to 32/34 for aggressive riding and you'll see what I mean :finger :p

Different strokes for differnt folks, man. In my experience, ANY 208 tire in the dunlop range leaves me wanting more.....:teeth :p

[Merricks]

Thanks cmoore04 and Alexey. I think my problem is that I feel like I should be pressing the rear as hard as I'm squeezing the front (which I know is wrong). So I just need to practice being gentle on the rear, I think.

Your replies were very helpful. Sorry if I hijacked the thread a little.