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Tires un-glue from road in a turn - what then?


EddyQ

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I spent some time reading throught the post from Perlova (poor guy that lost it with a new set of roadsmarts) and it was the second guy this season that I know who had the same issue. I haven't had any issues like this, but obviously folks are not aware of something here.

 

The thread hit hard on what folks should know about tire traction. Many also said good technique may have made a difference. I am no athority here, so could some of you help me out??

 

Based on some limited dirt riding experience, it was good to keep on the gas when the rear kick out. Steer towards the skid. Typical instinct would cut the gas resulting with engine breaking and lack of side thrust that would worsten the situation.

 

Is this the proper technique for an RT that kicks out?? Maybe due to new tires or cold weather or even sand.

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I'm sure the Guru's will chime in soon. But I think that you are on the right track.

If I were in that situation (and have been) just stay on the throttle (NO more poss. SLIGHTLY less) and you should self correct when traction is again possible.

Although all situations are different this is what I would do for a MOMENTARY loss of traction.

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I have had two sets of Roadsmarts, neither have done as you had mentioned. And for those who know me know that i ride aggressively in the curves. There are factors that would let this happen to all tires based on environmental conditions. Like tire/road temps, the type of road surface (AKA coefficient of friction) and the overall road condition to include the crown angle.

 

Your ability to steer out of the scenario seems correct and there are factors there too. Speed, bike geometry and the like all play a role. Let's pray nobody has to deal with this in the near future. It can get the pucker factor past the 10 mark.

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Certainly maintain the throttle, but it's better to have the tire spinning faster than slower, as the rotational inertia of a spinning tire adds to stability.

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The few times I've had the rear step out, I've instictively eased up on the throttle and steered accordingly (countersteered) to maintain "balance".

 

I haven't had the guts to intentionally get on the throttle exiting a corner on loose surfaces to see how much the ASC would kick in and correct it. It does work pretty well in a straight line.

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For those unfamiliar with ACS (as I was 2 minutes ago):

http://www.webbikeworld.com/BMW-motorcycles/bmw-abs-asc.htm

 

ABS and ACS sound like they will prevent burnouts and locked-up skids as long as the tire is moving in a forward direction -- exactly what's not the case when the rear steps out. And for all the good they do, they still don't correct your trajectory/geometry once your rear wheel is stable.

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russell_bynum
I'm betting that more often than not by the time you know you lost traction you are already on the ground. Now you have it, now you don't.

 

It depends.

 

Sometimes it is gradual and easy to deal with. Sometimes it's quick.

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I'm betting that more often than not by the time you know you lost traction you are already on the ground. Now you have it, now you don't.

 

My experience has been opposite. More often than not, ending up on the ground is the result of abrupt maneuvering, overcorrecting, and/or chopping the throttle. It also makes a big difference whether the front wheel or the rear wheel breaks loose.

 

A loose rear wheel is not that big of a deal. A loose front wheel isn't necessarily the end of the world, but it's a lot harder to deal with. A front wheel slide can often be saved by throttle application.

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Always do surface appraisal to prevent the scenario from happening in the first place.

There are constantly changing variables in the coefficient of friction. In a non-track environment you should never ride in the 10/10th's zone where you are at the razor edge of traction and no traction. Stay away and you will never have to decide what method is best to recover from a skid. A side skid on a bike is never good and the correct action to take will probably be too late anyway.

All you need to do is look at footage from road races. It either ends with the rider low siding or high siding.

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I'm quite sure getting the tires to skid are not in most of our plans, but it will likely happen to all of us sometime down the road. Maybe we wasn't paying attention as usual or riding a new bike. If the bike kicks out and drops on its side instantly, there isn't much chance to save it and the next action might be related to what you're gonna hit. But I'm sure there are many occations where you will get some feedback in time and you will have a chance to do something. You will do something, correct??

I've had my old virago in a skid twice and when I think back, seconds seem like forever. Scared the hell out of me, but I managed to save it both times.

 

I think I'd like to add to the technique. Stand up off the seat. That will help balance and might prevent you from getting tossed off the bike when the tires re-grip the pavement.

 

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Originally Posted By: tlc

My new RT has ASC, so I don't worry about what to do......

 

 

That is an exceedingly bad plan.

 

 

_________________________

Russell

 

When Dr. David Banner gets angry he turns into the Hulk. When the Hulk gets angry he turns into Chuck Norris. When Chuck Norris gets angry he turns into the Stig.

 

+1, It most certainly is a very bad plan!

 

Gil Horsley

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russell_bynum

I think I'd like to add to the technique. Stand up off the seat. That will help balance and might prevent you from getting tossed off the bike when the tires re-grip the pavement.

 

If you know you're about to slide, then I'd agree that standing up and going into dirtbike mode is probably a good idea. But in the middle of a slide, I think that trying to stand up would not be a good plan.

 

Most bikes aren't setup so that you can stand easily from the normal seated position without sliding forward (or backwards, but usually forward) and/or using the bars for stability/support.

 

 

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Let's put it this way -- I'm over 60, and I finally had to admit that my reflexes ain't what they used to be. That, however, is not a bad thing. I have found myself in several situations where I did not "have time" to react, and I did nothing. After thinking about it later, I believe I would have been in more danger if I had tried to react. If the bike can help me out, that's just fine with me.

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I agree, with quick reflexes, you can catch subtle lateral wheel movements and correct for them pretty fast... font or rear. I've only lowsided on my MTB, but rode it to the ground each time.

 

Just watch some motorcycle racing, it's very possible to be sliding the tires and still stay upright. It's just a matter of maintianing balance and anticipating the loss of traction.

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Hitting transmission fluid while fully leaned over... What you do is go get some stitches in your elbow because you are an idiot and did not have on your armored jacket. Well at least thats what I did when the front went away on me. It really does depend on the situation and every one is different but I will say if you have to go down let it be a lowside and get the bike away from you if you can.

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I'm betting that more often than not by the time you know you lost traction you are already on the ground. Now you have it, now you don't.

 

It depends.

 

Sometimes it is gradual and easy to deal with. Sometimes it's quick.

 

You're right. It's happened to me both ways in the mountains around here and, with slight throttle application, I'm still here....or very lucky...or both.... :eek:

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  • 2 weeks later...

I think a lot of it depends on the difference between the grip sliding and the grip rolling and how close you were to the limit. If you are cornering street hard at 75% and lose 20% of your traction from a minor road imperfection, you can feel it drift but odds are good you will have enough time to save it. If you lost 70% it would be over quickly regardless of your skill level. Now if you are cornering at 95% and lose 20% traction your odds are much lower. This is why you should never corner close to the maximum on the street, those pavement imperfections are everywhere. Save it for the racetrack, with soft race compound tires where the coefficient of friction between rolling and sliding is not much different and the road surface is uniform.

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Since I just dumped my '06 RT two days ago in a skid I'd thought I'd chime in here.

 

I was out riding (with full gear and helmet) when I came upon some road construction with one lane closed. I waited for my turn to pass through. As I got into the single lane it turned to dirt then mud, then mud with water on top of it and then the terrain became uneven. Not a situation I would have chosen to ride through but at this point I'm committed.

 

I'm in 1st gear moving very slowly when my rear tire slides. I counter stir into the direction of the skid and the bike comes up straight. I tell myself to relax and keep moving forward. Within two seconds the rear tire starts to slide again on the "slippery slope" I'm riding on. As I counter steer again my hand puts on more throttle as I'm trying to hold the bike up. At this point my bike does a 180 and goes down. I slide through the mud for a few feet and come in "safe" in the middle of the road. The road was so slippery that it was all I could do to stand up without falling. Some guys helped me right the bike and I had to ride back the way I came (still sliding) to get out of the mess. I scrapped the crap out of my left side bag cover and had mud stuck on me and the bike on the entire left side.

 

Overall, I got off easy as did the bike. Not sure what I could have done differently except to avoid the construction zone all together. I couldn't tell how bad it was until I was in the middle of it.

 

 

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Loosing the front end is down right frightening. My 99 Rt tends to push the front tire when riding hard into tight corners and while it is fairly perdictable it always makes the hair on nape of my neck stand up. The rear tire breaking loose is not nearly the same level of worry.....and can even be a little bit-o-fun. In any case a 600 lb motorcycle isn't something I look to fliging around like a dirt bike, as once you get out of shape there is a good chance you won't be able to save it.

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Not sure what I could have done differently except to avoid the construction zone all together. I couldn't tell how bad it was until I was in the middle of it.

BTDT! Was there a flagman directing traffic at the start of the construction zone going into one lane? If so, don't be afraid to tie up traffic for a few seconds and ask the person what the road conditions are ahead. Or, if no one is around to ask, don't be embarrassed to turn around when conditions deteriorate and go back the way you came before the mud hits the fan. Also, I noted you said you were in first gear. You would be better able to handle the slippery stuff in second gear, along with slipping some clutch to bleed off extra torque when it's not needed. These steps will reduce freewheeling torque for the rear tire to deal with, thus less chance of starting a rear wheel spin. Less chance of starting a skid from engine braking when throttle is suddenly reduced on slippery surfaces, versus a spin from too much torque. Just my 2 cents...

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Not sure what I could have done differently except to avoid the construction zone all together. I couldn't tell how bad it was until I was in the middle of it.

BTDT! Was there a flagman directing traffic at the start of the construction zone going into one lane? If so, don't be afraid to tie up traffic for a few seconds and ask the person what the road conditions are ahead. Or, if no one is around to ask, don't be embarrassed to turn around when conditions deteriorate and go back the way you came before the mud hits the fan. Also, I noted you said you were in first gear. You would be better able to handle the slippery stuff in second gear, along with slipping some clutch to bleed off extra torque when it's not needed. These steps will reduce freewheeling torque for the rear tire to deal with, thus less chance of starting a rear wheel spin. Less chance of starting a skid from engine braking when throttle is suddenly reduced on slippery surfaces, versus a spin from too much torque. Just my 2 cents...

 

Thanks Greg. There was a flagman there and next time I'll know better and ask about the conditions. Totally agree with you that 2nd gear would have been a better choice than 1st gear. The rear of the bike was sliding based on throttle being applied on or off. Chalk it up to an AFGE (Another ----- growth experience).

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I think a lot of it depends on the difference between the grip sliding and the grip rolling and how close you were to the limit. If you are cornering street hard at 75% and lose 20% of your traction from a minor road imperfection, you can feel it drift but odds are good you will have enough time to save it. If you lost 70% it would be over quickly regardless of your skill level. Now if you are cornering at 95% and lose 20% traction your odds are much lower. This is why you should never corner close to the maximum on the street, those pavement imperfections are everywhere. Save it for the racetrack, with soft race compound tires where the coefficient of friction between rolling and sliding is not much different and the road surface is uniform.

 

I gotta get me one of those "gription percentage meters' so's I know how much I got left! :/

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