Cornering Theory (split from High side thread in Crash Analysis)

[Yoshiro]

MOD EDIT: Original thread here:http://www.bayarearidersforum.com/forums/showthread.php?t=231953

Bike: 04 ZX6RR with Dunlop Sportmaxx GP
Story: I had previously known the Dunlop Sportmaxx GP were slick without proper warmup. But i keep forgetting that when i startup the bike. I'm taking a right turn out of a parking lot and accellerate mid turn. the turn was about 80% complete. The rear tires spin and i lose traction as the rear end swings out. At this point i dont remember if i hit the brakes or let go of the throttle. The bike fishtails 3 times and it throws me out in front of it.
Speed: approx 15-20mph
Bike Damage: windshield mainstay, windshield, both mirrors, front fairing, right fairing, right seat fairing, cowl cover, both rearsets bent, front and rear master brake snapped, handle bars tweeked, tank dented on right side, right hand lever broken, right Sato frame slider shattered and broke off, taillight cracked
Human damage: skin rash on both knees, right hip, right elbow, one hell of a sore right shoulder and neck. Helmet and jacket has nicks

What should i have done?

 

[NoQuarter]

I rarely read this section of the forum, but I found this thread interesting. Throttle control and being aware of the conditions are both extremely valuable skills to have. To focus all the blame on one or the other is a mistake. You never know exactly how much traction you have until it starts to slip, that's just how it is. The skill part of that is being able to control the slippage. Sometimes we simply get caught out, it happens too fast and too unexpectedly. Buying a smaller bike or riding slow in parking lots wouldn't solve your problem. It'd simply reduce the chances of breaking traction by minimizing the available circumstances in which the throttle could over power the rear tire. (oiling the surface would do that in a hurry however, again demonstrating that conditions have just as much influence as actions)

What to do? Practice sliding (easily and fairly safely done with small dirtbikes on flat surfaces)

Assuming you keep the same bike, follow the advice and get proper street tires. Would that have made a difference in this case? Maybe, maybe not. But good street tires are designed for a broader range of conditions by far, therefore increasing the available margin of error. (And that's advice from a racer, because I don't bother reselling my take off's to street riders.)

My general advice is to study all the factors that contributed to the crash. If it were simply 100% about the rider's throttle control ability, why do we see far far many more MotoGP guys crashing in the wet versus the dry? Certainly their throttle control doesn't change suddenly. No, it's simply that the conditions become less predictable, the margin for error much smaller.

 

[Holeshot]

...and they've not got traction control on the front tire, Dave!

Dave's spot on. The correct answer is the recall what happened with your throttle hand. To regain traction, a rider needs to dial back some throttle (or at least not advance it) and pick the bike onto the tire. It sounds as if you carried too much lean angle for the dynamics of the day. We don't NEED as much lean angle to turn the bike at slow speed..and 15-20 is slow.

 

[stangmx13]

ok im lost. ive been in 2 situations myself that sound similar to here.... but im not sure which one is correct esp w/ the "fishtail" description floating around.
#1 - left my work parking lot after my shift late at night, leaned the bike over too far, attempted to compensate w/ the throttle and went down at 5mph
#2 - taken a turn i kno quite briskly, lost the rear tire a bit, stayed steady on the throttle w/ my weight to the outside, the bars did 2-3 full tank slaps and the bike settled by itself

sounds like #1, but the "fishtail" just reminds me of #2... maybe a combination of both. however, the solution to both situations (other than obviously riding smarter) are completely different. so which one?

 

[Enchanter]

ok im lost. ive been in 2 situations myself that sound similar to here.... but im not sure which one is correct esp w/ the "fishtail" description floating around.
#1 - left my work parking lot after my shift late at night, leaned the bike over too far, attempted to compensate w/ the throttle and went down at 5mph
#2 - taken a turn i kno quite briskly, lost the rear tire a bit, stayed steady on the throttle w/ my weight to the outside, the bars did 2-3 full tank slaps and the bike settled by itself

sounds like #1, but the "fishtail" just reminds me of #2... maybe a combination of both. however, the solution to both situations (other than obviously riding smarter) are completely different. so which one?

The answer is #3: Ride smarter. Seriously.

You are riding too close to the edge of available traction. If you keep doing this type of riding, it is going to end in another crash.

 

[stangmx13]

The answer is #3: Ride smarter. Seriously.

You are riding too close to the edge of available traction. If you keep doing this type of riding, it is going to end in another crash.

this answer is in no way relevant to my questions. i kno exactly wat caused both problems, my error. but i want to kno how these situations apply to the OP and wat everyone else has been saying. also, those were not in any way recent situations/errors.

 

[Enchanter]

this answer is in no way relevant to my questions. i kno exactly wat caused both problems, my error. but i want to kno how these situations apply to the OP and wat everyone else has been saying. also, those were not in any way recent situations/errors.

Sorry, I guess I do not clearly understand your questions. If you are looking for a way to not crash once you start to loose traction, there are some techniques that might help. Let's discuss those in the Training Forum.

If you are looking for ways to avoid loosing traction in the first place, then the answer is to find the proper balance of speed, lean angle, and throttle position. These are simple words to write, but very tough to define an actual hard and fast 'rule'.

It all comes down to how close we want to ride to the actual limits of our skill, the limits of or motorcycle, and/or the limits of the environment. I learned a long time ago that I want a buffer zone between what I want to do, and how much of what I want is too much. On the street, I personally try to ride at 70-80% of what I think is available. I want a fairly large safety or buffer just in case I encounter something I wasn't expecting. That something could be a car, a bicycle, an animal, or a loss of traction.

 

[RhythmRider]

ok im lost. ive been in 2 situations myself that sound similar to here.... but im not sure which one is correct esp w/ the "fishtail" description floating around.
#1 - left my work parking lot after my shift late at night, leaned the bike over too far, attempted to compensate w/ the throttle and went down at 5mph
#2 - taken a turn i kno quite briskly, lost the rear tire a bit, stayed steady on the throttle w/ my weight to the outside, the bars did 2-3 full tank slaps and the bike settled by itself

sounds like #1, but the "fishtail" just reminds me of #2... maybe a combination of both. however, the solution to both situations (other than obviously riding smarter) are completely different. so which one?

I'm not sure what you're asking. However, I do agree with Enchanter that you need to be more aware of your available traction if you want to avoid further "situations." Do you know about the traction pizza?

 

[NoQuarter]

I'm not sure what you're asking. However, I do agree with Enchanter that you need to be more aware of your available traction if you want to avoid further "situations." Do you know about the traction pizza?

While this is true, the big question is: how do you know what the traction is? To even target 70-80% of maximum available is to know what the maximum is. The only way to do that is to actually break traction in the given situation. Not something you can safely put into practice on the street in normal riding because every situation is unique. Unless you constanty turn around and re-ride a given turn over and over again. (which is exactly what you do on a track, therefore making it far easier and safer to test the traction limits)

I had a very similar accident about a year after I started riding leaving my workplace parking lot. I'd done the same exit in the same manner dozens of times before, winding up first gear so I could listen to loudass D&D pipe reverb off the overpass above...woohoo! aren't I badass! of course, the day came when that same input from me resulted in a 20mph highside? why? because the road was a bit damp in the shade from the earlier fog and I didn't account for it. That was a long time ago, before I knew hardly anything about bikes. But even then, I came to the obvious conclusion that just because something's worked everytime before, conditions change and I need to be aware of that every time I roll off.

I really still only see 2 things that'd help you avoid repeating this crash in the future, get some practice sliding on two wheels (in the dirt is easiest) and mount up some street tires that are designed to operate over the much broader range of conditions found when street riding. The first will help you deal with it when it happens, the second will increase the safety margin for preventing it.

cheers,

 

[stangmx13]

I'm not sure what you're asking. However, I do agree with Enchanter that you need to be more aware of your available traction if you want to avoid further "situations." Do you know about the traction pizza?

wat pizza??

i guess my question was a little unclear. i meant to ask which of my situations is the same as/similar to wat the OP described... kinda of need to kno that to fully grasp was everyone else is saying. im not exactly a newb to riding, and obviously situation #2 shows a bit more experience than #1, but ya always room to learn more. those were prob both about 2yrs ago.

While this is true, the big question is: how do you know what the traction is? To even target 70-80% of maximum available is to know what the maximum is. The only way to do that is to actually break traction in the given situation......

good pt... and yet the only way ive been able to break traction at the track is running wide onto the curbing, which sadly had a bit of dirt on it. lame.

..... I really still only see 2 things that'd help you avoid repeating this crash in the future, get some practice sliding on two wheels (in the dirt is easiest) and mount up some street tires that are designed to operate over the much broader range of conditions found when street riding. The first will help you deal with it when it happens, the second will increase the safety margin for preventing it.

cheers,

the consequences of sliding on dirt are much much less than on the street... making slides fun on the dirt and scary/dangerous on the road. plus the weight issue really bothers me, much easier to slide both tires on a 220lb dirtbike than even one on a 400lb sportbike. also, i really dont think a set of tires exists (other than race rains) that would prevent our subsequent low speed crashes. its all rider error there

 

[Zachary]

Sorry to get all simple,

but has anyone mentioned one of the very basic pieces of motorcycle advice, the part where you keep a steady throttle in a turn? You dont brake, or accelerate in turns.

 

[Zachary]

Sorry to get all simple,

but has anyone mentioned one of the very basic pieces of motorcycle advice, the part where you keep a steady throttle in a turn? You dont brake, or accelerate in turns.

 

[Archimedes]

but has anyone mentioned one of the very basic pieces of motorcycle advice, the part where you keep a steady throttle in a turn? You dont brake, or accelerate in turns.

I think you mean 'accelerate smoothly through the turn'. You sure don't want to keep a neutral (i.e. steady) throttle through a turn. You want to be progressively opening the throttle through the turn.

 

[Zachary]

yeah

Sorry, I wasnt very clear. Never brake HARD, or accelerate HARD out out of a turn. Steady like no sudden bursts.

 

[My900ss]

I think you mean 'accelerate smoothly through the turn'. You sure don't want to keep a neutral (i.e. steady) throttle through a turn. You want to be progressively opening the throttle through the turn.

While racing sure, leaving a parking lot no. The following are not my words though I found them on the internet so they must be true

The one thing that you don't want to do when your bike is leaned over is dramatically change your speed. This will upset the balance of the motorcycle and could cause you to loose traction. Most motorcycles can accelerate, turn, and stop extremely well. They just don't like to do more than one of them at a the same time.

http://www.motorcyclebasics.com/curves.htm

 

[27007RT]

umm in reality Sportmax GPs ARE NOT street tires.

I disagree entirely. I've been running my "worn out" track tires on the street - after I burn off the edges my 209 GP's and NTEC's they have thousands of miles left on the center tread. In fact, I've been riding them in the rain and they have done GREAT despite their lack of water shedding grooves.

As far as the highside, I find the 209's warm up faster and stick faster than a street tire. I'm sorry to hear about your accident. Did you look in the roadway for anything that may have caused your crash?

I did a 25mph highside leaving a golf course parking lot once - I went through water, the back end stepped out and I was on the ground. I walked back to the water and found it was actually mud from the golf course. When the back end slid, I chopped the throttle and that was that.

 

[Archimedes]

While racing sure, leaving a parking lot no. The following are not my words though I found them on the internet so they must be true

The one thing that you don't want to do when your bike is leaned over is dramatically change your speed. This will upset the balance of the motorcycle and could cause you to loose traction. Most motorcycles can accelerate, turn, and stop extremely well. They just don't like to do more than one of them at a the same time.

http://www.motorcyclebasics.com/curves.htm

You might want to do some more research. Perhaps read Code's stuff. You surely don't want to wack the throttle, but from the instant you lean the bike, you want to be accelerating smoothly and progressively through the turn. This holds true anywhere you're riding, street or track. You do it smoothly so you don't upset the suspension, but you definitely open it. Anyone who is running neutral throttle through a turn is making a mistake. (unless you're preparing to brake or have visibility issues).

The change in tire diameter alone when you lean your bike over will slow your bike at a given throttle position. If you don't open the throttle, you will actually slow down.

From the master himself: "Begin to roll-on the throttle as soon as possible-ideally, right after steering-and continue to roll-on smoothly through the turn. If you can't roll-on immediately and must scrub off more speed, your entry speed was too high."

 

[Holeshot]

I think what happens to alot of street riders in crashes like these are they ADD lean angle past the apex of any given turn, and many times, add throttle at this point...remember, as you add throttle, begin to pick the bike up OFF the side of the tire...dont' ADD more lean angle.

 

[tzrider]

I think what happens to alot of street riders in crashes like these are they ADD lean angle past the apex of any given turn, and many times, add throttle at this point...remember, as you add throttle, begin to pick the bike up OFF the side of the tire...dont' ADD more lean angle.

Bingo. And the phenomenon of adding lean angle after the apex is usually the result of having turned too early or pointing the bike at too early an apex. Rider finds himself going wide and tightens his line a bit. If you've got to tighten your line, then you do, but that's not the moment to be stretching the throttle cables.

I can't say whether this applies to the OP's situation, but he can benefit from really getting the relationship between throttle action and lean angle that Berto is talking about.

 

[Enchanter]

You might want to do some more research. Perhaps read Code's stuff. You surely don't want to wack the throttle, but from the instant you lean the bike, you want to be accelerating smoothly and progressively through the turn. This holds true anywhere you're riding, street or track. You do it smoothly so you don't upset the suspension, but you definitely open it. Anyone who is running neutral throttle through a turn is making a mistake. (unless you're preparing to brake or have visibility issues).

The change in tire diameter alone when you lean your bike over will slow your bike at a given throttle position. If you don't open the throttle, you will actually slow down.

From the master himself: "Begin to roll-on the throttle as soon as possible-ideally, right after steering-and continue to roll-on smoothly through the turn. If you can't roll-on immediately and must scrub off more speed, your entry speed was too high."

So where does that leave trail braking? Are you saying that trail braking is wrong and should never be used?