What happened- My Highside Crash

[Jaybird180]

I'm looking for clues, analyses and helpful information. I am not hurt and the bike (hopefully) can be rideable again in short order using a few bolts and copious quantity of duct tape to get me through the remainder of the year, then I'll properly rebuild over the winter.

I should also make it known that the crash sequence has been edited and isn't gory or graphic. The raw footage wasn't gory either, but I edited it to purposely take some of the potentially emotional impact away from viewers, so we can focus on forensics.

 

Edited October 12, 2017 by Jaybird180
Note about footage editing

[Lnewqban]

Sorry to see that happening.

It is hard to tell from that point of view and sound only.

The engine can put a lot of torque on the rear wheel while in third gear.

Could it be that inadvertently you applied excessive throttle, which made the tire break loose?

[playersnoopy]

Hard to tell of course; but since it's in the rain and judging from the sound that little bit of throttle could have cause the initial loss of traction causing the rear to slide out then the high side is when the rear regains traction and from the rain it's not hard to go from slick to a spot it can grip once again when the throttle is cut.  Even if you maintained the throttle during the slide the wet track would have helped cause the high side; one escape would be to throttle more and keep the rear sliding and bring traction back slowly... easier said then done of course   I have a wicked slide on wet roads a little while back on the streets where I was a little abrupt on the turn but held the throttle and just slide all the across through the turn (luckily no oncoming traffic) and kept riding on; the video is helmet mounted and hard to tell what's going on in mine except you see me go from one side of the road to the other as I'm in the turn.

Jaybird... you're in my neck of the woods... have we met out here?

[Jaybird180]

@Playersnoopy- I don't know if we've met but I'm open to it if we haven't. I'm going BACK to NJMP on 28-29th if that matters to you.

From my recollection and from what I can ascertain from the video the RPM rise occurred when the tire broke loose. I felt the rear end come around and I intended to hold steady throttle, but when I got launched, all control had been lost. 

I've let others view the video and they've said it's a greedy right hand that caused the break in traction. Although I'd been working on improving my exit drive I'm an extra cautious guy...heck I might post a dry video just to show how "genteel" I usually get on the gas. 

[Jaybird180]

What I know sofar:

The limit of rear traction was exceeded and continued to be exceeded throughout the crash sequence. I'd experienced a lot of little slides in various places around the track. Traction seemed to be better when the rain was steady and harder than it was with the light precipitation. In many of the curbings, including this final turn there was standing water. Professional races are not conducted when there is standing water on the track surface, which means that perhaps discretion was better than valor this day?

What the video doesn't show:

The rear end coming around before I was ejected

What is yet unknown

Was the throttle rolled on to make RPM go from 6500-8000 or was it the loss of traction?

[Jaybird180]

Many of the people I've asked to review the video have said that it's a greedy right hand causing the crash. I'm not convinced this is the case here. And here's why: The video doesn't show the moment the rear end comes around thereby ejecting me from the bike. It's difficult to ascertain if the rise in RPM came from my throttle hand or the loss of traction allowed the engine to spin more freely, thereby causing the rise in RPM but I believe the latter. This bike doesn't have data log capability, otherwise it would be easy to download the data and look at TPS log. and compare with RPM log.

Turn 14 has a very slight rise to it, which SHOULD have contributed to improved traction and I wasn't in the standing water in the curbing. From the video is looks like the turning had been completed and attention was on the exit phase when a roll-on would have been appropriate. It is during the roll-on that there was a sudden and marked change in RPM and I believe that I held the throttle steady during the sequence with the hope that traction would return same as other slides experienced (okay, okay, I admit...my hand and arm was frozen like a butterball turkey on November 20th when the rear came around and when I realized, my mind was then commanding: "Relax"). From viewing footage of other prior turns, it doesn't indicate a habitual abuser of the throttle. That's my case and I'm seriously looking for answers, I know this is the rider's fault, IT'S ALWAYS THE RIDER'S FAULT. And this rider is looking to make corrections.

[faffi]

Note that I am miles from any kind of an eggspert, so do not put too much weight on what I'm typing. However, having watched the video several times over, this is what I noted:

- Could it be that you apply throttle like a stepper motor? Several places during the video, it sounds like the engine goes eh-eH-EH-EEHH in steps instead of gaining speed gradually, like you would expect with a smooth and even continuous throttle application. This could of course be down to your engine's natural response and/or the sound pickup.

- It seems like you apply throttle a bit eagerly just before you crash, making it sound as if the rear is spinning up. Then the rear begins to overtake you, and you give it more throttle, likely a result of being whacked by the bike and not a willed reaction. My guess is that you came on a little strong on the throttle just as the rear wheel was on a slick patch, either from extra standing water or something with the surface itself. So a combination of poor timing due to bad luck as these things can be impossible to spot in the wet.

The good thing is that you are OK. And you also shout NOOO much shorter than me - I keep going 

[playersnoopy]

5 hours ago, Jaybird180 said:

The limit of rear traction was exceeded and continued to be exceeded throughout the crash sequence. I'd experienced a lot of little slides in various places around the track. Traction seemed to be better when the rain was steady and harder than it was with the light precipitation. In many of the curbings, including this final turn there was standing water.

That would normally be the scenario; consistent road/track conditions regardless of if it's rain or not is better... we know we can ride in the rain and wet roads just a little slower and less abrupt inputs.  With light precipitation there could be slicker parts which would be a similar situation to say riding in normal conditions with a slick patch.  So yes you could have been in a spot that's a little less wet and have a little more traction followed by a patch of water and lose traction which started the whole mess.

Jaybird - I don't go to the track except for the days at CSS; I ride mainly street usual group rides with the MD groups here.

[Jaybird180]

I think my answer is in Ch 13 TOTW-2.

Recently I attended Cornerspeed and one of the takeaways that restates the sentiment in Ch13 is to think of the motorcycle not as a bicycle with an engine but think of it as a unicycle with an engine. For me this means that I asked too much of the rear on a compromised surface. It's the only logical choice.

[Lnewqban]

Carefully observe the hand and steering inputs of the rider in this vid, as well as how the rear tire reacts to those inputs (or lack of them).

Keeping traction of front tire and torque flowing onto rear allows command of rear tire regarding returning to proper alignment.

Just like needed for proper braking, the transfer of weight towards the rear should happen prior the contact patch receives the additional torque from the engine. The transfer takes some time and it can only be initiated by moderate throttle, which can be increased progressively as rear traction improves.

That smooth initial throttle is hard to achieve in bikes with fuel injection and lacking traction control aid.

 

https://m.youtube.com/watch?v=H93kPnDQEqA

 

[Jaybird180]

I will study it with vigor!