parking lot slide

[Siris]

So I was working on my body positioning in a large empty parking lot yesterday. Making turns and putting most of my weight on my inside leg, knees out, chest facing into the center of the turn. Was doing relatively well and getting more comfortable as I pushed the lean tighter (to almost touching my knee down but that wasn't the objective), while keeping speeds around 25-35 mph.

Then on a right turn, my rear wheel slipped out (that's how it felt), and I low-sided when the bike and I began sliding. Never even touched the brakes the whole time. The bike must have slid 50-60 ft. I slid maybe 30-40 ft. Good thing I had my full leathers on. Knee sliders took brunt of the hit, followed by my forearms and back of my gloves. The bike had minimal damage too, with frame sliders, bar ends, brake pedal, passenger peg, and rear right spool slider taking bulk of the hit. Aside from straightening out the brake pedal, nothing else needed to be done. Minor rash on the sliders.

Post examination seemed to reveal that since I never had ridden on the edge of my tires, they were relatively brand new. Combine that with the bumps from the tar snake they used to seal cracks in the parking lot that may have destabilized
the bike, the relatively high rear tire pressure (34-35 psi) on stock Ninja 650 tires, and the result was the low slide.

I guess I should've known not to lean as much on a parking lot with so many raised tar snakes. I was feeling them earlier while riding but due to high temperature yesterday, I figured they would not be an issue. There were sprinkling of small rocks as well, and while they didn't contribute to this slide, they could've. Now I am going to be apprehensive every time I work on my body positioning in a parking lot and may take a while to get to the same level of comfort. I would never need to lean that much on the streets anyway (unless in an emergency), but wanted to see what was possible in a controlled environment.

The black stuff ain't coming out out of my leathers on my right forearm. Perhaps a good reminder to modulate limits based on environment.

Just wanted to share...not sure if this is the right category.

 

[HeatXfer]

Parking lots are dirty i.e: loose debris, oily spots, broken glass etc. you probably hit a nice patch of loose sand/dust or an oily spot.

I don't think a parking lot is the place to practice 'knee-out riding'. As well, 35mph in a parking lot seems a bit excessive to me. If you slid 40ft I'm pretty sure you were you were going faster than 35mph.

 

[dravnx]

The painted lines can be slippy er then snot on a doorknob.

 

[Kawikiwi]

The painted lines can be slippy er then snot on a doorknob.

Tar snakes too, especially when it's hot

 

[Siris]

Parking lots are dirty i.e: loose debris, oily spots, broken glass etc. you probably hit a nice patch of loose sand/dust or an oily spot.

I don't think a parking lot is the place to practice 'knee-out riding'. As well, 35mph in a parking lot seems a bit excessive to me. If you slid 40ft I'm pretty sure you were you were going faster than 35mph.

I figured if Lee Parks and so many other riders started by practicing in parking lots, that's a good precedence. Somewhere I read he actually worked on knee down in a parking lot. Maybe I just chose the wrong lot to practice on, my luck.

 

[DucatiHoney]

Moving this to Crash Analysis, since it seems that you're trying to figure out what went wrong. CA has specific rules, such as posts need to be focused on sussing out the causes leading up to the crash--not how the gear performed or the cost of the damages. Everything should be about determining what happened up to the point of falling over and/or what actions could have prevented it.

I'll start things off: Your guess of speed and of the sliding distances that you and the bike experienced don't seem to line up. Speed changes the forensics of the crash dramatically. How do you know what speed you were going? Did you look? How do you know how far you and the bike slid? Did you pace it out? Measure it? Spitball it? I've found that most people have no concept of distance. I'm an architect--I know a lot of people who think a bicycle is 3' long and their 8' ceilings are 10' tall.

 

[Siris]

Moving this to Crash Analysis, since it seems that you're trying to figure out what went wrong. CA has specific rules, such as posts need to be focused on sussing out the causes leading up to the crash--not how the gear performed or the cost of the damages. Everything should be about determining what happened up to the point of falling over and/or what actions could have prevented it.

I'll start things off: Your guess of speed and of the sliding distances that you and the bike experienced don't seem to line up. Speed changes the forensics of the crash dramatically. How do you know what speed you were going? Did you look? How do you know how far you and the bike slid? Did you pace it out? Measure it? Spitball it? I've found that most people have no concept of distance. I'm an architect--I know a lot of people who think a bicycle is 3' long and their 8' ceilings are 10' tall.

I was originally considering if this post should go under "General" or "Riding Skills". Didn't even consider CA as I knew what led up to the crash itself as described above from both what I was doing and the environment. Just wanted to share my first crash experience while improving on a specific skill (body position) and my learnings. But if this is more suitable in CA, that's fine with me.

As for discrepancy in speed/distance of the crash, its my own assessment. I had been riding around 25-35 mph doing the same thing for the last half hour or so. And while my eyes were nowhere close to looking at the dash, I was circumscribing about a 30 ft radius I would guess, in second gear, and not really pushing the bike very hard (below 5-6k RPM based on the feel of the bike). So I am guessing I was around 25-35 mph. I could've ridden in 1st gear even, but my bike is so choppy in 1st gear without feathering the clutch, wanted to keep things smooth. But this is all conjecture cause I was looking at the center of the circle I was tracing when this happened and not at the dash.

And I looked and guesstimated the distance of travel. I had someone helping monitor my body position too and he made similar estimate. I assumed because the lot surface was pretty smooth and the bike slid on frame sliders, and I slid on my leathers, the distances added up. But, I could be wrong .

 

[DucatiHoney]

Are you sure you didn't just catch a peg? Maybe there was a little oil on one of the tar snakes? Did you go back and look? I don't see you exceeding tire traction at such low speeds. What would you do differently? There's no learning from this if you don't walk away with the situation just shrugging your shoulders.

 

[Siris]

Are you sure you didn't just catch a peg? Maybe there was a little oil on one of the tar snakes? Did you go back and look? I don't see you exceeding tire traction at such low speeds. What would you do differently? There's no learning from this if you don't walk away with the situation just shrugging your shoulders.

I checked the peg. Didn't see much damage there. And at the lean I was maintaining, I really didn't think I would slide out. The only thing I can think of was that the edge of the tires were not scrubbed at all and combined that with the bumpy tar snake and high tire pressure, it destabilized my bike, and I must have tried to compensate by shifting weight (which I am not aware as it happened very fast), and so my rear wheel lost traction and I went down.

I guess under this scenario, if I had to go back to do it again, I could've hung off more so I had the bike standing more vertical. Also support my body more using my legs and more weight off handlebars, so bumps and slips won't transfer to my hands to handlebar to further destabilize the bike.

But bigger learning as I mentioned in the original post is probably to be more cautious of my environment. I had my GoPro camera on my helmet, forgot I had it turned off. Too bad. Would've been nice to have the footage.

 

[Gary856]

35 psi doesn't sound that bad but how much do you weigh?

Where was the parking and how was the surface texture? When I tried to find a good parking lot for practice, I noticed many of them had a pretty smooth surface texture and didn't seem to provide good traction at high lean angle. I wonder if street pavements need to meet some kind of texture/traction standard, and whether private parking lots are subject to the same standard.

Lee Parks' classes sweep the parking lot and ask students to lower tire pressure to 30 psi. I assume they pick parking lots with good surface (traction) too. He makes knee down in the parking lot look like a walk in the park.

 

[Siris]

35 psi doesn't sound that bad but how much do you weigh?

Where was the parking and how was the surface texture? When I tried to find a good parking lot for practice, I noticed many of them had a pretty smooth surface texture and didn't seem to provide good traction at high lean angle. I wonder if street pavements need to meet some kind of texture/traction standard, and whether private parking lots are subject to the same standard.

Lee Parks' classes sweep the parking lot and ask students to lower tire pressure to 30 psi. I assume they pick parking lots with good surface (traction) too. He makes knee down in the parking lot look like a walk in the park.

About 150 lbs. The lot I was practicing on is pretty smooth versus actual road texture which are more rougher. I actually got down and felt the difference with my hand. I notice my tires chirp more at the end when I do emergency braking in parking lots versus on an empty road.

I agree about the lean angle on parking lots. I don't think I will be leaning as much. I will just work on various stuff, including body positions and such, but without actually leaning the bike over as much.

 

[tzrider]

Sirius, how were you doing the exercise? Were you riding in circles or riding straight and then entering a turn? Any input I can give may depend on knowing that.

 

[Siris]

Sirius, how were you doing the exercise? Were you riding in circles or riding straight and then entering a turn? Any input I can give may depend on knowing that.

I was already riding a circle at a specific lean when I lost the bike.