4/19 Chicane Trackday

[Player 2]

You're right Gramps

Usually I can look back and figure out what happened though. That year at the Gap I was just trying to ride harder than I could handle.

This time....

[rforsythe]

I disagree. You're making the assumption that the forks compress based on where the fork & wheel are as compared to the bodywork

Well yes, visual references are key here. That wasn't an assumption, the forks compressed.

but when the rear broke loose, the rear suspension would've decompressed as well, giving the illusion that the front was compressing. If you watch again, you'll see that the "compression" of the front forks happens at the same time that the rear is swinging around.

The front compressing is not an illusion here. I did watch it again (in addition to the 20 or so times I replayed it before), the forks compress just before the back comes around. Before that I think it's just the bike leaning that gives the appearance of shenanigans.

I've tucked the front and saved it, tucked the front and lost it, and lost the rear. IMHO, this was definitely the latter - the bike just goes down in different directions for each.

Right. He lost the rear because the front was compressed, which transferred weight forward thus lightening the rear wheel, causing it to break traction and send Jon ass-skating. Please note I'm not suggesting he tucked the front here, just that the mechanics going on with the front end caused a loss of rear traction.

It still doesn't answer why it happened, and what you said ("the lean put you at the max of your available friction...") is still accurate.

I think we're at about the max of whatever conclusion we're likely to sort out on this one. Turn 2 just likes to eat bikes in weird ways; I don't know if the asphalt there has deceptively low traction that cold tires just suck on or what (though I can guarantee there wasn't anything spilled out there). Tire warmers and braking before leaning will prevent it in the future, at least IMO.

I know it doesn't really make any sense, but any chance that building heat on one side of the tire robs the other side of heat (in the case of a cold, used race tire)? Jon was taking it easy, but he just came out of a long right-hander...

Not in the span between 1 and 2; however he didn't actually have any heat in the left side of the tire as it was the first lap, so that side of the tire was basically as it was when he left the pit plus whatever minimal benefit he got from the carcass flex. If any heat transfer were taking place between sides it'd have worked to his advantage in this case.

One thing I haven't seen mentioned here - what were the pressures F/R set to? Especially with cool tires that can make a huge difference. Assuming they were at least close to correct since the bike had gone out the session before, but I'm just wondering.

[Player 2]

28 /22

[eklew]

If they were Michelins, we were all running 30-31/22-23 for that day.

[Player 2]

I went with 28/22 on the advice of Rybo

[Bashed]

Also I heard you were on race takeoffs? Those will need extra time to warm up, especially when the track is cool. At Pueblo that's usually a couple laps for me unless the asphalt is quite warm to the touch. As it was cool on Sunday, you had near zero heat in the rubber by turn 2 on the first lap, so it would take almost nothing to get it sliding.

I was on old race tires as well and was spinning up the rear coming out of 4 and 10. This was in the afternoon after the track had warmed up considerably. Caution was in order for sure and I try and ease into the sessions progressivly picking up speed. I hope your damage isn't to bad Player. It always sucks to bin it but the track is the place if anywhere.

Thanks to Scott and the rest of the team for another great trackday.

Eldon and Neil, thanks for the company and advice out on the track, fun times!

Peace Bash

[cromer611]

If you watch the video and notice how you counter steered into the slide, this tells me that your rear broke first. And yes the front did compress which would lighten the rear. if you would have tucked the front, the tire would have turned full lock to the left.

The rear breaking loose coming into that turn is common, I remember lubing my chain once, and came into turn 2 with lube on my left side of my tire. Before I even got on the gas, the rear was stepping out. I straightened up the bike and got on the gas and rode it out. Remind you I wasnt going very fast.

Remember it is slightly cambered off/on, which ever camber that turns in with you : P So it doesnt take much for the rear to compress in turn 2, even if your not on the gas.

hope this helps

[rybo]

I went with 28/22 on the advice of Rybo

but I told you 30f 22r?

in this case even that was working in your advantage as you would have gotten some additional carcass flex on the brakes, giving you a little more heat in the tires.

[spdr8cr02]

anymore pics yet?

[eg bter]

Good question...where the pics at?

[longrider]

Sorry guys, I was unable to come out that day. Dont worry, I have not quit I will be out to as many track days as I can

[eg bter]

Here are some more from my camera

[eg bter]

[spdr8cr02]

So who was taking pics at turns 3 and 4?

[rforsythe]

That would have been Marc (Vast Action).

[Sean]

That would have been Marc (Vast Action).

http://onthemarcphotography.com/

[eg bter]

He hasn't posted any as far as I can tell.

[rforsythe]

I think he had something around 7k pics to go through. It may take some time.

[rybo]

Marc's pic count was 7162....

damn.

[ryan]

Scotts a pimp, thanks for having us!

[Matrix]

One of the best picture setups I have seen is at Hallett where they have a two man operation going. One guy takes the pics and the other swaps out memory cards and moves the pics into each riders file after each series of sessions continuslly. As a rider I could come in through out the day and see the pics I had on one of three monitors and buy individual or an entire disk.
I am not trying to question anyones business practice or anything like that just want to highlight that people, especially guys, are impulse shoppers. After more then a week I am not sure the impulse is still there.
I want the guys that take pics, run trackdays, and generally do anything around motorcycles to succeed because that means a better product for me...just food for thought.

[badkarma]

That's the way they used to do it at Willow Springs, it works really well

[motolitho]

yeah man, where's my pics? Ok, I'm slow and fat on a stock gixxer- but hey- It's important to me! I wanna see 'em!

[racedk6]

Patience people... they will be up soon.

Remember the thing with Marc is he doesnt just get one or 2 pics of you in one corner. He gets pages of pics of you in alot of different corners.

Also if you didnt fill out the paper he was passing out to describe your bike it makes it harder for him to sort the images.