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Old 02-25-2019, 09:59 PM   #1
jacob11379
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low side

I dont know if there is enough information here to be of value with camera pointing behind.

Video is a bit boring as I left 1st and ran many laps with no one ever coming into view of camera.

Anyway, Im on a 400. its last Saturday at Sonoma. I had been running close to the same speeds for a few sessions. This session however was the last session of the day and the temp seemed to have dropped a few degrees over the previous sessions.

Bike just washed out with no warning. initially I thought I must have added throttle but video doesnt really tell that story.

Crash is at 13:35

https://www.youtube.com/watch?v=riR3TMZmBOQ&t=1035s

I pass through turn 9a and B at

4:46
7:00
9:15
11:25
13:35 crash

My times are pretty consistent, my lines on that turn seem consistent....to me anyway. I certainly feel like I had more lean angle in other turns...

Honestly this corner and low side took me by complete surprise
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Old 02-26-2019, 09:09 AM   #2
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My money is on front tire unloading due to throttle.

You were on the throttle from just past the point you tipped into the first kink, all the way through the second kink. Just before the lowside you opened the throttle more, presumably before taking away lean angle. In doing so you took all the weight off the front tire making it wash out.

Add to that the cloud cover that came in late in the day reducing track temps and grip, and a little bike where you aren't braking much and not generating heat in the front tire.

Last edited by Kalvin00; 02-26-2019 at 09:11 AM..
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Old 02-26-2019, 10:34 AM   #3
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think about when the last time the left edge of the front tire had any real heat put into it... the carousel / T6. then u had 2 straights to really cool it off. that, plus the cold final session is bad news bears. if u were on a bigger bike, the esses and harder braking would help w/ heat on the left.

it also looks like u are going a touch faster and on a slightly different line for the crash. I think u started your flip late.
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Old 02-26-2019, 04:42 PM   #4
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Originally Posted by Kalvin00 View Post
My money is on front tire unloading due to throttle.

You were on the throttle from just past the point you tipped into the first kink, all the way through the second kink. Just before the lowside you opened the throttle more, presumably before taking away lean angle. In doing so you took all the weight off the front tire making it wash out.

Add to that the cloud cover that came in late in the day reducing track temps and grip, and a little bike where you aren't braking much and not generating heat in the front tire.
this is pretty likely as there was a rider about 3' in front of me and I was planning to get around him at T10. He was on a liter bike and i had been tracking him down for some time.
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Old 02-26-2019, 04:46 PM   #5
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Spoken as someone who hidden SP for thirty years, in the early season, on a cold cloudy day, I never push the early AM sessions, or the late PM sessions. That's when most of the crashes happen, just like Laguna Seca. Things that you have done all day suddenly don't work.

I understand there were many crashes both days due to cold track and riders letting themselves get boxed in. Meaning leaving fewer and fewer options as conditions changed and traction went away.
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Old 05-16-2019, 01:36 PM   #6
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Spoken as someone who doesn't know what the fuck they are talking about, to me it looks like you got on the gas during inopportune moment while suspension was trying to rebound combined with cooling tarmac and it looks like a later session. looks like the rear came out based on the rear end spinning around after the slide. Usually if its front i see the bike slide more in a straight line.

like i said idk I'm an idiot, i wouldn't listen to me.
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Old 05-16-2019, 02:22 PM   #7
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it looks like you're adjusting your line a lot through the turn. the bike tips in, then lean angle reduces slightly, then increases, reduces, then throttle.

I would guess this is caused by your vision (and potentially not having consistent markers for brake, turn in, apex, exit - or not consistently using them). Based on the bike's movement it seems like your eyes are jumping around a lot - glancing at an apex marker when you turn in, then looking through the turn, then back at the apex to adjust the line (first apex marker you used may have put you off your line, or your turn in point was off) then back at the exit, etc. One of these micro-adjustments with all the factors mentioned previously I believe caused the wash out.

Or I may just be misinterpreting the video! but my .02
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Old 05-16-2019, 11:06 PM   #8
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Originally Posted by R3DS!X View Post
Spoken as someone who doesn't know what the fuck they are talking about, to me it looks like you got on the gas during inopportune moment while suspension was trying to rebound combined with cooling tarmac and it looks like a later session. looks like the rear came out based on the rear end spinning around after the slide. Usually if its front i see the bike slide more in a straight line.

like i said idk I'm an idiot, i wouldn't listen to me.
probably wouldnt have posted here if i did know dont ya think?

If you want to be disrespectful please do it to my face not on a forum....Thanks
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Old 05-16-2019, 11:10 PM   #9
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Originally Posted by viva_brasil View Post
it looks like you're adjusting your line a lot through the turn. the bike tips in, then lean angle reduces slightly, then increases, reduces, then throttle.

I would guess this is caused by your vision (and potentially not having consistent markers for brake, turn in, apex, exit - or not consistently using them). Based on the bike's movement it seems like your eyes are jumping around a lot - glancing at an apex marker when you turn in, then looking through the turn, then back at the apex to adjust the line (first apex marker you used may have put you off your line, or your turn in point was off) then back at the exit, etc. One of these micro-adjustments with all the factors mentioned previously I believe caused the wash out.

Or I may just be misinterpreting the video! but my .02
all is plausible. after taking CSS I realized a whole lot of stuff I was doing wrong. Not to say i know what im doing now but the vision and markers part you mention was a very big deal. Just after picking up that info I shed 8 seconds off my lap time the next time i rode.
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Old 05-17-2019, 05:40 AM   #10
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probably wouldnt have posted here if i did know dont ya think?

If you want to be disrespectful please do it to my face not on a forum....Thanks
I don't think he was disrespecting you. I read it as he is making fun of himself.

Mad
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Old 05-17-2019, 06:33 AM   #11
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Originally Posted by R3DS!X View Post
Spoken as someone who doesn't know what the fuck they are talking about, to me it looks like you got on the gas during inopportune moment while suspension was trying to rebound combined with cooling tarmac and it looks like a later session. looks like the rear came out based on the rear end spinning around after the slide. Usually if its front i see the bike slide more in a straight line.

like i said idk I'm an idiot, i wouldn't listen to me.
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I don't think he was disrespecting you. I read it as he is making fun of himself.

Mad
Oh I see that now...Sorry redsix, Thanks mad
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Old 05-17-2019, 09:17 AM   #12
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I don't think he was disrespecting you. I read it as he is making fun of himself.

Mad
Correct answer
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Old 05-17-2019, 05:19 PM   #13
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Sorry man....in my haste I took the first sentence entirely different than it actually said.

Appreciate the feedback on the wreck
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Old 05-18-2019, 01:53 AM   #14
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Pretty common crash there when it's cold. There's a seam there and the pavement is two different friction levels...not enough for it to matter on a hot day with hot tires, but on cold days, it takes people down. Slow the video down, you'll see it. Faster guys don't run over it with lean angle in the cold...that seams sucks.

One more thing to note: your entries are coasting and thus, you're losing heat in your front tire. You don't need to trail brake, but you'll need some brake to keep heat in the tire...although I'm not sure if that was contributory.

Seems, it's the seam.
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Old 05-20-2019, 01:13 PM   #15
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Sorry man....in my haste I took the first sentence entirely different than it actually said.

Appreciate the feedback on the wreck
no worries bro
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