r/Trackdays • u/manuel-cadence • 16h ago
Can you tell me why I crashed?
I was at Sonoma in intermediate group for a track day riding my ninja 300. During session 3 of the day, I sadly crashed at turn 9 (bus stop).
I've attached a clip that mashes up videos from my rear-mounted insta360, my in-helmet cam, and a rider following me respectively.
This crash has stumped me so far. This session, I was actually focused on my exit drive at turn 11. At turn 9, I'd say I was spending at most 70%-80% of my max effort. I was not pushing at all. In fact, since an earlier crash in Laguna Seca (grabbed brakes hard) and subsequent discussions with some ChampSchool peeps, I now prefer long, light braking to the heavier, shorter style. At this turn in this session, I was not at all fazed by my entry speed nor was I panicking. Not a walk in the park, don't get me wrong.
I felt my front tire go over something rough and slip out. Soon enough, I was sliding on the asphalt :(
On the same day as the crash and at the same event, I showed the videos to multiple trackday instructors separately and independently, there's been no consensus on why this happened. I've heard cold tires (fell on my left and had mostly been through right turns?), bad line, slippery curb, etc. I'm trying to look within but I can't pinpoint what I did wrong (I'm guessing I'm not at that level yet?). I have my personal suspicions but I'm not very certain and if this is a vague case, I'm worried to sort of bias folks towards a certain theory.
I'm now presenting my case here hoping experienced folks could guide me to what I need to work on. Please, let me know what you think and feel free to ask any clarifying questions. I do have brake/throttle data set up for logging on my bike and I did press record before the session but after the crash, none of that information could be recovered :(
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u/OHBHpwr 15h ago
Could be the curb but my vote goes for adding throttle and lean angle at the same time when hitting that curb.
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u/BellFront3609 6h ago
Yeah I heard the revs pick up just as/after the bike squatted. Rear suspension was extending/reacting as power was being applied.
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u/CardiologistSalt4114 Not So Fast 15h ago
You see… your skill level is slight below where you crashed… in all seriousness I’m guessing those rumbles on the curb had no traction at all. I saw bounce bounce slide. I know super duper advanced terminology
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u/kinnikinnick321 14h ago
To me the 1:23 describes it all, you hit the curb at a lean angle that made the bike unsettled. Being pitched over, your weight naturally forces the bike to go sideways, you can even see the rear tire lift from your knee puck coming down onto the curb. Odds of trying to save/recover from something like that is pretty much impossible when the curb is met that way.
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u/Zealousideal-Act-429 10h ago
The tires should maintain contact with the track. That’s clearly not the case in that left corner
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u/New_Ad7177 15h ago
You added throttle while adding lean.
You should have waited a bit longer. Also, when you add throttle, pick the bike up. That way you have lean angle at the bike, so it has more grip.
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u/Payamux 6h ago
aren't you supposed to add throttle while you lean to keep the momentum?
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u/New_Ad7177 6h ago
No, you only add throttle when you start to pick up the bike and decrease the lean angle.
You still have momentum from the straight. If you do not have it, you braked to much. Then the corner is already fucked up and you take the loss.
If you then try to add throttle coz you are to slow, you will most likely not get a time at all coz you end up like OP :(1
u/SnooGadgets9669 5h ago
The safest way to add throttle back on is when your done leaning over on a long sweeper you gently roll the throttle in without maneuvering the bars but you can’t accelerate hard until your picking the bike back up again.
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u/xtanol 3h ago edited 3h ago
Depends on how far leaned over you are and how much grip your front tire needs to avoid slipping.
Adding lean and throttle simultaneously doesn't by itself mean that you will lose grip - it's just two factors that both reduce your front tire grip at the same time, which means you'll blow past your grip limit faster with less time to react.
Your available grip is essentially just the friction coefficient between your tire and the track × size of the contact patch × the weight pushing down on that contact patch. Leaning over makes the contact patch smaller while also lowering the vertical force pushing the tire down into the ground, and adding throttle shifts weight from the front to the rear tire.
There's plenty extended soft corners on tracks where adding throttle and lean at the same time is perfectly fine, since you'll still be well within the limits of the front tire.
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u/Snoo_67548 Fast Guy 15h ago
I agree with others about you coming over the bumpy curbing and losing it. I think if you apexed the right, you would get a better angle of attack on the left. A tip on that right to left transition: keep your upper body closer to the tank in the transition. This was a tip shared from a pro racer. It saves you time and energy.
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u/Creech-Chong-1000 14h ago
Missed the first apex by a yard, had to come too hard to the right, then overshot the next one by nearly as much. You could ride a straighter, faster line through there and still not touch the rumble strips on either.
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u/Matt_Moto_93 14h ago
Looks like you grabbed a bit of that inside curb on the left hander exiting the chicane.
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u/NecessaryGuava2004 13h ago
From behind, it looks like you lost the rear instead of front. You went on the curb and lost traction under too much throttle too soon and lean. Maybe dial in rear suspension ? How do you feel about that ? I think this bike doesn't have a traction control or ABS, and if so, was it enabled ?
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u/Pillokun 13h ago
if u dont pull the brake lever in, then it 100% something on the surface of the track. So many times I have seen such crashes and the only explanation I can find for such crashes is that a bike has is dropped a bit of fluids.
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u/Purple-Breakfast-356 12h ago
as i saw at 00.31 the rear tyre starts to hop, as a result your fall.
Thats the most simple explanation....
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u/Affectionate-Gur-807 11h ago
Imo you lost the rear driving out of the corner when you hit the curb. If you hadn't gone over the curb you would've been totally fine.
The curb is above the pavement right, and it's sloping down towards the pavement, so by going up on it, even if you keep the bike at the same angle, your lean increases the same amount the curb is sloping.
Add the paint on the curb to that which probably doesn't give you the same grip and you loose the rear.
The only thing i would take from this is to make sure the line is off the curbs.
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u/Rippleracer Racer EX 11h ago
Looks like you hit the rumble strips and the front folded, they can be pretty savage at some circuits, they look pretty rough. Lifted the weight from the front and it slid out.
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u/triumph6t 7h ago
Sorry for the crash. Good thing you are safe. Are you wearing airbag jacket in this video?
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u/JsTn96 6h ago
You were adding lean angle while adding throttle which caused your front end to wash out. This is 100% what happened you can see it and hear it. Remember to be patient and get direction sorted before you start applying throttle out or through the corner.
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u/HooKerzNbLo 2h ago
He lost the rear. He didn’t push the front. Still same reason though. He applied too much lien and too much throttle at the same time. Loss of traction. Not really a lot more to the crash than that.
I will also say his body position needs a lot of work though. He’s very crossed up.
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u/JsTn96 1h ago
He did lose the front, if he would have spun up the rear we would have seen him get bucked or the bike would have spun with him still on it. The reason we brake into corners is to load the front tire and we keep corner speed to keep the suspension and tire loaded only once you have direction do you apply throttle because once you apply throttle the weight bias and tension on the chassis goes to the rear instead of the front. Because he didn’t have direction and tried to apply throttle and lean at the same time he unloaded the front tire causing the suspension to elongate and finish pushing the front tire out in front of him. Only after he has crashed does the rear tire start to spin and spin the bike because the rear still has contact to the ground meanwhile the front is laying on fork/calipers.
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u/sexwithsoxon 6h ago
Agreed with most comments here - just commenting that when it went, it went super quick. Bummer G
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u/Advanced-Issue2406 Fast Guy 6h ago
You lost grip going over that crack on the curbing with too much lean angle... Last clip clearly shows it @ 1:22...
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u/SnooGadgets9669 5h ago
Yeah idk I’ve ran of the rumbles at a few different tracks and the bike stayed up course those were dry sunny days. I really think it was a combo of adding elan angle and throttle while being in the curb
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u/bma_961 Club racer/TD instructor 5h ago
Was this at R-World?
Basically bad line + slippery curb. I don't know what you're meant to do on a small bike, but on a bigger bike you should have much better direction at that point - finished turning and already getting on the gas for a good squirt before 10.
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u/Unbelivabley_Smol 4h ago
Bike following was in 2nd and managed the turn at your speed (even had time to come to a stop next to you). Looking back at your on board shots your rpm was well up in the corner did you possibly throttle on too early? Also you very much look like you ride IN the bike not ON the bike. I believe it’s ok to get a whole ass cheek off to the inside of the seat in mid corner?
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u/_-DEVGRU-_ 4h ago
Way too much throttle/lean at the same time entering the 2nd curve, a perfect way to lose traction.
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u/PhilipConstantine 3h ago
Half the times I’ve lost my rear it was on paint. Anecdotal sure. Full lean on paint you better have really good tires in proper condition if you are going to add any throttle.
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u/Flokifraheden 2h ago
Too much courage not enough talent.
Other than that, It looks like you hit the curb and upset the suspension.
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u/DailyxDriven 1h ago
I think your bike hit the curb just enough to unload the front. Then add a lean to the left and down ya go
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u/19RockinRiley69 1h ago
I thought I saw you hit something and your tire came up and you flew, not real sure though!!
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u/Turbulent-Suspect-12 Not So Fast 15h ago
Looks like it started stepping out on you before you went down—improperly loaded front—but I couldn't tell you what exactly caused it. My guess from the 1st and 3rd PoV is that it was already a little unsettled going from corner to corner, and when you went over the curbing it was just a little too much too quickly.
I think entering the turn, you probably could've kept the long, light braking and been fine here if you just gave it a little more from the start to keep the front end planted.
Just my interpretation.
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u/JR-Banks 15h ago
Classic lean + added throttle + turn in all at the same time. Exactly how I had my first track crash.
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u/mattblack77 15h ago
He was past the apex tho; I think he just lost the front on the kerb on exit.
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u/JR-Banks 15h ago
Nope. he was on the gas before the Apex while turning in and leaning at the same time.
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u/throwaway222999122 15h ago
This is just amateur opinion as I'm not an expert.
I don't think it's the curb.
For me, the counter steer into the tip in point, you can still be on the brakes, (trail breaking, decreasing pressure on the front brake). But once you're done with the trailbreaking, that is your maximum lean angel, you could maintain it with throttle, hence riders slide knees etc , but you can't increase it, while throttle is applied, as throttle makes, the bike stand up.
Too quick on the throttle on the exit, while still trying to maintain if not increase lean angle, to sharpen your exit.
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u/piglacquer 16h ago
Only ridden one track day, so I'm an armchair expert at best, but it looks like you were fully on the curbs there. I imagine that's enough to lose traction.