Crashes At Phillip Island

[Stroker]

Can some one try and explain why there were so many riders crashing while braking straight up at the Phillip Island GP?

 

[rchase]

A friend of mine was talking about this to me. Found an article that might answer your question. Quick answer? Tires. Front ones.

 

http://www.foxsports.com/motor/story/motogp-tires-may-be-to-blame-for-crashes-in-friday-practice-101714

[FieryRobot]

https://twitter.com/calcrutchlow/status/523863917420752896

[PittsDriver]

Cal Crutchlow was quoted as saying that his crash was caused by coming off the pace on the last lap with the intent of being conservative. He thinks that cooled his tires enough that he didn't have the grip he thought he'd have.

[FieryRobot]

Indeed, just found this:

 

 

 

Crutchlow admitted, “I’m absolutely gutted with today’s result. We didn’t deserve that. The first time I slowed throughout the whole race was on the last lap and the front tyre obviously cooled down. I chose the asymmetrical and this was always the risk that we took. It was just a shame that the only mistake I made was slowing down a bit and not carrying on pushing for the rest of the lap. It’s a disappointment to my team, because I believe they deserved it and I’m really sorry for that."

[Kevin Kane]

If I saw it correctly, wasn't his rear tire off the ground when he washed the front? I guess that's slowing down for some...

Certainly he knows what he's doing and I have no basis to comment beyond what I [thought I] saw. It seemed like he put a lot of load on that front and it just said "no mas!" and let him go.

[faffi]

When informed that Bridgestone maintains the position that tyre behaviour is determined by each individual bike's set-up, Lorenzo simply smiled and responded:

“As always…”

 

http://www.crash.net/motogp/news/209964/1/frustrated-lorenzo-rallies-against-disaster-tyres.html

[Stroker]

So even the GP tires being run at a GP pace in the dry cooled down enough to cause a crash? How much would normal rubber cool off at say the end of a straight? Enough to warrant a change in riding?

 

If so, what changes?

 

A good observation Kevin.I thought Crutchlow and Pol Espargaro braked a little hard, got the rear wheel in the air [ very slightly ] and tried to turn while on the brakes resulting in the front tucking in.Confirmed by a slo mo replay of Pol's crash.

[rchase]

Despite the differences between machinery grip works the same way. You can lean so much and brake so much. They went past those limits and crashed. The solution would be to use less lean angle or brake less aggressively. That's easier said than done in a race situation of course.

[faffi]

If you look at the crashes, they were more what you expect to see in the wet, the front going without warning and impossible to save even for the best riders in the world.

 

 

 

Using the asymmetric soft - rather than the extra soft - front tyre, Crutchlow fell in rapidly cooling conditions that saw the air temperature drop by nine degrees during the race.

Crutchlow felt that even if he had cruised to the end the result would have been the same, such was the knife-edge of running the harder asymmetric compound rubber, citing the example of Pol Espargaro's almost identical accident a few laps earlier.

"I had to keep pushing and I felt fine, I didn't do anything differently, but I had to keep pushing because if I didn't I would have crashed anyway," said Crutchlow. "The lap before Pol Espargaro crashed and almost all the riders that used the '35' [asymmetric] tyre all crashed.

I made a mistake and didn't finish the race, it's as simple as that, but I don't believe that it was my mistake."

It was a very easy race for me, I just looked at my pitboard and was making sure to finish the race, but we had some problems with the front tyre over the weekend. I saw Marc crash, I saw Pol had crashed and then I crashed.

"We all were using the hard [asymmetric] front tyre and we've seen how many people have crashed this weekend. The temperature dropped nine degrees during the race and I never made it to the finish. I'm disappointed to crash on the last lap, it looks like I made a silly mistake but I had to keep pushing because I had no heat in the front tyre and if I didn't push I would have crashed anyway."

It was an incident-packed race for Crutchlow as he came back through the pack from a first corner incident with Andrea Iannone before battling through to run the majority of the race in fourth position:

While the decision to run the asymmetric tyre in the race left Crutchlow susceptible to losing temperature in cooling conditions the alternative of running the extra soft tyre, as used by Jorge Lorenzo, left him feeling that he wouldn't have been able to maintain tyre life throughout the race.

"I was happy with my pace and I really believed that one of the riders in front of me would come back to me because I thought that they'd have the front tyre problem with the 31 [extra soft], this was the reason that I didn't use the 31 in the race.

"In the test I did 17 laps with it and I destroyed the tyre, the same as Lorenzo and Valentino, and today Lorenzo came backwards like a stone because of this. That was why I choose the 35 [asymmetric], it was just to finish the race.

"I really didn't know what happened to me, at one point I thought that someone had set off a bomb and I'd been blown off the bike but you can look at how many riders crashed this weekend at the same point." "The first time I slowed throughout the whole race was on the last lap and the front tyre obviously cooled down. I chose the asymmetrical and this was always the risk that we took. It was just a shame that the only mistake I made was slowing down a bit and not carrying on pushing for the rest of the lap."

Marc Marquez: "Today, because I had no pressure on me, I tried a different approach pushing hard from the start to try to open the largest gap possible. We were having a good race, right up until the crash. It was a pity that I went down at a time that I was not riding on the limit or faster than the lap before. It was a race where there were many crashes, and almost all happened the same way: the front wheel locking up. The temperatures were down a lot, something that was also a factor today."

Pol Espargaro:

I lost the front at turn four, without any warning which is what also occurred for Marc and Cal. The track temperature had dropped slightly and obviously racing at 16:00 in the afternoon in not an ideal time to keep the heat in the front tyres and that's exactly what happened. We probably wouldn’t have been able to race the soft tyre, so we had to adapt to the harder compound which caused the unfortunate end result for me in the race.

[Stroker]

Good point, but for some reason it seemed like someone kicked the front away from them....just a sudden crash.

 

I wonder if we should have a " Crash Stories " thread...where we can discuss crashes we have had.

[faffi]

As a layman without any knowledge worth mentioning about this tyre theme, I do wonder if a "normal" rider would notice such a drop in tyre grip? Would, for instance, a CSS instructor find the grip drop below that of his or her usual tyre just because the temps dropped 10C and the pace dropped a second per lap, making him or her crash unexpectedly as well? Or are these riders pushing the outer limits constantly to a level that even a minute change in grip will be considered "massive"? Inquiring mind wants to know

[Hotfoot]

Tires cooling off and having less grip is common while coaching. Generally the coaches are using race tires, which are designed to work best when thoroughly warmed up. The tires can cool off rapidly if we stop to watch and wait for a student, especially on a cool or windy day, and for sure we have to be conscious of that when we take off again. I always pay close attention to the traction and ride conservatively for at least 2-3 turns to feel it out before picking up the pace.

It also happens sometimes that we have students that ride at very different speeds, and anytime there is a transition from a moderate pace to a fast pace we are cautious to make sure the tire is properly warmed up before really pushing the pace.

You asked if it can be perceived, and yes it definitely can. How easily it is felt probably depends somewhat on the specific type of tire, but on the race tires here is what I notice: if they are REALLY cold (first ride out) they are harder to turn in and the bike feels like it wants to stand up in the corners instead of holding its line. If the tires are partially warm but not fully up to temp they will feel a little squirmy in the turns or do little tiny slides on the front tire; generally I just start increasing lean angle in the turns bit by bit until they warm up and start feeling planted. The Q2 and Q3 tires, though, seem to have a lot of grip at a much lower operating temp so I rarely notice any difference in feel in those, except in the very first laps in the morning or after the bike sits a long time.

There are a lot of tips and tricks on managing cold tires, some of the CSS techniques are very useful - anybody care to name some of them?

[Stroker]

I am waiting for the answers.

[Hotfoot]

BTW I rode at Las Vegas Motor Speedway on the S1000r all weekend on the Q3s. The tires are really impressive, I really like how they handle and the grip is amazing.

[faffi]

Hotfoot, even I could easily tell when the Bridgestone BT001 was cold, and on a cold day it was very slippery. But, probably poorly worded, what I wondered if you think a tyre could cool down enough to be easily felt by you after slowing down your pace from a 92 second to a 93 second lap mid-race? Because that's what the racers claimed, that slowing a second per lap made the tyre cool enough to be next to impossible to read. To me, that indicates that either the tyres are sh!te or the riders are pushing so far beyond what we can comprehend it ain't even funny.

[Cobie Fair]

Blow dryer?

[Hotfoot]

Hotfoot, even I could easily tell when the Bridgestone BT001 was cold, and on a cold day it was very slippery. But, probably poorly worded, what I wondered if you think a tyre could cool down enough to be easily felt by you after slowing down your pace from a 92 second to a 93 second lap mid-race? Because that's what the racers claimed, that slowing a second per lap made the tyre cool enough to be next to impossible to read. To me, that indicates that either the tyres are sh!te or the riders are pushing so far beyond what we can comprehend it ain't even funny.

 

Well, I don't know what their tires are like at that level but it does seem possible to me that a 10C temp drop and slowing down 1 second per lap could make enough difference in the grip to surprise a rider, and that presumably they ride enough on the edge that there is no room for recovery when taken by surprise. It also seems possible that they could not (or did not) perceive the change in grip and that resulting in a crash. If they were not aware of the change in air temp (which seems possible in a race setting) they might not have factored that in - possibly just slowing down a little would have been OK without the temp drop, but both together was too much.

 

I also think riding on an asymmetrical tire would make judging the level of grip more difficult, especially if different parts of the tire are cooling unevenly as the temperature changes.

 

Of course it is also possible that there is something about the tire they really don't like but they are trying not to say anything negative.

 

I will say that I was shocked, when I started riding on race tires, at how quickly they could cool off (especially if they are getting worn) and start to feel slippery compared to a mid-range or street tire; on a cold day you can sometimes never get the tire warmed up at all, or you can have it cool down in the middle of a lap on one side if you have a section of the track with no left turns, for example, so the rights feel OK but the first left turn gets sketchy.

[PittsDriver]

I've never been on slicks at the track, always a soft compound street tire. Something I've always been really curious about is the level of grip when you contrast, say the Dunlop Q3 vs. the slicks the coaches run at CSS. What kind of pace must you keep up to keep the slicks performing better than the Q3? What criteria would I use to decide that it's time to think about slicks and tire warmers for a track day vs. running the Q3s I have on my S1000RR.

 

I ran my Q3s at 29 rear, 31 front and the looked like they were getting plenty of heat in them:

 

 

There were times that I felt like the traction control was overriding the throttle when leaned over and it makes me wonder what that would feel like on slicks.

 

Wes

[Spaghetti]

At 1:32 in the video you can see Marquez front tire smoking right before the loss of grip and crash (go to 1:31, change the replay speed to 0.25, then quickly double click on the play button to advance one still image at the time). That looks more like a blocked front wheel than a tire problem. Bradl crashed into another bike. Crutchlow, at 1:25 in the still images you can see the rear tire almost lifting off the track, plus that odd leg position with the body upright while turing into the right corner (this guy should register at CSS and get his body position checked ).

 

I think this was too much asking to the asymmetric tire on an extremely fast track, reason why some riders decided to go for the soft and slow down through the race. Those crashes don't look like bikes going at a slower pace to me.

[Stroker]

Wes - I think that is a picture of a rear tire? You might want to get your suspension set up checked.The tire is suffering a bit when you are leaned over and gassing it, hence the feeling of a loss of traction.

[PittsDriver]

Wes - I think that is a picture of a rear tire? You might want to get your suspension set up checked.The tire is suffering a bit when you are leaned over and gassing it, hence the feeling of a loss of traction.

 

I think an S1000RR will make any tire suffer a bit Both tires wore evenly with no tearing or scalloping but I'm open to all observations.

[Hotfoot]

I've never been on slicks at the track, always a soft compound street tire. Something I've always been really curious about is the level of grip when you contrast, say the Dunlop Q3 vs. the slicks the coaches run at CSS. What kind of pace must you keep up to keep the slicks performing better than the Q3? What criteria would I use to decide that it's time to think about slicks and tire warmers for a track day vs. running the Q3s I have on my S1000RR.

 

I ran my Q3s at 29 rear, 31 front and the looked like they were getting plenty of heat in them:

 

 

There were times that I felt like the traction control was overriding the throttle when leaned over and it makes me wonder what that would feel like on slicks.

 

Wes

 

I think this question should be moved to the tire forum to have Steve the Dunlop guy answer.

 

It is pretty amazing how hard you can run those Q3s. What mode are you using on the S1000?

[PittsDriver]

 

 

I think this question should be moved to the tire forum to have Steve the Dunlop guy answer.

 

It is pretty amazing how hard you can run those Q3s. What mode are you using on the S1000?

 

 

 

I ran in "race" mode for the track day where this photo was taken. Some video of a few laps is in another thread on here for some perspective on how hard the tire was treated. It makes me wish I'd had a data logger on the bike so that I could see if the DTC was intervening on the drive out of the corners.

[YellowDuck]

I've never been on slicks at the track, always a soft compound street tire. Something I've always been really curious about is the level of grip when you contrast, say the Dunlop Q3 vs. the slicks the coaches run at CSS. What kind of pace must you keep up to keep the slicks performing better than the Q3? What criteria would I use to decide that it's time to think about slicks and tire warmers for a track day vs. running the Q3s I have on my S1000RR.

 

 

 

I am not saying that the information I have to offer here is scientific, but I do have some experience with this comparison. I am just a first-year racer with about 5 years track experience. I am fast enough to be competitive in the less-hotly-contested novice classes, but nowhere near expert racer level, nor even a podium contender in a very competitive novice class like 600 supersport. So, red group at a track day, but not amongst the very fastest in that group. Get the picture?

 

At that skill level I can out ride Q3s. We run the Dunlops on our endurance bike (an 11-year-old Suzuki 600), and they do get a bit overheated if I ride that bike at my sprint-race pace 5 or 6 laps. They get slightly greasy under hard braking and have less corner grip as well - it is easily noticeable by someone at my skill level.

 

Compare that to my sprint race tires (Bridgestone V01-R slicks). At race pace I am able to keep enough heat in those tires that they work properly, but I simply can't out ride them to the point that they overheat and get greasy. I can (and do) still crash, but if I do it is not because I overheated the tires.

 

I say this is not "scientific" because it is not as if I have tried every possible pressure setup to try to regulate temperatures. Maybe the Q3s could be kept cooler. But my general impressions seem to be in line with what you would expect, comparing race tires to upper level street tires. I think the difference is real.

 

When I was an upper-intermediate group track day rider, I was never over-riding the Dunlops (Q2s at the time) until they were worn out. Even at my current faster pace, if I was only doing track days for fun I would probably just run Q3s and accept the minor limitation to all-out pace - they are way more practical than slicks. But if I was going to the track day to try to beat my personal best laptime, I would use the slicks and warmers.

 

Hope that helps. YMMV.

 

Edit: Here's a thread I started last winter on a similar subject: http://forums.superbikeschool.com/index.php?showtopic=4045