Barber Lowside with Mary!
- Thread starter Lenny ZX9R
- Start date
I got a few minutes to kill at work so might as well shed some light on a common situation the CR's find themselves in.
If you watch Lenny's video in its entirety, you'll get a feel for the pace he was running - how hard he was braking and accelerating in general. And if you notice, on the crash, he gave it quite a bit more throttle going into Turn 1 than the previous laps (to get around those riders) - which in turn required more brakes (YCRS...More speed = more brakes). The problem is that the tire wasn't up to optimal temperature, because the previous laps did not generate enough heat in the tire to maintain the new pace he was running. He did not ask too much from the tire - those Dunlop's go wicked fast when ridden by MotoAmerica riders, he just asked too much too soon, from a luke-warm tire. It's a far too common situation for CR's to find themselves in, and will quickly bite you in the ass if you aren't paying attention. You have to be really careful if you ride with someone that's in the slower part of a group for a few laps, then try to work with a rider with a pace that's fast enough to be bumped up to the next group. Same thing can happen.
There's a lot of factors that play into it. And honestly, if this was in the middle of summer, chances are he never would have tucked the front, regardless of tire brand. But this is one of those cases that "the speed is up and the grip is down". Grip was down, from the over all colder track day, and luke warm tire. The crappy thing is that there is zero warning signs with a cold tire crash, it's like opening a door and getting sucker punched.
If you watch Lenny's video in its entirety, you'll get a feel for the pace he was running - how hard he was braking and accelerating in general. And if you notice, on the crash, he gave it quite a bit more throttle going into Turn 1 than the previous laps (to get around those riders) - which in turn required more brakes (YCRS...More speed = more brakes). The problem is that the tire wasn't up to optimal temperature, because the previous laps did not generate enough heat in the tire to maintain the new pace he was running. He did not ask too much from the tire - those Dunlop's go wicked fast when ridden by MotoAmerica riders, he just asked too much too soon, from a luke-warm tire. It's a far too common situation for CR's to find themselves in, and will quickly bite you in the ass if you aren't paying attention. You have to be really careful if you ride with someone that's in the slower part of a group for a few laps, then try to work with a rider with a pace that's fast enough to be bumped up to the next group. Same thing can happen.
There's a lot of factors that play into it. And honestly, if this was in the middle of summer, chances are he never would have tucked the front, regardless of tire brand. But this is one of those cases that "the speed is up and the grip is down". Grip was down, from the over all colder track day, and luke warm tire. The crappy thing is that there is zero warning signs with a cold tire crash, it's like opening a door and getting sucker punched.
Lenny ZX9R
Control Rider
I wold say that Barber has good grip in the cold but the sun has to warm the frack a little! When I went down we did a few slower laps and the sun was not out, it was overcast so no heat for the track! The tires SHOULD have had some heat in them, but as you know when you have a few slower laps and no sun, the track sucks the heat out of the tires! I had taken that line many times at a faster pace earlier in the day with no problems but, I got bit by a cold front tire1 I rode the bike back to the pits and felt it and it was just warm
Lenny ZX9R
Control Rider
100% agree Vin!
Lenny ZX9R
Control Rider
Thanks AJ! Could Jen Make some Chocolate Chip cookies with that? LOL!
Lenny ZX9R
Control Rider
[/QUOTE]If you watch Lenny's video in its entirety, you'll get a feel for the pace he was running - how hard he was braking and accelerating in general. And if you notice, on the crash, he gave it quite a bit more throttle going into Turn 1 than the previous laps (to get around those riders) - which in turn required more brakes (YCRS...More speed = more brakes). The problem is that the tire wasn't up to optimal temperature, because the previous laps did not generate enough heat in the tire to maintain the new pace he was running. He did not ask too much from the tire - those Dunlop's go wicked fast when ridden by MotoAmerica riders, he just asked too much too soon, from a luke-warm tire. It's a far too common situation for CR's to find themselves in, and will quickly bite you in the ass if you aren't paying attention. You have to be really careful if you ride with someone that's in the slower part of a group for a few laps, then try to work with a rider with a pace that's fast enough to be bumped up to the next group. Same thing can happen.
There's a lot of factors that play into it. And honestly, if this was in the middle of summer, chances are he never would have tucked the front, regardless of tire brand. But this is one of those cases that "the speed is up and the grip is down". Grip was down, from the over all colder track day, and luke warm tire. The crappy thing is that there is zero warning signs with a cold tire crash, it's like opening a door and getting sucker punched.[/QUOTE]
100% agree John! I should have been paying attention to the colder temps and maybe gone around another lap before picking up the pace!
Great observation John!
There's a lot of factors that play into it. And honestly, if this was in the middle of summer, chances are he never would have tucked the front, regardless of tire brand. But this is one of those cases that "the speed is up and the grip is down". Grip was down, from the over all colder track day, and luke warm tire. The crappy thing is that there is zero warning signs with a cold tire crash, it's like opening a door and getting sucker punched.[/QUOTE]
100% agree John! I should have been paying attention to the colder temps and maybe gone around another lap before picking up the pace!
Great observation John!
physicistkev
Control Rider
Sorry to hear about the crash Lenny. A lot of people had low sides this weekend.
I got Kas's lowside in 5. He was right behind me. I was right behind Chris, the video above, but my cameras weren't on.
In general, the track was great for traction. You needed to give it an extra lap or 2 to make sure heat was in the tires. I am surprised to hear about the Dunlops being poor in the cold. I had no issues with my US spec slicks all weekend. I also didn't go crazy on the first lap though. I gave it 2 or 3 laps and even then if they weren't up to temp they let me know without to much drama.
We had a lot of front end low sides over the weekend. Turn five and fourteen claimed a lot bike parts this weekend. It was mainly due to not getting heat into tires.
I will post my vids up shortly.
I got Kas's lowside in 5. He was right behind me. I was right behind Chris, the video above, but my cameras weren't on.
In general, the track was great for traction. You needed to give it an extra lap or 2 to make sure heat was in the tires. I am surprised to hear about the Dunlops being poor in the cold. I had no issues with my US spec slicks all weekend. I also didn't go crazy on the first lap though. I gave it 2 or 3 laps and even then if they weren't up to temp they let me know without to much drama.
We had a lot of front end low sides over the weekend. Turn five and fourteen claimed a lot bike parts this weekend. It was mainly due to not getting heat into tires.
I will post my vids up shortly.
mdhokie
Member
Menotomy, watched through that video a few times...it sounded like you were picking up the throttle right before it slipped, before reducing lean angle; was it the rear tire that went out? You could see the turn exit so I can see why you'd accelerate there but maybe just a little too much for the lean angle? Or is my analysis all wrong? It's hard to tell in real time what's going on. Everything is fine and then you're sliding.
The cold tires thing scares me; does anybody know the actual temperatures for the day? I learned my own lesson on cold tires several years ago by high-siding at about 30mph like Otto Man except on the street, pulling onto the highway out of my neighborhood when it was 29 deg F. Spun up the rear tire, got off balance and my weight ended up on my throttle hand; left 30-foot trail of broken plastic bits and quite a repair bill. But I really don't have a feel for the tradeoff in temperature/traction at middling temperature between 50-70 degrees. Is traction off by a few percent at 50 degrees, say, or is half the traction gone? Anybody seen any pretty temp/friction coefficient charts that explain how much the grip falls off as it gets colder for various tires?
The cold tires thing scares me; does anybody know the actual temperatures for the day? I learned my own lesson on cold tires several years ago by high-siding at about 30mph like Otto Man except on the street, pulling onto the highway out of my neighborhood when it was 29 deg F. Spun up the rear tire, got off balance and my weight ended up on my throttle hand; left 30-foot trail of broken plastic bits and quite a repair bill. But I really don't have a feel for the tradeoff in temperature/traction at middling temperature between 50-70 degrees. Is traction off by a few percent at 50 degrees, say, or is half the traction gone? Anybody seen any pretty temp/friction coefficient charts that explain how much the grip falls off as it gets colder for various tires?
That's a question that comes up a lot at YCRS when they talk about the 100 points of grip for a tire. Unfortunately, it's literally impossible to chart it, because there are so many variables it'd never happen. The 100 points of grip is a sliding scale. In Lenny's case, his luke warm tire has a 100 points of grip. And that same exact tire, on the same turn, in the middle of July on a sunny day while he's out there riding in A group, will still have 100 points of grip. But it will be operating at temperatures it was designed for, so it's 100 points of grip will be at a higher threshold than this past weekend.
Kevin, the CR who was following me, said that I made an adjustment at full lean and that caused my front tire to go out. The front tire definitely tucked, I felt the handlebars give out. After watching the vid I was wondering the same thing though, it looks like I opened the throttle before picking up the bike, which would mean even though I didn't lose the rear it took enough weight off the front that contributed to me losing traction in the front. Someone else thought maybe I didn't load the front enough. But you're right, everything was fine then I'm sliding!
Mike:p
Don’t be a Hero, be consistent.
I thought the sliding scale started at 100.00000000001
mdhokie
Member
I both do and don't like the 100 points of grip paradigm. It's important to illustrate the trade off between lean angle and braking/acceleration is always the same. I get it. It's absolutely not helpful in telling you how to know when you've reached the full 100 points other than "because then you crash." Crashing is a painful and expensive teacher, so how does one acquire the "feel" for when you're on the edge of traction? Supposedly the tires make noise to tell you, but over the engine and wind, I certainly couldn't hear anything in time to adjust from the video.
As I read through this I began to visualize my 1st low side crash (turn 1 at VIR). I now understand exactly what happened. Made a pass on the brakes and tucked the front after only my 2nd lap shuffling around on a cool day with cool tires.
Thanks John
Thanks John
I'm just glad Lenny's ok cause I know he likes to share and I LOVE chocolate chip cookies!
From someone who has had both a hot and cold tire lowside (sorry Kevin, never be able to say it enough), you can feel the hot tire gripping and the suspension working right up to the point of failure. The cold tire just gives out , no grip with little to no suspension and with a huge surprise!
tdelegram
Control Rider
That's the feel part, you have to crash to know where the limit is and the limit is variable meaning all of the inputs that go into the bike change the limit (tire age/wear, temperature, body position, lean angle, throttle/brake application, track temperature, track grip, on line/off line, how many chocolate chip cookies you have eaten). The alternative is to slowly push the pace until the tires/suspension are maxed out. Loosely quoting a line from Hitting the Apex "you have to push the limit to know where its at." In al reality, get a dirt bike either a small 100 (can double duty as a pit bike) and start riding in the mud, you quickly find the limit and get comfortable sliding at much lower speed and with less expensive and painful out comes when you have exceeded the limit.
You acquire the "feel" over time, experience, and going past the edge. Explaining the "edge" is impossible, as only those that have gone past it know where it's at. When I first started, I struggled at learning how to read the bike. I would crash and not really know why it happened. But after going through some real riding schools, I learned I was man handling the bike. Muscling the bars. The bike absolutely talks to you before a crash (excluding cold tire crashes...), you just need to learn how to listen.
I did love a line from the movie "Hitting the Apex", where they say "You can get a fast rider to stop crashing, but a slow rider will never be fast".
Does this mean you have to crash your brains out every track day to get better? Absolutely not. But by applying the fundamentals that YCRS teaches you, you absolutely can learn to maximize the grip from your tires, and minimize the chance of crashing.
If you really want to learn the edge, get into dirt bikes. I just picked one up myself and am having a blast. I lay my bike down (not really crashing...most of the time) probably at least twice every time I go out. It's a hoot, and it's far less painful and costly to low side a dirt bike in the mud than our street bikes.