So, why did I crash?

[EarlyBird]

Skydriver:

Do you have your bike set up for your weight? What is your SAG! I watched the video, and it seemed like your bike was bouncing hard.. quick sharp force seen in the camera. Do you have a zip tie around your front fork? You could be way to stiff or way to soft. Too stiff the tires is doing all the work! Too soft...bottoming the front fork to the stop.... no suspension... tire doing all the work! I wish the video had your hands in view to see. Deceleration in a turn with no gas to put some weight on the rear, and to balance out the chassis would also cause the front tire grip. But I also have to agree with what you wrote:

1: cold track
2: older tires
3: Coming into a corner with no gas to maintain the bikes drive and balance
4: Suspension settings?

I am doing a open track day at V.I.R. March 29th, and hope to not have the same thing happen, so I am curious from learning from others mishaps too to help prevent my own.

 

[BIG GUY]

Glad to hear that the leathers worked out for you. It does sound like it was the de-accelerating in the turn and the tires being a little worn out.

 

[racerV]

It seems to me you were running in too high of a gear the entire time. That bike should have been screaming and I think that you were using brake instead of deceleration which in turn caused your get off. I have never run on that track however I think Steve can attest to my control on the street. I am going to stick with braking issue....

 

[skydivr]

Here is what my buddy said (he was there, full yellow R1)

Tell your buddy I said thanks for the info. I agree with everything he said.

From Sunday's pics (When I'm on my Busa) I'm not very happy with my body position, either. Oh well, gotta learn somehow!

 

[skydivr]

Warbird, I'm running the same suspension settings Tufbusa runs (he gave them to me and we have the same bike and same approximate weight). Zip tie shows I'm running about 2/3 to 3/4 of the shock. Not touching brake in turn, but was coasting.

I KNOW it's my fault, just trying prevent it in the future. From the pics from Sunday on my Busa I know I need to work on body position.

 

[Tufbusa]

Sorry about your get off Keith. Thank goodness it was an easy get off with light bike damange and you came out unscathed. However, we do get to see you doing the tuck and roll in the back ground

Since this is an opinion thread, I'll throw mine in as well.

Bikes don't crash on their own. Unless a fork leg breaks, it's alway rider decisions and input that ends with a crash.

If it was your second lap on a cold day, your tires, especially the front, was still under 100 degrees. My guess would be more like 70-80 degrees. About half what they should be to reach maximum grip. You were useing the brake very little and only gingerly when you did. Braking is what heats the front tire while accelleration is what heats the rear.

Let me point out LOUD & CLEAR, bikes don't like coasting when leaned over. Throttle control is EVERYTHING when it comes to cornering. Coasting loads the front which only has about half the contact patch size as the rear. Proper throttle relieves the front of 10-20% of the weight and places it on the rear.

Rarely is a crash caused by a single error, it's usually a combination of multiple decisions/errors. From what I can see, second lap cold tires. At least part of the problem occurred from lack of brake use to heat the tires properly. OAT (Outsice Air Temp) was down around 50 degrees, requiring a special effort to create heat in the front tire. OEM street tire that had been on the bike since new (Three Years) was no longer performing at 100%.

Throttle Control could easily have changed the outcome. Adding a little throttle a second or two earlier would most likely have saved the crash all together.

As I have said on may occasions, tires are only one factor in the equasion. However, the better tire you choose the more mistakes you can get away with. Touring tires or old used tires won't tollerate mistakes that a high performance tire will.

If it makes you feel better Keith, we had our very first track day of the season yesterday. Wet and cold in the morning warming up to mid-fifties by mid-afternoon. We had crashes in every morning session and a few in the afternoon. The sneaky crash snake can raise his ugly head at any time and usually when least expected. The very best thing you could do to improve your skills would be to enroll in a school. We all have bad habits and you'll be schooled on what you are doing wrong and how to correct it. A single school day will flatten the learning curve considerably!

 

[bazooki]

+1

I went to a race school two years ago and it was the best money I ever spent! I am kicking myself for not going 20 years earlier though.....

 

[09BusaDrvr]

Keith, great thread, thanks for posting it up here....I always love reading Tufbusa's comments, his analysis always seems to be spot on, at least it was with my crash. Mostly, I like learning from other peoples mistakes in hopes that I do not have to repeat them. I have never really thought of going to a school but am seriously considering it now based on some of these comments. I learn quite a bit from analyzing the physics behind motorcycles and cornering..(read that as throttle control and lean angle, tire pressure, heat) GREAT STUFF I TELL YA!!!

See you at Nashville or at the bash...

 

[megawatt]

You would see blue rubber if it was a heat cycle issue. Trackday tires are best starting out the season with new rubber.

Street, strip or touring tires should not be over two years old when placed in use. Especially if your doing high performance riding like on a trackday. That does no mean two years of ownership, its two years from date of manufacture. Look on the side of the tire there is a date stamp on it, all tires have this date. From memory it should be xx/xx and you read it as year/week of creation. So what is the manufacture date of your tires you might find they are 4 yrs old.

Ever wonder why some internet sites can sell tires at a very low price? Because in many times they are old in manufacture date but new in thread depth. This is one benefit to purchasing tires from some place where you get to see them before purchase. That being said I buy 90% of my tires online and hope they are not too old.

 

[GeorgiaGixxer08]

durn bridgestones. funny my buddy wrecked his 600 not to long ago goin slow around a not so sharp curve..at all. did alot more damage though. glad u and the bike were ok.

 

[zukracer]

Keith, it was gravity that caused it... you tease her enough jumpin outta planes all the time she figured you had your chute on and were ready

seriously probably was what others said, but hey you walked away and the bike is repairable and ya learned something

 

[Tufbusa]

Couple of quick points I can add:

I was at a Thunder Hill's Jason Pridmore School two years ago and dunlops very own tire guru Jim Allen was there as well. I ask that infamous question to Jim of how many heat cycles is too many. Jim responded with, "Heat cycles are a thing of the past. All modern day tires produced by the major manufacturers will be long worn out prior to heat cycles having an effect".

I'm not sure I'd agree with Megawatt on the two year thing. I've ran tires that were past the six year factory guarantee and they worked pretty dang well. Certainly not enough difference for the average rider to notice. Although, I would preferr a tire fresh out of the mold over one six years old.

 

[megawatt]

I'm not sure I'd agree with Megawatt on the two year thing. I've ran tires that were past the six year factory guarantee and they worked pretty dang well. Certainly not enough difference for the average rider to notice. Although, I would preferr a tire fresh out of the mold over one six years old.

Just because a tire has plenty of thread does not mean that it is up for trackday use was the intent of my post above. I use tires that are more than two years old myself. As long as they grip and are predictable for my style of riding I don't care too much on the age stamp. However, if I am looking at two of the same tires for sale I will choose the youngest tire based on the date stamp. Many people think because they have a tire on the bike for one year that its one year old. It may have been in a wharehouse for three years before ever being put on their wheel.

 

[fastblackblur]

I think your analysis of what happened is correct with #1 and #3 being the most important. Glad you managed to not get hurt. How much damage did the bike sustain and were you able to get back on and finish out the day?

 

[Tufbusa]

Just because a tire has plenty of thread does not mean that it is up for trackday use was the intent of my post above. I use tires that are more than two years old myself. As long as they grip and are predictable for my style of riding I don't care too much on the age stamp. However, if I am looking at two of the same tires for sale I will choose the youngest tire based on the date stamp. Many people think because they have a tire on the bike for one year that its one year old. It may have been in a wharehouse for three years before ever being put on their wheel.

My apologies! I read your post as a tire past two years was undesireable.

I agree with you!

 

[skydivr]

I had to ride my Busa rest of weekend busted clutch handle and shift lever no big deal light damage glad my experience can help other riders on my iPhone hard to type

 

[racerV]

I did my 1 and only track day at Grattan in Michigan on my stock tires and they were fine. In fact, I was the only one out of the progressive beginners group that didn't crash. Was the 1st time I had ever seen rubber ball up on a tire, I was like...Is that normal? LOL! I have learned a lot since then

 

[Domoe]

did you have the clutch pulled in when you went down? I don't even know how to ride and I know you did it wrong just from watching totwII twice. when you went down you should have been on the gas. thanks for posting so bums like me can learn, glad you ok.

 

[jdsbusa]

Hey Keith, I can't tell if that high pitched clatter is wind noise or related to the mount you've used, but if it's wind noise chopping over the windscreen take a small piece of transparent scotch tape and place it over the mic on the camera. You'll still get normal engine sounds through the tape but it buffers out the wind noise.

 

[StromBusa]

Goin too slow I think.... Bent front rim? Something choppy about the ride.