Thursday's crash data from the "flight data recorder" aka the "black box" aka the gps

[rolker]

I had my gps strapped to the tail logging at 5Hz when I lost the brakes and ran into the tire wall outside of T6.

First, here's that session's data displayed in Google Earth.



Now, here's a graph of my speed for the last lap and a half:



So, the Y axis shows speed in MPH while the X axis is time. (The label is incorrect, it looks like the units are seconds).

So the first peak on the left is my brake point for T1, the next peak is the brake point for T3 while the next one is for the bowl. The following peaks are T9 and T11, followed by another run down the front stretch.

Comparing the third peak, my last successful pass through the bowl with the last peak, my not so successful rapid stop out the bowl, I notice a few interesting details.

That little spike that appears after the last peak is probably from the tail accelerating past the nose as the bike flips over having hit the tires.

The slope of the last peak isn't as steep as from the previous pass, indicating that some brake power was available, but not as much as usual. This agrees with the marks on the one recovered pad, that seems to indicate the pad(s) slid out about 75% of the way, but still provided some reduced stopping power.

The slope of the last peak does steepen at about 75 MPH, presumably due to slowing down going through the gravel trap. Finally, things come to an abrupt stop at about 65 MPH.

This is scary shit...

["Dangerous" Dan K]

Wait, you're doing 75 in the bowl? Or am I being an idiot. I was curious my speed through there...

VERY glad you are OK buddy. I was thrilled to see you Monday (although you probably figured that out when I jumped through your truck window for a hug)

[brady]

I'm surprised the gravel didn't slow you down more, is that thing so light it skips across the top like a Jesus lizard?

[tls25rs]

Definitely not as steep a slope on your decel into the bowl on your fateful lap!

Good to see that there was at least some decelertaion in there before you hit the wall. Do you think that some of that deceleration could be from where the hill transitions from a down hill to an uphill more than limited braking from what little your pad was contacting the rotor, or does the deceleration occur at the "normal" point where you would expect it to?

It's been said many times but, glad we can sit here and disect/discuss this incident rather than the alternative. See you at the track sometime soon!

Joel

[rolker]

Wait, you're doing 75 in the bowl? Or am I being an idiot. I was curious my speed through there...

Well, I didn't successfully do 75 mph in the bowl... that was the speed at which I believe I transitioned from the pavement to the gravel. If you look at the third peak from the left, that's my normal speeds through that section. I peak at above 80 mph after coming out of T4, and slow down to around 40 mph before driving out of T6.

I suspect you do more than 40 mph going around the bowl. Remind me next time we're at the track and I'll hook you up with a black box.

VERY glad you are OK buddy. I was thrilled to see you Monday (although you probably figured that out when I jumped through your truck window for a hug)

Oh, I felt that hug! I had just encountered a tire wall at 65 mph a few days prior, so my body was (and still is!) a bit sore! It was truly heartwarming seeing all the support and well wishes I got from the racing and track day community.

[rolker]

I'm surprised the gravel didn't slow you down more, is that thing so light it skips across the top like a Jesus lizard?

Actually, I think that might be partially why I didn't slow down much, the bike probably didn't sink much due to both being light and skimming over the gravel at 75 mph!

I don't remember how I reacted, but I suspect I probably got off the brakes as I transitioned off the pavement into the gravel. If that is indeed the case, the gravel itself slowed me down more than the partial brakes I had on the pavement.

[strgt]

Wow, thats a crazy situation. Did you ride the bike to the wall, or did you fall off before?

[rolker]

Definitely not as steep a slope on your decel into the bowl on your fateful lap!

Good to see that there was at least some decelertaion in there before you hit the wall. Do you think that some of that deceleration could be from where the hill transitions from a down hill to an uphill more than limited braking from what little your pad was contacting the rotor, or does the deceleration occur at the "normal" point where you would expect it to?

It's been said many times but, glad we can sit here and disect/discuss this incident rather than the alternative. See you at the track sometime soon!

Joel

That's a good observation, the hill transition could be the reason the slope steepens and I had more deceleration. I'll have too look deeper into the data to try to confirm this.

You were on the scene picking up the pieces right? What can you tell me about the crash scene? Do the marks in the gravel and were the bike was found agree with the track shown in my Google earth image? Do the marks in the gravel show if I stayed upright all the way to the tires or did the bike dig in and flip prior to hitting the tires?

Anyways, thanks again Joel for helping take care of things after the crash. It's very much appreciated!

[rolker]

Wow, thats a crazy situation. Did you ride the bike to the wall, or did you fall off before?

Good question! I don't remember. Actually, I don't remember anything about that whole session...

[Kurlon]

I've seen pictures of the gravel trap and barriers right after your crash. How can you expect me to believe an RS125 with a moderate fuel load crashed there without leaving parts everywhere, or scarring the barrier?

You can't, it's crazy.

Obviously this is an inside job by NHMS!

[Doc]

This is some awesome intel Roland. I gotta have you do some datalogging for me.

[kb1]

OWE! That's all I have to say.

[rolker]

I've seen pictures of the gravel trap and barriers right after your crash. How can you expect me to believe an RS125 with a moderate fuel load crashed there without leaving parts everywhere, or scarring the barrier?

You can't, it's crazy.

Obviously this is an inside job by NHMS!

Yeah, I'm starting to believe that brakes had nothing to do with it. I'm think I got taken out by a *SAM missile.

*SAM: SurfAce-to-Motorcycle

[rolker]

This is some awesome intel Roland. I gotta have you do some datalogging for me.

Come and find me next time we're at the track and I'll see what I can do.

[rolker]

OWE! That's all I have to say.

I'm VERY lucky that I'm not still in the hospital or worse... I hadn't realized how fast I was still going on impact until I saw the data.

[scubasteveRR]

have you figured out why the brakes failed?

was it a line and loss of fluid or was it a mechanical faliure of the actual brake?

[rolker]

The pin holding the pads in was missing. I'm not sure if it broke or fell out due to me unknowingly messing up last time I changed the pads towards the end of last season. The one big mistake I made was to not check them that morning before I went out on the track.

[SVRACER01]

Wirelessly posted (HTC EVO "DROID" : Mozilla/5.0 (Linux; U; Android 2.2; en-us; Sprint APA9292KT Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1)

I want to use the black box

[tls25rs]

You were on the scene picking up the pieces right? What can you tell me about the crash scene? Do the marks in the gravel and were the bike was found agree with the track shown in my Google earth image? Do the marks in the gravel show if I stayed upright all the way to the tires or did the bike dig in and flip prior to hitting the tires?

As far as the scene goes, I really didn't see all that much of how the gravel was etc. I was outside the fence looking through to where the ambulance crew, Scott James Racer #932, Tom Blanchette and the wrecker guy were. They were just about done clearing the scene when we got there so we just turned around and headed in to the the IMC to check on you.

Your Google map however does indicate an accurate location of the impact. If I remember correctly the impact zone was roughly 10-20 feet, maybe slightly further, to the right (when viewed from the track surface) of where the walkway up to the turn 6 bleachers meets up with the wall as it reaches the bottom of the bleachers. Hoefully that is clearer to you then it sounded to me after writing it.

Joel

[PainfullySlow]

I am mixed with feelings of "holy crap so glad you are alive" as well as "that is some of the coolest data logging I have ever seen" :-p

[rolker]

I want to use the black box

Come and find me next time and I'll see what I can do...

[rolker]

As far as the scene goes, I really didn't see all that much of how the gravel was etc. I was outside the fence looking through to where the ambulance crew, Scott James Racer #932, Tom Blanchette and the wrecker guy were. They were just about done clearing the scene when we got there so we just turned around and headed in to the the IMC to check on you.

Your Google map however does indicate an accurate location of the impact. If I remember correctly the impact zone was roughly 10-20 feet, maybe slightly further, to the right (when viewed from the track surface) of where the walkway up to the turn 6 bleachers meets up with the wall as it reaches the bottom of the bleachers. Hoefully that is clearer to you then it sounded to me after writing it.

Joel

Makes sense to me! Thanks!

[rolker]

I am mixed with feelings of "holy crap so glad you are alive" as well as "that is some of the coolest data logging I have ever seen" :-p

I kind of feel the same way, the more I look at the data and realize how fast I was still going, the more I'm amazed at how little damage the bike and I suffered!

[RyanNicholson]

Thats crazy, glad you're ok man.

I'm kind of a data nerd myself, and its fascinating to see... but make sure you don't over analyze a freak accident. It doesn't seem like it bothers you much, but I know some people think about crashes and the lessons to be learned so much that they struggle to get their "fast" back after the fact.

[rolker]

Thats crazy, glad you're ok man.

I'm kind of a data nerd myself, and its fascinating to see... but make sure you don't over analyze a freak accident. It doesn't seem like it bothers you much, but I know some people think about crashes and the lessons to be learned so much that they struggle to get their "fast" back after the fact.

Don't worry, I'm just digging into the data to make up for not remembering a thing. I'm just sharing my findings so that all other geeks like you can enjoy them as well. About getting my "fast" back, I don't think I ever had it, but so I don't gain too much "slow", I did make sure to get back out there on Monday to face T6 again and start preparing for round 2.