Triumphrat

drmuela · 04-13-2006

Hi everyone,

Ten days ago I was riding at Cheste (very nice race track near Valencia, Spain) and I fell down at the end of the main straight line. Nobody seemed to see exactly what happened, but I was going still on straight line, several meters before getting into turn 1. My pride is hurt, as well as my two broken ribs, but fortunately both things heal well with time. Fixing the bike is just a matter of money (some cosmetic damage - lucky I had the frame sliders).

The point is that I can not find the reason why I fell down. I can't remember the crash as I lost consciousness when I hit the ground. Not sure if the front wheel locked or if it was the back wheel. I was in the middle of a braking, going from 240 km/h down to 100 give or take. Here is the list of the possible causes that I can think of. Many of them will be checked at the dealership when I bring the bike to repair.
Let's see:

1.- Faulty bearings caused either wheel to lock
2.- Engine sized. Was running with brand new arrow pipes and remap, but don't know about A/F ratios.
3.- Gearshift box locked when going down from 5th to 4th then 3rd.
4.- Was braking too hard and locked the front wheel
5.- Was braking too hard and suspension settings were too soft. Front fork run out of travel and a bump made the front wheel to lock
6.- Same as 5, but rear wheel starting to bounce, moved sideways and lost control

At this moment I think it was probably more my mistake or the suspension settings rather than the bike's fault, but on my defense I have to say that I've ridden at the track many times (at least 20 to 25 half hour sessions on different tracks) which makes me think it is very unlikely that I was braking too sudden or too hard to lock the front wheel while I was still riding on straight line. All I seem to remember is either the front wheel locking and moving right, or the back wheel locking and moving left, then the whole bike started moving from side to side and then thinkg I fell and lost consciousness.
Any ideas of what could have happened? Something else to check that I could have forgotten? I want to check everything before riding the bike again, because being it probably my mistake, until I'm not sure that the bike is 100% innocent I won't have full confidence to ride it again at its full potential.
Anyone has had bad experiences with unexpected wheel lockups?
Any help is welcome. Thanks to all

David

Can't wait to heal my ribs and ride again :hammer: :-D

crashmasterd · 04-13-2006

What side of the bike went down? If it was the right side, then it sounds like a classic "Highside". This happens when you lock the rear tire (for whatever reason) and then let off the brake lever and the rear tire gains traction again. This is not a mechanical problem, but rather rider error: i.e. too aggressive rear brake usage. It can happen so quickly you don't realize it.

Another possibility is downshifting too many gears and sliding the rear tire. I find this less likely.

I doubt it is anything to do with the front end locking up, or a bearing issue.

Sorry to hear about the ribs, and I hope you heal up quickly.

[ This message was edited by: crashmasterd on 2006-04-13 06:36 ]

planB · 04-13-2006

sorry to hear about your crash.
More than 99% of the crashes on track are "someones" mistake, and not the bike itself...
From what you wrote, my guess would be going down in the gears AND using your rear brake too much at the same time.

I had a similar crash with my CBR600rr at the end of a long straight line, last yearat Francorchamps. Two guys behind me saw locking up the rear, which caused to lose the front as well, and me hitting the track so hard I shattered my collarbone on 5! places, and collapsed my right lung...
Luckily I am back in the saddle again, and learned from my mistakes

I hope you 'll heal quick !!

Geof3 · 04-13-2006

Sounds like a high-side to me too. Too much rear brake, tucked the front and caught traction all at the wrong time. I seriously doubt the things you listed are the issue.

Geof3 · 04-13-2006

Another thought... What tires were you on? Age? How long were you into the session?

kuhlka · 04-13-2006

A good high side would probably be enough to knock your ass out quick too!

brettmess24 · 04-13-2006

You guys dont even know what a highside is.

A highside has nothing to do with your brakes.

A highside usually happens while on the gas mid corner the wheel spins then suddenly grips and shoots you to the moon.

He was going in a straight line so it must be something with the bike :hammer:

[ This message was edited by: brettmess24 on 2006-04-13 17:05 ]

crashmasterd · 04-13-2006

Quote:

On 2006-04-13 17:03, brettmess24 wrote:
You guys dont even know what a highside is.

A highside has nothing to do with your brakes.

A highside usually happens while on the gas mid corner the wheel spins then suddenly grips and shoots you to the moon.

He was going in a straight line so it must be something with the bike :hammer:

Sorry to burst your bubble here Brett, but what you described is a "Lowside". Technically a "Highside" is all about the back brake, and a "Lowside" is when you spin the tire out from under you.

Skydakine · 04-13-2006

My vote is with the high-side theorists. When I was a teenager with more testosterone than developed brain cells, I lost control of a Vespa motorscooter doing 65MPH on a farm road by braking too hard for a turn and locking up the rear wheel. I had just a hint of a lean towards the apex of the turn which was enough to cause a skid to the outside of the turn. When I felt the rear coming around, I relaxed the rear brake pressure a little and the rear wheel regained traction, even though I didn't add power, and I was immediately launched into a barbed wire fence. It happened in a matter of one second. I learned from my mistake and I hope you do too. Here's hoping you have a speedy recovery.

brettmess24 · 04-13-2006

DOH :-D