How to diagnose a crash

randomwalker · 06-16-2011, 08:39 PM

If you crash on a race track and you're not sure if it was the front tire or the rear tire that slid out from under you, are there any tell-tale signs or other clues that may help you piece things together?

**1000RR** · 06-16-2011, 08:53 PM

I would say in general that if you low sided in a turn, you probably tucked the front... Were you on the front brakes trailing in? If not, the front might have just lost traction. If your rear got sideways/squirly it would have more likely resulted in a high side.

Were you OK? How's the CBR?

randomwalker · 06-16-2011, 09:13 PM

I was on the front brakes trailing in...but it was also my 6th track day on the rear and 3rd on the front, which is what makes me wonder. The CBR suffered some cosmetic damage on the LHS, which I'm busy fixing. I'm OK, for the most part. The funny thing is that after I stopped sliding and then rolling, the first thing I did was to run over to the bike and check the lap timer...yeah...I think I go it real bad.

**1000RR** · 06-16-2011, 09:47 PM

LOL...

Assume you low sided... otherwise you probably wouldn't be so "OK"... Sounds like the front tucked on you. What kind of tires were you running? How many laps had you been out there? Are you using tire warmers? What were your cold pressures? What were your hot pressures? What kind of temps were the tires when you would come into the pits? How's the wear on the tires look? Any issues prior to that? Has the suspension been set up properly? Geometry, etc. There are plenty variables. Do you have any eye witnesses or video? Sometimes you can post on the local track's forum and maybe someone else saw you go down or had video that day.

2_stroke_bloke · 06-17-2011, 12:45 AM

This comes with experience of knowing how a motorcycle functions.

I'd start with twist of a wrist, Keith Code's book. That way, you can understand what you are supposed to be doing (and why you should do it). When you veer away from the general rules of riding, you can understand why you crashed.

For example, if you chop the throttle mid corner, you understand that you are upsetting the 40/60 rule of weight distribution.