VFR 800 Question- Serious Replies Only Please

[brruss]

My brother was killed 3 weeks ago on his VFR 800. Our family went to the scene of the accident and had a look at the intersection where it ocurred. The police painted lines on both ends of the skid mark. My question is how can his speed be calculated? I'm just curious, so I can get it straight in my head. The mark was approximately 15 feet long. The bike weighed 557 lbs. according to the spec. sheet, and my brother weighed about 350lbs.(obviously much to big for that kind of bike). Ignoring that he skidded into the vehicle, at least, how fast was he traveling for 900 lbs of bike and rider to skid that far? What is the braking coefficient for these bikes? Unfortunately, his bike struck the vehicle and flew end over end landing about 30 feet away and totaling the car. We were told it happened instantly for him. I would appreciate any remarks or feedback. Just need some answers. Thanks.

[hotwheels]

Not sure. I would awesume the speed would have to be calculated from the damage and distance after impact. The skid marks of 15 feet dont say a whole lot. Did you post the same question at www.vfrdiscussion.com , you may have a better variety of answers by getting to more people. Where was your brother from? If he was on vfrd I believe I know about it. Hope this helps, sorry for your families loss. Godspeed.

[WhiteKnight]

I don't know the exact equation, but from the length of the skid marks I believe the police can determine just how fast a vehicle was traveling.

I found this little atricle which give a little explenation. It is not an all encompasing piece, but may give a litle insite.
Skid Mark Analysis

and a PDF file: http://www.harristechnical.com/articles/skidmarks.pdf

Hope these help and my condolences to you and your on the loss of your brother.

[VFRstar]

I havn't been on these forums long, and mostly lurk.

I'm a Deputy Sheriff. I could give you several formulas to calculate speed. Skid marks are easy, but only when you have a start and an end, even if it crosses from pavement to gravel to grass. But when you have a skid mark that ends in an impact like you described, the skid mark is almost useless other than determining reaction times.

If the skid mark is an arch, a speed can be determined by calculating a "Critical Curve" regardless how the skid mark stops.

In a case you have described, it would require an expert reconstructionist to calculate weights compared the the depth of the destruction of the vehicle and the distance the bike traveled to even estimate a speed.

In the case of a fatality, they may very well be doing this. As family you can request a copy of the report from the agency who did the investigation once it's complete.