Motorcycle crash physics question

[txpitdog]

Didn't appear to have sliders, unless the radiator, exhaust, fairing, front rim, and his skinless body counts! I'm glad he appeared be a jobless dumbass, because his bike was trashed to the point I don't think he can afford to fix it. One less speeder down our busy street.


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[Rubi513]

Glad the young man is o.k. and no one else was hurt.
Hopefully it was a valuable lesson learned.

[mmoses]

They can slide a long way. Newton's first law.
Plus sometimes they dont go down.

https://youtu.be/4w3I-pkrY3k?t=16s

[hoythitman]

If it landed on the right side like mine did at a low speed drop, it pinned my throttle and walked the bike about 100 yards down the road.

[easeup]

he is most fortunate that he or the bike missed a brick mailbox during the slide.

[niceg3s]

Depends. At 35 mph stopping distance when braking is 136 feet. Doesn't seem fast, but it is. The amount of friction of the bike sliding is probably a little less efficient at stopping, and he may be still giving it throttle unintentionally. Did you physically go out and measure the distance?

[xman59]

Based upon known data in my area I come up with approximately 52mph. That is assuming 300 feet of solid slide. Believe it or not, weight is not a factor in stopping distance, only braking efficiency.

weight is a factor in the formula for the drag factor, without a drag factor you are guessing at speed because you have an incomplete formula,,,

braking efficiency is an individual thing affected by the tires, road surface weight, tire wear and material, and actual breaking ability of the vehicle... also "braking efficiency" only works when it remains on its tires, drag factor applies to any materials including sand, mud, gravel dirt, water and those materials when they are on a road surface.......

[Bowen Aero]

Some suicide jockey on a Harly Daverson tried punching a hole in a guardrail on 1283 when I went by early this morning. DPS, Sheriff, Game Warden, Ambulance, Fire Department.

That was just before another Harly rider tried passing in a no passing zone on a narrow road and was coming at me head on.Good thing I have big rotors and steel braided brake lines.

[bagger1903]

Gad he wasn't hurt and did not hurt anyone else.

[farfel]

At least he was prepared. Those Shoei's ain't cheap.

[twostepct]

I understand that weight is a factor if you are using the bike as a drag sled to solve for the coefficient of friction but that wasn't a part of this. Also braking efficiency is based upon the mechanical capabilities of the vehicle and the distribution of weight. The deceleration factor is based upon the specifics of the vehicle. If skid tests are conducted with a vehicle to obtain a surface friction value and then weight is added to the vehicle, there will be no appreciable change.

weight is a factor in the formula for the drag factor, without a drag factor you are guessing at speed because you have an incomplete formula,,,

braking efficiency is an individual thing affected by the tires, road surface weight, tire wear and material, and actual breaking ability of the vehicle... also "braking efficiency" only works when it remains on its tires, drag factor applies to any materials including sand, mud, gravel dirt, water and those materials when they are on a road surface.......

[drop dead fred]

Spork

[xman59]

Based upon known data in my area I come up with approximately 52mph. That is assuming 300 feet of solid slide. Believe it or not, weight is not a factor in stopping distance, only braking efficiency.

I understand that weight is a factor if you are using the bike as a drag sled to solve for the coefficient of friction but that wasn't a part of this. Also braking efficiency is based upon the mechanical capabilities of the vehicle and the distribution of weight. The deceleration factor is based upon the specifics of the vehicle. If skid tests are conducted with a vehicle to obtain a surface friction value and then weight is added to the vehicle, there will be no appreciable change.

first you say it does not matter then you say it does........ the question was "how fast was he going" you can not leave the weight out, period! because it does matter,, and said so in your second reply,,,, anything without weight is a guess, or estimate,,,

[twostepct]

So... Is it safe to believe you've never used published data for for a reconstruction then? If you have you would understand that you are using data in a formula, skid to stop in this scenario, that is completely independent of the weight of a unit in your investigation. Also, remember that there is no need for weight in a skid to stop formula. So I'll say again, the weight of the motorcycle only comes into play if you use it as a drag sled. Absent of that and using published data, it does not.

[JHT]

If he dumped the clutch and had it pinned when he did it there's no telling where it could end up.

The road rash he has will last a few weeks. I bet you won't see him on your street again just outta karma.