nomapnocompass said:
Nothing suspicious about the Hesjedal crash except for the lack of intelligence and knowledge of some on this forum.
Another clip illustrating the principle of conservation of angular momentum in the rear wheel, this time during a TTT crash. The bike also suddenly flips direction at the end.
https://www.youtube.com/watch?v=q7TWDNhWDlY ( 0:42 seconds in )
Yeah, I'm with you.
I had a bit of fun earlier with 'I'm drinking beers and see what I want to see and work the rules of physics backwards to fit my bias!'
But in serious, I don't think this video is conclusive, or even all that suspicious. I think it is incomplete, without context, and impossible to evaluate.
There are too many 'unknows' to say this video is 'proof' of anything.
But people look at the video and fill in the unknows with what they 'want' to see. Or make subconcious assumptions and are led astray.
Normally you sit down and say - here are the possible scenarios that could cause this (gravity, momentum, power from the unmotorized wheel, power from a motorized wheel, combinations of the above). Then you try to asses - or calculate - is gravity enough to make a bike slide down a hill?
But with so many unknowns, you can't really evalute the scenerios.
I think it's better to look at the video and say 'from this source, I can't determine x,y,z.' When enough key facts can not be determined, all you can say is 'this source isn't conclusive, I can not make a determination.'
We don't know
1) the speed Ryder was traveling
2) why he crashed
3) the coefficient of friction of the road
4) if the coefficient of friction of the road is consistent
5) the grade of the road
6) the cross slope of the road
7) if 5 and 6 are consistent
8) the weight of his bike and how it is distributed
9) if Ryder 'kicked' the bike forward when he unclipped
10) how much the video is 'distorted,' because it's shot from a moving motorbike.
If Ryder was riding slow, on a well tractioned road, that was uniformly flat - it'd be weird for his bike to move / slide / spin.
If he was traveling fast on a slippery road, with a lot of slope and cross slope - it would be normal to see all kinds of movement.
My background is track racing, so I've seen bikes - and riders - do much crazier things then this. If you've ever seen a cyclist get caught in a pile up, spin 'up' the track, but his bike spin 'down,' then he pinballs along the boards long after everyone else has slid down, finally slide head first down the banking, slide across the apron and finally stop in the grass - you don't forget it. (He only suffered a mild concusion.)