I've seen that video before but I've never been able to see the woman putting her foot in the spokes.DirtFace said:
foot hits the spokes, spokes pull the foot up and then push it forwards, it slams into the fork, wheel stops, endo.53T said:Even if she did hit the spokes, which is not aparent, it would not explain the crash.
regardless of what the narrator is saying, I can't see her foot going into the spokes. Her right foot continues to move down as the crash begins. I don't see any abrupt change in the movement of her feet. At first I thought there was a speed bump of something.zeytin said:53T, did you have your sound turned on while you watched the video
I've been thinking of how to explain the physic behind this video but I think you've nailed it. I don't think you could have said any better.Tim M said:I believe I've done this, in a way, many years ago, on BMX bikes. A few times, actually--once in a race just after the first jump and it knocked me unconcious for a moment. Hard to explain, but the sequence: Body mass moves forward and down in relation to bike (the bobbing), hit dip at wrong moment forcing further forward force in relation to bike, foot slips off pedal forward in front of pedal on downstroke, pedal to back of leg as foot (probably, briefely) touches ground. Foot/pedal combo seems to "stop" bike while body mass continues forward and down, and when the relationship between these actions reaches the critical point, it's over the bars. The bike damage (bent/broken fork?) is a result of pitching forward and down at the bump--the endo part. Or so it seems.