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Two different ways he attacked it...
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Some guys were hitting the first bump, and clearing that whole section.
I think he was 450ing the whole section.
Once again...go take a physics class and learn just a minuscule bit about Hookes law.
Not saying that the spring always returns energy to the system, but it's definitely possible. In the case of the photos, he using his body weight to keep the rear end fully loaded past the crest of the jump and prevent the spring from unloading.
Hookes law
Must be Hollywood !
Second half of a double, ...I can see that.
https://biglenny.gets-it.net/i/seatbounce_no.jpg
Pit Row
https://biglenny.gets-it.net/i/seatbounce_no2.jpg
I received it as two different photos on two different jumps...I don't know why I just couldn't see it.
Thanx Void...And yes, today I ride a 4-stroke...That's what they give me.
Chad's technique on this jump is perfectly described and shown in this clip...
It only describes force. The spring pushes against parts of the bike, not the ground.
The system is what we are interested in, and it contains a damped spring, not a perfect spring.
Plus you want to do an energy balance, and set the system up right, not calculate forces.
We used to make fun of you guys in engineering school.
The subject technique is the opposite of a seat bounce. He's getting his CG high instead of low. This minimizes the amount of work required to get over the jump. Less work required equals less energy consumed. Its done to stay low and maintain horizontal momentum.
"Seat bounces" are when you get your weight low, forcing the bike/rider to require more work to get past the jump. Mork work means more energy consumed (actually, translated to increase vertical momentum).
To seat bounce, what you are doing by staying low on the face of a jump is is forcing the system to translate more horizontal momentum to vertical. You could do it without a spring.
The amount of energy released by the spring is equal to the amount of energy consumed in compressing it. The balance is zero. That's why airplanes have wings and engines and not springs.
Notice in the pics, the wheel is at the rear fender, but Reed is standing up. The rebound is exactly the same as if he were sitting and leaning back to "seat bounce." It is impossible that in one case the bike stays level and in one case it leaps up due to the spring when the wheel does exactly the same thing each time relative to the bike.
Its amazing how far an incorrect explanation of physics will go!
I'll be right back, I'm going to get some popcorn.
Everyone believed the magic spring lifting nonsense until I called BS.
I changed history!
Post a reply to: Seat Bounce. Fact or Fiction?