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Discussion Starter · #1 ·
I was talking to a much more experienced rider that I saw on campus one day and noticed that he could really smoothly and seemingly effortlessly leap into the air with his full suspension free ride rig. I was asking him for some tips and he mentioned that one can actually hop higher on a hard tail (what I ride) than with a f/s bike.
Now dispite my best efforts I havn't really been able to get the back wheel up more than 6" max, and it just seems like it would be so much easyer if I had a mushy back end to spring from.

So is this guy right (meaning I need more practice!), or wrong, or is it one of those "it depends" things :D

I've ridden all my life, but I'm fairly new to techincal type riding.

Thanks for any input! :cool:
 

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If you tune your suspension like a pogo stick then maybe it could help you bunny hop, but then it would buck you off on trails. Just keep going with what you have and remember that technique is impressive because it doesn't develop without effort.
 

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You know, you just keep working at it. When i use to ride BMX my bunny hops were really low, the more i worked at them the more i could do. It started of like a cm, then i worked up to a curb and stuff. we cant exactly tell you how to make your bunny hop higher, just because people use to tell me how to do it, and i just couldnt, until i learnt for myself. All you need to do is keep working at it, and it will come.
 

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In general, yes, it is easier to bunnyhop higher on a hardtail. If you think about what a shock is supposed to do, it makes sense. The job of a shock is to absorb energy.... actually, it converts kinetic energy (motion) into heat energy. When you do a bunnyhop you explode upward with your legs (kinetic energy). If you're on a FS bike, some of that energy gets gets absorbed (or converted) by the shock. Therefore, you have lower vertical kinetic energy when you leave the ground, and since energy is conserved that kinetic energy gets converted to potential energy (moving a mass to a higher elevation), you get less elevation at the peak of your hop.

If Ebh is the energy you put into the bunnyhop and Eshock is the energy absorbed by the shock, then if we ignore other minor losses (such as the viscosity of air and loss in the tires) the energy equation is as follows:

eq1) Ebh - Eshock = Mass x Change in height

and from equation 1 we can derive the equation for height:

eq2) Change in height = (Ebh - Eshock)/Mass

From equation 2 you can see that the change in height you are able to achieve is directly related to the amount of energy absorbed by the shock. If you're on a hardtail Ebh is zero and height is maximized. You can also see that height is inversely related to the mass of the system (bike + rider). Therefore, losing weight off the bike (or yourself) will also increases height.

This is a simple model and it assumes that Ebh and other things(like technique) don't change.

End of lecture. ;)

FRC
 

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Discussion Starter · #6 ·
lol, thank you professor chicken! I should have thought of it that way (I've been through enough physics). Going over the handlebars twice my last ride must have done something to my ability to rememberiz stuff from school ;)

well back to practicing/experimenting
 
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