[Theoretical] How to do bunny hops.

[fractoid]

First up, just to be clear, I'm not saying I'm some mad stunta givin' you tha real deal. I'm merely a curious guy who knows enough engineering dynamics to be dangerous. If anyone is confident enough to actually try (or have tried) this I'd be curious to hear. Alternatively, if it's bullshit then tell me and I'll flag it with a giant "PS. THIS IS WRONG" at the start so people don't try it.

Anyway, there was a thread a couple of months ago saying "what the... O.o" and posting a video where at one point, a guy does a bunnyhop on a sports bike. Thinking about it a bit, this seems relatively easy in principle, using the same principles which motocross riders use to control their bikes' orientation mid-air. You just need to be very comfortable doing wheelies. This approach isn't using your own strength to muscle the bike off the ground as you do a BMX or mountain bike. It makes the bike do the work.

Step 1: Accelerate to some specific speed which depends on the weight of your bike, the weight of your rear wheel, the alignment of the stars, the weight of your testicles, and the whim of the gods. I'm guessing at least 30-40km/h. Ish. Load up the rear suspension as much as possible by applying moderate front brake and balancing the throttle to maintain speed.

Step 2: Pop a mad wheelie. Kick against the pegs to push yourself upwards, then as the bike is at it's lowest and starting to bounce, release the front brake. Pull the front up as fast as possible, much quicker than would normally be healthy for a sustained mono. You want the bike's center of gravity to be moving upwards rapidly.

Step 3: When the front wheel is up by about 40 degrees, yank the clutch in and mash on the back brake. The point here is to check the bike's angular momentum, using a combination of the wheel's contra-rotating angular momentum and some braking on the road. If you do it right, the bike is now no longer rotating, but still has the upward momentum from step 2.

Step 4: You're now in the air. If you're lucky the bike's there with you and you're happily flying in a controlled bunny hop. If you're unlucky, you're probably going headfirst towards the ground, chased by an angry motorcycle. Assuming you're lucky, you can control the bike's attitude with the throttle, as if you're doing a wheelie (although it'll be much less responsive since you're only using the rear wheel's angular momentum as reaction mass, rather than the ground).

Step 5: As the rear wheel approaches the ground, clutch out and rev moderately to cushion your landing.

If you get it right it looks like this:

[Brendonv]

wow dam thats cool.

[Barfridge]

Sounds so easy...

[MattyA]

I think you forgot to emphasize the importance of loading up your rear suspension.

[fractoid]

I think you forgot to emphasize the importance of loading up your rear suspension.

Hmm... I probably did. Shall add it.

[Guil]

It's not theoretical if people are already doing it

[bigmak]

people been doing them for ages now. go to stuntride.com and post there. sure theres a few people who can help u out

[bikermouse]

funny write up dude crazy concept and props to anybody who can do it (x10 on a fat gsxr)
and guil, i believe fractoids theory lies in the execution..

[Rich]

I agree with everything you wrote but would add that also grabbing the front brake to stop the front wheel turning while in mid air will transfer that force to lifting the back...

Edit: after a little think I reckon stopping the front wheel turning would be better than stopping the back wheel turning...

Although stopping the back will seem to do the same thing it will do it by lowering the front...watch the motox guys flying a bike, shutting the throttle or touching the brake doesn't raise the back, it lowers the front...

Stopping the front will lift the back...

See what I mean...

[shades]

Interesting, yet strangely pointless.

[bigmak]

Quote: Milt IV (stuntride.com)

klassik explained it to me like this-
gas it hard in first to pow pow, no clutch up

as its pow powin up the rear spring is preloading

once the spring is preloaded close the throttle hard and grab a handfull of clutch and hand break at the same time while simultaniously throwing your body weight forward. you gotta grip the bike with your knees moto style.

the concept is really easy and it just like bunnyhopping a bmx but getting the timing right is what its all about and if you dont have that then your back tire is only gonna get an inch of the ground like mine.

[bikermouse]

pic no worky,