Fore-aft balance when jumping


The comments for The end of flat pedals at World Cup downhills? tracked into this subject, and I think it’s pretty interesting. Check it out:


John K. Says October 3, 2012 @ 8:45 pm

Hey Lee I wonder if you would comment on another “weight-forward” situation. I’m a firm believer in the heavy feet-light hands philosophy, and that one tip has taken me further then I ever thought I could go with my riding. So thanks for that.

When jumping, however, I’m feeling more balanced and “poppy” when I shift my weight forward as I approach the jump. It seems that by shifting my weight forward and loading my hands, I can really control the pressure on my front wheel as I ride up the lip of the jump. I still pump the bike with my feet, but by weighting the front of the bike, I’m getting more pop and I’m consistently well balanced in the air.

Conversely, I’ve noticed that if I ride off a jump with no hand pressure, my front tire will sometimes drop as soon as it goes off the lip, while my back tire pops nicely off the jump. This leads to that dreaded forward rotation in the air, and occasionally an OTB experience. I used to think these experiences were a result of being too far forward on the bike, but I’ve now come to realize they are result of not loading the front wheel sufficiently into the lip of the jump.

Anyways, appreciate your observations/thoughts. Cool article for sure.


Hey John,

Thanks for the great question.

I see the dreaded airborne forward rotation every day at Valmont Bike Park here in Boulder, CO. The jumps are built so well, most riders have no idea how close they are to broken collarbones.

So far this year, I’ve taught more than 200 people the fine art of braaap. The more I teach, the simpler I try to make things. Simple is good. Let’s keep this simple:

How it should be

Imagine the trajectory your bike would follow over a big, perfectly shaped roller. Actually, check out the below diagram.

A well built jump is just like that roller, except the top is missing. While you’ll be loading the lip to catch air, your body should have the same fore-aft balance as it does on the roller.


The dynamics get complex, but if the jump is built correctly, sweet jumping technique comes down to heavy feet and light hands — plus some power from your hips.

What goes wrong

Most riders hit jumps too far back. This is a defensive position, and it’s often involuntary. If you do this, the rear wheel will hit extra heavy, and you will get bucked forward.


If you’re going fast and/or the transition is abrupt, your bars will come back toward your hips very quickly. Some riders who reach the jump in a balanced position are too stiff to let the bars move freely. They get pushed back, and then they get bucked forward.

It can help to actively pull the bars toward your hips while you’re going up and push your bars away while you’re going down, but the ultimate goal is a peaceful centeredness. Heavy feet, light hands. Watch the best dirt jumpers. They look lazy in the air, don’t they?

Learn more

Read these stories, and the links on these pages:

https://www.leelikesbikes.com/shallow-vs-steep-jumps.html

https://www.leelikesbikes.com/controlling-mid-air-rotation.html

For a good overview of riding technique, check out Mastering Mountain Bike Skills.

For a very detailed look at pumping and jumping technique, check out Pro BMX Skills.

For the ultimate kung fu experience, take a clinic with me. I’ll get you dialed.

Rip it!

Lee


Know more. Have more fun!

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8 replies
  1. Scott says:

    Thanks Lee. I knew to try and compress into the lip, but I think I’ve been jumping stiff arms and legs. Letting the bike come up under the body looks like answer. Would love to do a clinic, but you’re a long way from Australia. Will have to make do with the book. Loved the “Not good” in the illustration!

    Reply
  2. Jman11 says:

    Wow thanks for the explanation, now i totally understand what is going on when i took tabletops, will try your advice on my next ride. Also i’ll be glad to assist at one of your clinics but also is far far away from here.

    Reply
  3. John K. says:

    As always Lee, your advice is super helpful. I think I used to hit jumps with my weight too far back, in that defensive position you speak of. Now that I’ve consciously moved my weight more forward, my jumping and confidence have improved, and I’m sure it’s because my body is getting closer to the first graphic you show.

    Lately I’ve gone back to your discussions around moto vs mtb riding styles. I’ve done some experimenting on the trails, and I’m really liking the moto style of riding for myself. I feel much more aggressive and engaged when I keep my weight forward. The trick is to move my weight forward WHILE keeping my hands light! I’ve found myself leaning on my hands a bit too much at times in this “moto” position.

    I agree that it’s best to keep it simple, but I sure like to think about this stuff… thanks again Lee.

    Reply
  4. WAKi says:

    One thing is a bit unclear to me Lee. It’s imposible to just take it staticaly like that. As the bike starts to roll up the lip your body still goes forward for a moment, therefore in a static position the force will be transfered to BB causing that neutral tick from your drawing to tip forward. If nothing is done the counter reaction will tip it back, perhaps too far.

    In terms of remaining in balance then, you actualy have to tip back a bit so that the force pushing the bike up is balanced through bottom bracket into your body. In my understanding the only relatively static way of approaching a jump is to hold the arms really stiff, so that force is transfered into the tick though arms not allowing it to tip forward. This is short sighted anyways, as at higher speeds, the counter reaction will simple tip me back and I will land on my spine.

    MY best jumps happen by driving the bike through the legs, so that it is through BB that I keep the things balanced, but I might be wrong off course

    Reply
  5. Jaroslaw (Poland) says:

    Thank you , you keep it simple and what made me a huge change and progress is that: “This is like jumping off a diving board”. Relax, hands loose, heavy feet. Ps. You’re book Mastering Mountain Bike Skills is very popular in Poland 🙂 Just great and inspiring! Love it!

    Reply

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