Tuesday Tip: The Sponge Theory

Intro and Photos by Garth Milan

When you’re doing a moto with your buddy at the local track, nothing is more frustrating than a severe case of arm pump just as you’re ready to toss him/her over the next berm. The dreaded curse of arm pump is caused by a number of factors, but one of the biggest precursors to pumped veins in your forearms and hands are chopped up, rough braking bumps on the entrance of corners.

Short of jumping on the tractor and smoothing the track out yourself, unfortunately there’s not much you can do to avoid braking bumps; they’re a sad reality of motocross. If you’re sick of your arms looking like Popeye’s, though, there is a way to combat the “bump equals pump syndrome. With the proper form and technique, stars like David Vuillemin are able to minimize their arm pump on rough sections by loosening up, using their bike’s suspension to their advantage, and soaking up the harsh jolts like a sponge.


We spied Team Yamaha’s David Vuillemin recently on one of the roughest sections of the bumpiest tracks we know, and couldn’t pass up the opportunity to ask him for his advice. Cahuilla Creek is known for its brake chop, and the nasty bumps pictured were on the entrance to a corner with loose, sandy conditions. We’ll let the Cobra take it from here…


“When coming up on a rough section like this, the first thing you need to remember is that you want your bike in a gear higher than you might think you need to be in. I enter this corner in third, whereas a lot of the riders I was watching came into it in second. This is no good; if you enter in a low gear, your bike will be doing too much engine braking. This will cause it to swap from side to side, make your front end go too low in the stroke, and your suspension will not react how it should.

“Besides being in a higher gear, the next best piece of advice is to relax and loosen up! If you’re coming in hot with a death grip on the bars, of course you’ll get arm pump. Instead, let yourself flow and be natural on the bike.


“It makes a huge difference if you consciously remember to grip the bike harder with your knees and legs. Squeeze it hard here instead of with your hands, and you’ll have much more control. Your legs are stronger and do a better job of stabilizing the bike, plus they don’t get pumped up as quickly.

“Make sure you are smooth with the throttle and brakes, too, and stay on top of the bumps as you come in. Keep your weight towards the back of the bike and try to never let your front end dip down too much; this can cause you to go over the bars.


“If you do all of the things I just mentioned correctly, your arm pump should be far less than it was. But don’t get too lazy out there. You still need to shift if you want to do the corner perfectly and have fast lap times.

“Since the turn that follows these bumps is pretty sharp, I need to shift down to second gear in the middle of it. As I mentioned, I enter the turn a gear high in third, but once in I shift to second in order to get plenty of traction in the sand. The trick is waiting. Once you get back up to speed and are exiting, shift back up again for the approaching straightaway.