TEN THINGS ABOUT DIALING IN YOUR BIKE’S SUSPENSION

10things-suspention

(1) The MXA way. Every new model year the MXA test riders spend months trying every feasible suspension combination. We go all the way soft. We go all the way stiff. We lower the oil height. We raise the oil height. We go to extremes to get the most out of the stock suspension components. Our goal is to help consumers find a good starting point. Now, with the new breed of complicated Showa SFF TAC Air forks on the market, the need for workable air pressures is even more critical. We know that our recommended settings aren’t perfect for every rider—because they aren’t perfect for every MXA test rider. But, they will get you in the ballpark. The rest is up to you.

(2) Balance. If the front and rear suspension aren’t working in unity, the bike will never function correctly. If your bike has a stinkbug feel or is unstable at speed, you can lower sag, slide the forks down in the clamps or lessen the high-speed compression. If your bike feels like a chopper or is having issues turning, do the opposite. An old trick to see if you’re in the ballpark (but it only works with spring forks) is to take the bike off the stand, put your foot on one of the pegs and press down. Both ends of the bike should move down equally. If one side goes down significantly more than the other, you have a problem.

(3) Feel. When testing your suspension, pay attention to the areas on the track where a setting performs well and where it falters. Your goal is to have very good suspension performance around the whole track—not great suspension on one specific portion.

Jimmy Decotis 2020 Supercross JGRMX RM-Z250

(4) Spring rate. Manufacturers select their spring rates to work with a wide variety of weights, speeds and skill levels. So, if you’re a light rider on a 450 or a heavy rider on a 250, then the correct spring rates for your weight and riding level are on a shelf somewhere.

(5) Sag. Rider sag should be the first thing you check before hitting the track. Just a few millimeters can make a big difference. Typically, most big bikes work well between 100mm and 105mm. We don’t go below 105mm, although there are riders who do. Why don’t we? Once the sag exceeds 110mm, the effect on the frame’s geometry drifts toward the weird side of the equation. Too much sag may solve one problem, but it creates others.

(6) Oil level. Adding oil to your forks reduces the air volume. Since the compression of the airspace is gradual, lessening the airspace, by adding oil, will make the forks feel stiffer from mid-stroke on. Logically, if adding oil makes your forks feel stiffer, taking oil out of your forks will make them softer. MXA tends to remove 10cc of oil whenever a fork feels harsh in the middle—and we keep lowering the oil height until we have a bottoming issue.

(7) Butterfly effect. Any changes made to the suspension settings will have unexpected effects on other parts of the bike. Changes to the rear will affect the front and vice versa. The auxiliary effects can become very confusing. So confusing that often a shock problem is really a fork issue and vice versa. We recommend keeping notes on every suspension change. The MXA wrecking crew goes to the extent of writing suspension setup numbers on the fenders so they are easily referred to.

Honda CRF450 prototype Ryan Hughes

(8) Trickery. Even the best testers in the world get tricked into feeling something that isn’t caused by the obvious culprit. Most commonly, forks that feel too stiff are often too soft. They feel stiff because they are hanging down into the harshest part of the stroke. Attempts to make them softer will only make them worse. Instead, going in on the compression will bring the ride height up to the plusher part of the stroke.

(9) Fork height. Fork height is your friend. It changes the weight bias. It changes the frame geometry. It can decrease headshake or increase turning prowess. When you slide the fork legs up in the clamps, you achieve three things:
(a) You steepen the head angle for quicker turning.
(b) You put more weight on the front wheel to soften the forks.
(c) You lower the chassis and shorten the wheelbase for quicker handling. It’s amazing how a few millimeters can make so much of a difference.

(10) High-speed compression. A lot of people tend to stay away from the high-speed compression adjuster due to lack of knowledge about what it does. It isn’t called “high-speed” because it has anything to do with how fast the bike is traveling; it has to do with how fast the shock shaft is moving. If your bike reacts poorly to G-outs or square-edged bumps, turn the high-speed dial in a quarter turn. This will increase the damping and slightly raise the rear of the bike once in motion. If the bike feels harsh on G-outs, turn the high-speed dial out to soften the compression and lower the rear slightly.

 

 

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