OHLINS ULTIMATE TUNING

OHLINS SNOWMOBILE
TRAIL & SNOWCROSS SHOCKS

ULTIMATE TUNING.

Improving your suspension does more for overall performance than increasing your engine's horsepower. You will feel the difference in the first corner!
    With a real world-class suspension you get better traction and handling. You ride with precision, thus more safely and as a plus… in comfort.
    Just ask any of our many snowmobile champions who won their titles on Öhlins shock absorbers. We guarantee they will agree. Good traction and handling are more important than extra horsepower that can only be used when you are aimed "straight ahead"!
    All our tests have shown that fitting Öhlins shock absorbers will improve handling but for the ultimate results you have to change "all around".
The reason for this is quite simple. For the ultimate in suspension improvements, the front and rear end of your snowmobile must match!

Start from the rear
The suspension on your snowmobile can be divided in to three parts: Front, centre and the rear suspension. If you do not want to change all shock absorbers at the same time, you shall start from the rear! First change the rear shock, than the centre and, for the ultimate result, the ski shocks at the front.
    When changing suspension components it is essential that you do not alter your snowmobile's suspension geometry. This applies particularly to your snowmobile's loaded ride height (ride height with rider on the snowmobile) front and rear. The ride height affects the weight distribution and the weight distribution affects both the steering and the traction.
    A high rear suspension will give heavy steering and bad traction. A high centre suspension will give the opposite result. And a high front will make the steering very sensitive, see also "Your own set up".

It is wise to check
All Öhlins shock absorbers are set up for normal cross-country riding with your snowmobile, as supplied by the manufacturer, ridden by a rider of average weight carrying light luggage or a passenger.
    Even if your snowmobile has no extra equipment it is wise to check the ride height after you have fitted your new shock absorbers.
To optimize your suspension it is essential that you have the correct ride height and that springs that suits your weight are used.
    Also remember that all of our test riders always test on brand-new snowmobiles. If your snowmobile is a couple of years old, it is wise to check that the shocks you do not change are still up to their original standard.

Winning concept
All Öhlins shock absorbers are based on Öhlins successful application of the "de Carbon" concept. The de Carbon concept means that the damping oil is placed under pressure by gas and separated from the gas by a floating piston.
    This concept has many advantages. It prevents the chance of cavitation, which happens when the oil can not move fast enough and becomes hard as a rock (compare with an unsuccessful dive into water). It offers better cooling, especially if the shock absorber has an external reservoir (the external reservoir is in fact an extension of the shock absorber and more oil, larger cooling areas improve performance and durability). Gives more consistent damping, regardless of the shock absorber's working temperature. And it makes the shock absorber last longer.
    But there is one exception. Öhlins Type 36E is an emulsion type of shock absorbers (oil and gas mixed in the shock absorber), see "Two concepts three types".

Not guesswork
All Öhlins snowmobile shock absorbers also have a new patented ice scraper on the piston shaft preventing ice from damaging the seals and moisture from entering the shock absorber.
    Öhlins manufactures more than 100 different shock absorber models, each model tailor-made for one specific snowmobile. Total length, travel, spring force and damping forces are carefully calibrated during testing riding cross-country and at race speeds on snow-cross tracks.
    The settings are consequently the results of extensive testing with your snowmobile and not guesswork!
    All Öhlins shock absorbers have, with a few exceptions, one or several adjusters. The minimum is adjustable spring and the maximum number of adjusters you will find on the top-of-the-line model, Öhlins 46PRC. The 46PRC feature a double-acting rebound/compression damping adjuster in the piston shaft and an independent compression damping adjuster in the external reservoir.

Your own set-up
You can fine-tune the shock absorbers with the adjusters. You optimize them for your weight, your riding style and the riding conditions.
    You compensate for extra load or a passenger with the spring adjuster. This means that you keep the balance that your snowmobile was designed with.
    Except for the suspension, spring preload also affects steering and traction. If the shock absorbers bottom when you are riding with a heavy load in rough conditions, the trick is to increase the spring preload only on the rear shock absorber which will result in no bottoming and a good steering response
    If your snowmobile has a limiter strap or a similar adjuster you can easily set it up for different kinds of snow conditions.
    A short limiter strap will increase ski pressure resulting in better steering response on hard snow.
    If you shorten the limiter strap a lot, you have to decrease spring preload on the centre shock. Otherwise spring preload will increase and the ride will be less comfortable.
    A long limiter strap will decrease ski pressure and increase traction for better handling in deep snow and on ice. And, you might loose steering response completely if the strap is too long!
    If your snowmobile is lacking an adjuster you can achieve the above results by decreasing or increasing spring preload on the centre shock.
    Less spring preload will increase ski pressure, more preload will decrease the pressure.
    We advice you to do the adjustments in small steps until you find the optimum setting. If you keep notes, it is easy to alter settings for different conditions.
    The double-acting rebound/compression damping adjuster in the piston shaft modifies the damping at a ratio of approximately 90% rebound, 10% compression. 10% effect on compression may seem like very little but feels like a lot. Remember that the spring absorbs most of the load transferred during a compression stroke. And you need the 90% on rebound to stop the spring from extending too fast during the rebound stroke!
    With the adjuster wheel on top of the external reservoir you add compression damping, without changing rebound damping.
    Too much compression damping will give you a harsh ride as your snowmobile "jumps" along the trail. With too much rebound damping it will have difficulties with several bumps in a row. The suspension will not extend fast enough between bumps, your snowmobile will ride lower and lower and eventually the suspension will bottom.
    Learning how to use the adjusters will take time but you will quickly appreciate them once you know the tricks. Even top riders sometimes need a specialist!
    Your own internal set-up is also possible. The Öhlins shock absorber is not a "disposable" shock absorber but one you can take apart, reshim, readjust and overhaul.

Precision is the difference
All Öhlins suspension products are designed to win races. The ones you can buy are exactly the same as the ones we sell to top teams and riders. The set-up might be different and by all means there are prototypes around. Progress can not be stopped!
    The Öhlins concept is not a secret, it is precision. Precision gives superior control of the damping oil and is the key to our success.
    Precision also results in quality, a quality you can both see and feel.
    For the ultimate in performance, Öhlins is the ultimate choice.

Compression Stroke

1. The oil flow in the shock absorber body and…

2. In the reservoir during a compression stroke.

Rebound Stroke

3. The oil flows into the reservoir and...

4. In the shock absorber body during a rebound stroke.

To show you what is happening in a Öhlins shock absorber when you are riding we have chosen a shock with a double-acting, rebound/compression damping adjuster in the piston shaft and an independent compression damping adjuster in the external reservoir.
    The principle illustrated here is the same for all types of Öhlins shock absorbers. Just disregard the adjusters that your shock absorber does not have and you can still understand how it works!

On a smooth trail
When you are riding on a smooth trail and the shock absorber is compressed slowly and only a small amount (low shaft speed and short stroke), the damping oil is forced through the double-acting rebound/compression adjuster in the piston shaft, fig 1 flow 3.
    The oil displaced by the piston shaft is forced through the independent compression damping adjuster out into the external reservoir, fig 2 flow 3.
    The floating piston in the reservoir is forced to move, compressing the gas behind it.
    When the shock absorber extends the gas pressure behind the floating piston will force the oil through a one-way valve, past the compression adjuster and back into the shock absorber body, fig 3 flow 1 and 2.
    The oil under the piston returns through the double-acting rebound/compression adjuster in the piston shaft, fig 4 flow 3.

Hitting a big bump
When you hit a big bump the shock absorber is compressed quickly and almost totally (high shaft speed and long stroke).
    The oil can not be forced " fast enough" through just the valve in the piston shaft. The pressure in the shock absorber increases and force open the shim stack (thin steel washers stacked as a pyramid) covering the compression orifices in the piston, fig 1 flow 2.
    Also, oil displaced by the piston shaft can not be forced " fast enough" through just the valve in the reservoir. The pressure increases and a shim stack, parallel to the valve, opens, fig 2 flow 1 and 2.
    The floating piston is forced to move compressing the gas.
When the shock absorber extends, the floating piston will force the oil through the one-way valve back into the shock absorber body, fig 3 flow 1 and 2.
    The pressure is still high in the shock absorber and the flow can not be forced through just the valve in the piston shaft. The shim stack covering the rebound orifices in the piston opens and the oil returns, fig 4 flow 1.

All are tailor made
By changing the number, diameter, and thickness of the shims in the stacks and by using different jets in the valves, your Öhlins shock absorber is tailor-made for your snowmobile. The set-ups are not guesswork but the results of true tests with a snowmobile exactly like yours!