What is “Setting Your Sag”?

Suspension advice from Solid Performance.

While there are many things you can do to improve your riding ability on your bike, setting sag is one of the most inexpensive and easiest ways to make drastic improvements to how the bike handles, delivering balance and stability while riding.

WHAT IS SAG?

Sag is what happens when the rear shock of your motorcycle compresses, lowering the rear end of the bike, making it (you guessed it) SAG!

Sag is of course affected by a riders weight, but also by the stiffness, softness or height of other suspension components. Sag settings are not one-fits-all; they can and should be measured, adjusted and tested according to riders’ preferred riding style and riding conditions. The right sag setting can improve handling, performance as well as comfort specific to each riders ride.

There are two different types of sag: rider (or race) sag and static (or free) sag:

Rider sag (race sag) is measured when the rider is sitting with all of his weight (gear included) on the bike. The sag is the amount that the suspension compresses under the rider while mounted in full riding gear. A proper sag setting allows the suspension to work most effectively and keep ideal weight balance in the chassis throughout the bike while it’s being ridden.

Setting race sag is one of the most important tech details that can affect your bike’s overall handling and performance. Ideally, a rider or racer should check this setting before each ride to insure it remains in the desired position.

Static sag (free sag) is the amount that the suspension compresses under the bike's own weight, and is not set-able until you have first set your rider sag. Once race sag is set, the amount the rear suspension sags under the weight of the sprung portion of the bike alone (without rider’s weight) is compared to the race sag, and set accordingly.

HOW SAG IS CHECKED AND ADJUSTED

Without going into too many specifics, the sag is basically checked using this process:

While the bike is on a stand, the distance between the rear axle to a set point on the rear fender is measured. Then, the rider (wearing full gear) can sit on the bike in riding position with both feet on the footpegs, bounce a bit to help the shock settle in its natural sag position, and then the distance from the rear axle to the same point on the rear fender is re-measured to see how much the rear sags.The difference in these measurements is the race sag. From there, adjustments can be made to the shock or other components.

Each bike has a recommended sag setting, typically between 97mm and 110mm. With testing, and with Solid Performance’s help, you can figure out which race sag is best for you.

TESTING SAG AND OTHER SUSPENSION SETTINGS

The best way to test out how settings are working for you is to RIDE! With Solid Performance on site at Over And Out, you can get your sag checked, ride some laps on terrain of your choosing (easier swoopy track, tight single track, or rocky river beds) and observe and record how the bike feels for you after each adjustment to either the sag or suspension clickers (if you have them.)

SOME IMPORTANT FACTS ABOUT SAG

Both the race sag and static sag must stay within their specified range to ensure optimum bike performance.
Race sag may be adjusted according to the riders’ specified range depending on track conditions and riding style.
When setting sag, the bike should be brought to normal racing weight (with correct fuel, transmission oil and coolant levels), and the shock should be cool to the touch, as heat build up directly affects the sag.
Less sag can improve turning ability at the cost of slightly reduced overall stability.
More sag can improve overall stability but may reduce turning performance slightly.
A spring that’s too firm does not allow the rear tire to hook up under acceleration and passes more of the bumps on to the rider.
A spring that’s too soft for your weight may force the spring to collect too much preload to achieve the proper race sag, making the rear end too high or even top-out when the rider dismounts. Weight transfer is incorrect and the rear end tops out under even light braking or on downhills.
A brand-new shock will need to be broken in for at least two hours of riding before being able to properly measure sag.