KTM Shock Sag Adjustment and Setup - Cycle News

KTM Shock Sag Adjustment and Settings
KTM Shock Sag Adjustment is a crucial step for proper bike setup. Each KTM is engineered to work best at a certain suspension balance. The spring in the shock is adjustable to ensure the bike can be set properly for your weight.

To start, make a mark with a marker on the rear fender. Newer KTM’s have SAG written on the fender marking a good spot for measurements. It’s important to always measure in the same location.

You can use a purpose-built motorcycle sag scale or a tape measure—anything to get accurate measurements. We prefer a sag scale because it’s easy to set to “zero” when the bike is elevated on a center stand—the first measurement in the sag-setting procedure.

Make sure the bike is fully off the ground on a center stand and zero out your sag scale or, if you’re using a tape measure, write down this first measurement so you can do some math later.

Next, remove the bike from the stand and have the rider, in full riding gear, sit on the bike in a neutral position. The rider can bounce a few times to settle the shock, or another person can push down on the rear of the bike a couple times to settle it into a position. Having someone balance the bike while the rider sits still for measurement is helpful.

Typical rider sag settings (the amount the rider squats the rear shock) are generally between 100mm and 110mm. Check what KTM recommends for your specific year and model and use that as where you should start.

Adjusting the sag
If the sag is out of the recommended spec, place the bike back on a center stand. Take a marker and make a mark on the adjustment ring on the shock so you can tell when you’ve made a full turn of adjustment. KTM uses a lock ring with a 4mm allen to hold the adjustment ring. Loosen this before trying to make adjustments.

If you need more sag, loosen the adjustment ring so the spring has less tension. If you need to reduce the amount of sag, tighten the spring tension by tightening the lock ring down. Sometimes, you can turn the spring and adjuster by hand. If it’s too difficult to move by hand, use a lever. Place a rag between the lever and the frame or shock reservoir (depending on which way you’re turning the lock ring) and turn the lock ring one step at a time.

A full turn of the lock ring is approximately 3mm of sag adjustment in either direction. Measure the sag with the rider again to confirm you’re within spec. If you are, tighten the lock ring. If not, continue to adjust the spring tension until you are. Then, tighten the lock ring. Don’t forget to tighten the lock ring!

There’s a possibility the stock rear shock spring is not the proper spring rate for the rider’s weight.

Free Sag
A great way to determine if the spring rate on the bike is right for the rider is by checking Free Sag. Free sag is the amount of sag (or how much the shock is compressing) without the weight of the rider.

To see if the spring is right first set the proper rider sag as described above and then check Free Sag by simply measuring with the bike level on the ground without a rider. Proper free sag varies between years, makes and models, but for KTM it is typically between 30mm and 45mm.

If free sag is outside the manufacturer’s recommended range, a different spring of a different spring rate is typically needed. If free sag is less than 30mm after rider sag is set properly, you likely need a stiffer shock spring. If free sag is more than 45mm, you likely need a softer spring to get the bike in-range.

Once your KTM Shock Sag Adjustment is dialed in with proper sag settings and the correct spring rate for a rider’s weight, it will work optimally, just like it was designed to.