You are here: Measuring & Setting Sag

Measuring & Setting Sag

To achieve the best performance from your FOX suspension product, the proper measuring and setting of sag is vitally important. As a starting point, set sag for your fork or rear shock to 25% of available travel.

NOTE: While 25% sag is more than adequate for most riders, you can experiment and vary your sag percentage some to better suit your riding style, or personal preferences of handling characteristics and feel. For example, if your style is more downhill/shuttle, you can increase your sag percentage a few points (which implies less air pressure) to add some plushness to your riding platform. If your style is more all-mountain/XC, you can decrease your sag percentage a few points (which implies more air pressure), to firm up your suspension platform.

FOX suspension products typically have an o-ring on the shock body or fork upper tube, but if there is no o-ring, you can use a zip tie. Be sure to turn off Propedal or lockout on the shock or fork, as applicable.
Make sure that you are on a level surface, holding onto a single brake only.
Dressed to ride (including filled hydration bag, if you use one), position your bike next to a wall or table to support yourself. Mount your bicycle and bounce lightly, to compress both front and rear suspension slightly (this will help free up any friction caused by sticky new suspension pivots or slack head tube angles).
Assume a normal riding position for 15-30 seconds, letting the suspension fully settle. While in your normal riding position and without bouncing, reach down and slide the o-ring/zip tie into the scraper lip of your rear shock air sleeve, or the dust wipers of your fork or both, if your bike has full suspension.
This next step is critical for getting an accurate sag measurement: dismount your bike without bouncing, to avoid moving the o-rings/zip ties.
Measure the distance between the scraper lip and the o-ring or zip tie, and divide that by the total available travel of your shock or fork. For an example, your target sag percentage is 25% and your rear shock available travel is two inches (~50 mm); your target sag setting will be ½ inch (~12.5 mm), 25% of available travel (12.5 ÷ 50 = 0.25). Add or release air in 5 PSI (0.35 bar) increments with the FOX Racing Shox HP pump, and repeat steps one through six until your measured sag equals 25% of total available travel.

NOTE: For the best TALAS performance, always set sag in the long travel position. Sag and spring rate will automatically readjust when you change to different travel settings.

TIP: If your bike has full suspension, make sure your sag percentage setting is the same for both fork and rear shock for best overall performance.