Setting Rear Shock Sag the Right Way (and Why It Matters)
Sag is the single most important suspension setting on an electric dirt bike. Here is how to dial it in correctly.
Static sag is the amount the suspension compresses under just the bike's weight. Rider sag adds your body weight in full riding gear. Together, they tell you whether your spring rate is right.
Target ranges for FASTACE rear shocks on Sur-Ron / Talaria platforms: rider sag 28–33% of total stroke; static sag 5–10 mm. Outside these ranges, change the spring rate before touching damping clicks.
Procedure: 1) Bounce the bike to settle. 2) Push down to fully compress, then let it extend — measure rear axle to fender, this is your full extension. 3) Sit on the bike in normal riding position with gear on, repeat measurement. The difference is rider sag.
If you wind preload past four turns to hit target sag, the spring is too soft. Less than half a turn — too stiff. Order a stiffer / softer FASTACE replacement spring before chasing damping symptoms.