Springs decide how far your suspension moves and how hard it pushes back. Get the rate wrong and every clicker on the bike becomes a compromise between two bad options.
Stock springs are set up for a rider of roughly average weight riding at roughly average pace. If that is not you — and for most riders it is not — the bike is working against you from the first lap, and no amount of adjustment gets it back.
Spring rate is measured in kilograms per millimetre: how much weight it takes to compress the spring one millimetre. A 5.4 kg/mm shock spring needs 5.4 kg to move it 1 mm, 10.8 kg to move it 2 mm, and so on. Higher number, stiffer spring.
Every chart on this page — and every chart anywhere else — assumes geared weight. Boots, helmet, chest protector, knee braces, and goggles typically add 10 to 15 pounds. That is frequently enough to move you a full rate.
Stand on the scale in everything you ride in, helmet included. It feels ridiculous. It is also the single number the rest of this page depends on.
Starting points by geared rider weight, in kg/mm:
| Geared weight | Rear shock | Fork (each) |
|---|---|---|
| Under 130 lb | 4.6–4.8 | 0.42–0.44 |
| 130–144 lb | 4.8–5.0 | 0.44–0.46 |
| 145–159 lb | 5.0–5.2 | 0.46–0.47 |
| 160–174 lb | 5.2–5.4 | 0.47–0.48 |
| 175–189 lb | 5.4–5.6 | 0.48–0.50 |
| 190–204 lb | 5.6–5.8 | 0.50–0.52 |
| 205–219 lb | 5.8–6.0 | 0.52–0.54 |
| 220–234 lb | 6.0–6.2 | 0.54–0.56 |
| 235 lb and up | 6.2+ | 0.56+ |
These are starting points, and they are generic. Rates vary by model, by year, and especially by linkage design — two bikes with the same rider can genuinely want different numbers. Confirm against your own bike's spring chart before you spend money on springs.
Pace moves you within the range rather than to a different one:
This is why two riders of identical weight can correctly end up on different springs. Weight sets the range; pace picks the point in it.
A chart is a prediction. Static sag is a measurement of your actual bike with your actual body on it, and where the two disagree, the measurement wins.
The test: set race sag correctly first, then measure static sag.
| Static sag (race sag correct) | Verdict |
|---|---|
| Under 25 mm | Shock spring too soft — you're propping the bike up on preload |
| 25–30 mm | On the soft side; rideable, stiffer would be better |
| 30–40 mm | Rate is right for your weight |
| 40–45 mm | A touch stiff |
| Over 45 mm | Spring too stiff — harsh, won't settle in corners |
If sag says your spring is right and a chart says otherwise, believe the sag. The chart has never met your bike.
Enter your geared weight and your three sag measurements. MXDialed gives you the rate range for your weight and pace, then cross-checks it against what your bike is actually doing — and tells you which one to trust.
Open the spring-rate check →Free, no signup, works on a phone at the track.
The tell that separates a rate problem from a damping problem: a wrong rate is wrong everywhere. Damping problems are situational — bad in the whoops, fine elsewhere. If the bike is unhappy in every condition and clickers only move the problem around, look at the spring.
Change one end only and you have altered the bike's balance as well as its rate. A bike that was simply soft can come back soft at one end and mismatched at both, which is harder to diagnose than what you started with.
If budget forces a choice, the shock spring generally does more for how the bike handles — it drives rear traction, squat under power, and the ride height that sets your steering geometry. But treat that as triage, not a plan.
Before you buy springs, rule out worn oil. Fork oil past roughly 30 hours and shock oil past roughly 40 is contaminated and foaming, and it feels remarkably like a wrong spring rate. A service is a lot cheaper than a set of springs, and a surprising number of "my springs are wrong" bikes are just overdue.
Young riders change weight fast, and a 50 or 65 rider can outgrow a spring inside one season. The bike does not announce this — it just gradually stops working, and the rider assumes they have got worse.
Re-weigh a growing rider at the start of every season and again mid-season. It is the cheapest performance gain available on a kid's bike.
Set race sag correctly, then measure static sag. Under 25 mm means too soft. On track it shows up as squat under acceleration, bottoming on landings, and a bike that rides low and feels vague everywhere.
Yes — gear is usually 10–15 lb, and the bands on this chart are 15 lb wide. Skipping it is often the difference between the right spring and the next one down.
Only within a narrow range. Preload changes where the spring starts, not how stiff it is. Push it far enough to mask a wrong rate and static sag collapses, the shock starts its stroke in the wrong place, and the bike behaves badly everywhere. It is a stopgap, not a fix.
It changes where in the range you sit. Fast riders load suspension much harder and want the stiffer end or a step above; beginners and trail riders want the softer end.
Oil height changes the air spring deep in the stroke, so it adds bottoming resistance without making the top of the stroke harsh. It is the right tool when the fork is fine over chop but blows through on big hits — and the wrong tool when the fork is soft everywhere. That is a rate problem.