Suspension school · Tuning by Riding Style

Heavier and Lighter Riders

Setup at the edges of the chart: over 100kg and under 60kg

Suspension charts and factory damper tunes are built around a 75 to 85kg rider. On an eMTB the picture at the extremes is unusual: the bike's own 20 to 27kg is a bigger share of the total for a light rider, while a heavy rider plus a full-power bike can put more than 130kg of system mass through the components.

Over 100kg: Working Near the Limits

The first hard constraint is pressure. Air springs have published maxima, a Fox 38 tops out at 140psi, and a heavier rider working from an eMTB chart can land close to a fork's ceiling. Check the maximum in your fork and shock manual before pumping toward a number. If the chart asks for more than the spring allows, the answer is a different spring, not more air.

• Volume spacers: run more, a Fox 38 allows up to six at 160mm travel, five at 170mm and four at 180mm, and heavier riders usually sit a spacer or two above the stock fit
• Damping: firmer across the board, more spring force needs more rebound and compression control, expect to sit several clicks fewer from fully closed than the chart's midpoint
• Coil shocks: check spring availability first, stock ranges typically stop around 600 to 650 lb/in, and some frames at 30% sag need more than that for a 110kg rider
• Damper tune: if compression is fully closed and the bike still blows through its travel, the damper needs a firmer tune from a service centre, no external click fixes an under-damped stack

Casings and rims carry the same load. At over 130kg all-in, a reinforced rear casing is the minimum: Maxxis DoubleDown, Schwalbe Super Gravity, Specialized GRID Gravity or Continental Enduro, with the DH casings a sensible next step. Run 2 to 3psi over the chart, and fit a rear insert purely for rim protection.

Under 60kg: The Opposite Problem

Light riders fight the factory in the other direction. Pressures come out so low that seal friction becomes a real fraction of the spring force, dampers valved for an 80kg rider feel over-damped even fully open, and full travel becomes something that happens to other people.

• Volume spacers: remove them, running zero or one is normal and is often the single biggest improvement
• Rebound: near fully open is frequently correct at low pressures, it is not a setup mistake, it is where your spring rate lives
• Compression: start fully open and add only what you can actually feel
• Still harsh with everything open: a lighter damper tune from a tuning centre is the honest fix, and cheaper than living with a fork you cannot use
• Measure sag fastidiously, at 55kg a 3psi error moves sag much further than it does at 90kg

Tyres have a floor as well as a ceiling. Below roughly 18psi at the front and 20psi at the rear, even a light rider will feel the casing fold in corners and the rim start to ring on square edges. Lighter casings, Maxxis EXO or Schwalbe Super Trail, make more sense here than ever-lower pressures: they cost less grip than a folding sidewall, and the loads that destroy them under a 100kg rider mostly are not present.

Both Ends of the Scale

Verify with evidence rather than feel: the O-ring on the stanchion and shock shaft after a hard run you know well. A heavy rider wants to see around 90% of travel used on the biggest hit of the day without a harsh stop. A light rider should chase the same target from the other direction, and if the ring says 70% after your roughest local descent, the setup is still holding travel hostage, whatever the chart claimed.

And a small mercy for lighter riders: the eMTB's mass, sitting low and central, adds a planted quality that light riders on light bikes rarely feel. Set up properly, with the spacers out and the damping freed off, it is an advantage rather than a burden.