E-MTB suspension setup: SAG, pressure & tyres
An electric mountain bike rides differently from a classic MTB: it is heavier, the centre of gravity is lower and, thanks to the motor, speeds and loads are higher. That is why the suspension needs its own setup. Here is what matters.
What is different on an e-MTB?
- Weight: full-power e-MTBs with Bosch Performance Line CX, Shimano EP801, DJI Avinox or Giant SyncDrive usually weigh 22–26 kg. Light e-MTBs with TQ HPR50, Fazua Ride 60 or a Specialized SL motor weigh 17–20 kg.
- Centre of gravity: battery and motor sit low in the frame. The bike feels planted but puts more load on the suspension on landings.
- Speed: with motor assistance, climbs and berms are ridden faster. The forces on fork, shock, tyres and rims increase.
- Unsprung mass: robust tyres, inserts and strong wheels increase wheel weight, which affects damping.
SAG and air pressure on an e-MTB
The target SAG hardly differs from a normal trail or enduro bike: 20–25 % at the fork and 28–30 % at the shock are good starting values. Because the mass of the bike itself acts on the suspension, e-MTBs need a little more progression and often a few psi more pressure for the same SAG while riding. Many riders prefer the lower end of the SAG range on e-MTBs so the bike sits higher in its travel on steep climbs.
How to measure SAG is explained in our guide SAG setup. The right starting pressure for your model is calculated by the suspension calculator – it contains more than 750 e-MTB models from Specialized, Trek, Cube, Canyon, Orbea, Santa Cruz and many other brands.
Rebound and compression
Because of the higher mass, an e-MTB rebounds more sluggishly than a light bike at the same rebound setting. So start with the rebound about 1–2 clicks faster (more open) than on a comparable non-assisted bike and test on rough sections. On the compression side, a little more low-speed compression helps stop the rear from sagging too much when you pedal hard with motor assistance.
Air spring or coil spring?
Coil shocks such as the RockShox Super Deluxe Coil, FOX DHX or Öhlins TTX22m are popular on e-enduro bikes: they are very sensitive, barely heat up on long descents and cope well with the high weight. Air shocks are lighter and easier to adapt to rider weight. If the calculated air pressure is close to the maximum, a coil shock or a firmer spring is the better choice.
Volume spacers: e-MTBs often run 1–2 more spacers than normal bikes to prevent bottoming out on landings.
Tyres and wheels
On an e-MTB, the tyres carry the biggest load. We recommend:
- Robust casings: e.g. Maxxis DoubleDown, Schwalbe Super Gravity or Radial, Continental Enduro/Downhill, Michelin Racing Line.
- 2.5–2.6″ width for more volume and grip.
- Tubeless with an insert to protect the rim – a cracked rim is a common failure on e-MTBs.
- About 0.05–0.1 bar (0.7–1.5 psi) more pressure than the same rider on a normal MTB. You will find guideline values in the tyre pressure chart.
Motors and typical weight
| Motor class | Examples | Typical bike weight |
|---|---|---|
| Full power | Bosch Performance Line CX, Shimano EP801, DJI Avinox, Giant SyncDrive Pro, Specialized 2.2 | 22–26 kg |
| Mid power | Bosch Performance Line SX, Rocky Mountain Dyname | 19–22 kg |
| Light / SL | TQ HPR50, Fazua Ride 60, Specialized SL | 17–20 kg |
The closer a light e-MTB comes to the weight of a normal bike, the more its setup resembles that of a classic trail bike.
Maintaining an e-MTB
Because of the higher loads and more climbing, seals, bushings and bearings wear faster on an e-MTB. Stick to the lower end of the service intervals from FOX, RockShox and others, regularly check bearing play and bolts on the rear end and clean the stanchions after every ride. Important: remove the battery before cleaning and never use a pressure washer.