E-MTB Suspension Service: How Often to Service Your Fork and Shock

Suspension is the easiest service to forget, because nothing on the bike tells you it's due. The makers count hours. Fox lists a lower-leg oil change for its air forks every 100 hours or once a year, and RockShox starts its service chart with a lower leg service at 50 hours. Those are figures for normal riding. An e-MTB is heavier, gets you back to the top quicker, and through a wet winter it spends a lot of time in exactly the conditions Fox says need more frequent servicing. So treat the maker's figure as the longest you'd leave it, not the target.

I've ridden an e-MTB in the Forest of Dean since 2018. Here's how the intervals work, what the two kinds of service are, and how to tell when yours is due right now.

How often should you service an e-MTB fork and shock?

Here's what Fox and RockShox publish, with the Plus1 Garage's starting estimates for an e-bike underneath.

	Fork	Rear shock
Fox (air forks and shocks)	Lower-leg oil change and FLOAT air-spring fluid every 100 hours or once a year	Air sleeve maintenance every 30 hours; fluid service every 100 hours or once a year
RockShox	Lower leg service at 50 hours; damper and spring service at 100 or 200 hours, depending on model and year	Air can service has its own line on the chart; full overhaul every 100 to 200 hours, by model
E-bike starting estimate	Lowers at 340 miles or 6 months; full service at 850 miles or 12 months	Air can at 340 miles; full service at 850 miles or 12 months

A few notes on reading it.

• Fox. The Fox service interval table covers its air forks (32, 36, F-Series, FLOAT and TALAS), and the 100-hour service is the lower-leg oil change plus fresh fluid in the FLOAT air chamber. On the shock it splits the quick air sleeve job from the full fluid service, and that 100-hour service is work for Fox or an authorised service centre.
• RockShox. SRAM's RockShox service interval chart runs in steps of 50, 100, 200, 400 and 600 hours, plus a yearly line, and which step your fork's damper and spring service falls on depends on the model and year. The shock overhaul figure comes from a bike shop's summary of RockShox's advice, so look up your own model on the chart.
• The e-bike row is built from those maker intervals, but in miles rather than hours, because miles are what an e-bike display records. Each hour figure has a mileage alongside it (50 hours sits with 400 miles), and for an e-bike the suspension life is multiplied by 0.85, so a lowers service that starts at 400 miles on a normal bike starts at 340 on an e-bike. They're best guesses you can correct, not maker figures.

What's the difference between a lowers service and a full service?

A lowers service is the smaller, more frequent job. The lower legs come off the fork, the old oil and muck come out, and it goes back together with fresh oil. RockShox calls it a lower leg service; Fox's version is the lower-leg oil change.

A full service goes further, into the damper and the air spring. RockShox calls it damper and spring service, and it comes round at 100 or 200 hours depending on the fork. The rear shock has the same split: a quick air can or air sleeve service at the short interval, and a full fluid service or overhaul at the long one.

If you're handy and have the maker's service manual, a lowers service is a job you can learn at home. Damper work is best left to a suspension specialist or an authorised service centre.

Signs your fork or shock needs a service now

The hours are a guide. These mean it's due now, whatever the count says:

• Dry legs. Stanchions that look dry rather than slick.
• An oil ring after a ride. A ring of oil left on the stanchions when you get back.
• A knock. A clunk from the front end over roots, or when you hold the front brake and rock the bike.
• Oil on the shock, or the same sort of knock from the back of the bike.

A knock isn't always suspension. A loose headset can feel just like a fork knock, so check that too (see below). And a knock from the bottom of the bike may be the motor. Play in the cranks, grinding or knocking under load, or water or rust at the motor seals all mean booking the drive system in with your dealer. Motor bolts are dealer work, so don't go at them yourself.

Why e-bikes are harder on suspension

An e-MTB carries a motor and a battery, and the scales show it. The Avinox bikes listed by E-MOUNTAINBIKE Magazine weigh between 21.4 kg and 24.2 kg in the sizes quoted (my Avinox bike guide has the list), and an Avinox drive unit on its own weighs between about 2.52 kg and 2.65 kg, depending on the model. Every landing puts that weight through the fork and shock, which is why the e-bike figures in the table are shorter.

The other thing is how much descending you fit in. At the Forest of Dean Cycle Centre, more and more riders self-shuttle the downhill tracks on e-bikes, and with about 110 m of drop a perfect day is about a dozen runs. An hour of it is mostly descending, which asks a lot more of a fork than an hour of steady trail riding. My downhill and uplift guide has the rest of that story.

Wet, muddy and winter riding: service sooner

Fox is clear about this. If you often ride in extreme conditions, and it names wet and muddy riding, downhill racing and winter riding, service more often than its table says. That's a Forest of Dean winter in one sentence. The ground here is loam and clay, it's wet for months, and plenty of it ends up on your stanchions and seals.

What I'd do through the winter:

• Wipe the stanchions and seals with a soft cloth after every muddy ride.
• Wash the shock the way Fox says: mild soap and water only, then wipe it dry with a soft towel.
• Never point a pressure washer at the seals, the pivots or anything else on an e-bike. My guide to cleaning an e-bike explains why.
• Bring the lowers service forward rather than waiting for the hours, and look for the signs above every time the bike's clean.

Pivots, headset and dropper: the checks people forget

Suspension isn't only the fork and shock. The frame pivots, the headset and the dropper post all wear, and an e-bike's weight speeds up the first two.

The Garage starts pivot bearing checks at 800 miles or six months, the headset at 800 miles or 12 months, and a dropper service at 800 miles or 12 months. On an e-bike it trims the pivots to 80% (640 miles) and the headset to 85% (680 miles). The dropper gets no e-bike adjustment.

Two quick checks you can do anywhere:

• Headset. Hold the front brake on, rest your other hand around the top of the headset, and rock the bike forward and back. A clunk you can feel there usually points to the headset rather than the fork.
• Pivots. Lift the back of the bike and push the rear wheel side to side. Any play or knocking is worth a proper look at the pivot bearings (and the rear hub).

Keeping track of suspension service

The hard part of suspension isn't the service. It's remembering when you last had one. Hours are hard to count, and a fork doesn't come with a warning light.

That's what the free Plus1 Garage is for. Add your bike from the list, which fills in the fork and shock where it knows them, and type in the miles off your display now and then. Every part gets a bar (fine, coming up or due), and you get a reminder on the day something's due, and nothing else. If you've just had the fork done, or you've checked it and it's fine, you can set where it is in its life in one tap. It's a tracker with best-guess numbers, not a mechanic, but it does the remembering.

For the whole bike on one page, see the e-MTB maintenance schedule. Next in this series: e-bike battery care.