Does an E-MTB need a special suspension fork?

EMTB Magazine: What does E-Optimised mean?

Chris Trojer: E-Optimised stands for Fox suspension forks that have been developed explicitly for the requirements of modern e-bikes. The system weight, i.e. rider and bike, is higher on an e-mountainbike than on a traditional MTB. The loads on the fork are therefore higher, and experience has also shown that e-MTBs have a higher mileage in a shorter time. In most cases, higher deceleration forces are required to brake the bike. Basically, it is therefore a matter of absorbing the higher number and strength of forces in a targeted manner and thus generating safe and balanced riding behaviour.

What exactly are the differences to "normal" Fox forks?

With E-Optimised, we primarily work with a reinforced fork chassis. The damping and suspension technology is basically identical to the normal Fox suspension forks, but is specifically adapted to the E-Optimised chassis. This chassis has a forged fork crown made of solid material. Normal forks have a milled fork crown to save weight. We also use a thicker-walled head tube and thicker-walled stanchions - two millimetres thicker in diameter.

Have you adjusted the damping?

We have a large number of "valve codes", i.e. tuning of the damping cartridge. This "software" in the damping cartridge is specifically adapted to the targeted rider profile, the suspension travel, the wheels used and the compression ratio of the air spring in order to generate the best possible riding behaviour. The set-ups that we have developed in the MTB enduro segment are also ideally suited to the requirements of e-bikes - both off-road and on-road.

Why do I need a special E-MTB suspension fork? The rider's weight also fluctuates...

The comparison with the rider's weight immediately springs to mind, of course, but is actually a somewhat misleading comparison: the person on top of the bike transfers the forces to the fork in a completely different way to the motor and battery - these are rigidly mounted in the frame of the bike. In addition, people can use their arms and legs to quickly and flexibly change their centre of gravity on the bike. The motor and battery cannot do this. In addition, the drive unit is mounted so low in the frame that its weight is all the more noticeable. This is because its moment of inertia pushes directly towards the front wheel, where the main deceleration occurs when braking. The fork is therefore subjected to considerably more stress at the point where all these forces come together: At the lower end of the head tube, exactly where our E-Optimised suspension forks are significantly reinforced. Basically, it's about the forces and their direction that are applied to e-bikes. These differ from "normal" MTBs.

At what intervals does the fork need to be serviced? Can I do this myself?

Our recommended service intervals for all Fox suspension forks are the same: a service should be carried out every 125 hours or once a year - whichever comes first. You can carry out all service work on our products yourself and, if carried out correctly, the warranty will always remain valid. All information is freely available on our website in the Help section. Tools, seals and oils are freely available and can be obtained via Fox Germany or a competent specialist dealer.

Laboratory values Fox 36

Ride review: Fox 36 Float E-Optimised

We were able to test the Fox 36 Float suspension fork on the Skull Trail on Lake Garda. As is typical for Fox, the fork responds very sensitively and absorbs even the smallest bumps. When the trail gets steeper, the 36 is high in its travel and does not sag. The fork literally inhales big bumps and provides a lot of security even at high speeds. The handling is very direct and the stiffness is significantly higher than that of a "normal" 36. The extra stiffness comes at the price of an additional weight of around 250 grams - but on an e-mountainbike this is not a significant factor.