Adjusting the suspension on your electric scooter: preload, rebound, and stiffness
Properly adjusting the suspension on an electric scooter involves first adapting it to your weight, then balancing the front and rear, and finally, if your shocks allow it, adjusting the speed at which they rebound. Most electric scooters come from the factory with a standard setting, designed for an average rider. If you are lighter or heavier, or if you ride fast, a few simple adjustments can significantly improve comfort and handling.
The essentials
- Identify your suspension type: coil and hydraulic shock absorber, coil only, or rubber cartridges.
- The preload setting adjusts how much the suspension compresses under your weight; it doesn't make the spring stiffer.
- If the initial preload is not sufficient, you will need a spring or cartridges with a different stiffness rating.
- On an adjustable shock absorber, the rebound setting controls the return speed: if it's too fast, the scooter will bounce; if it's too slow, it will bottom out on successive bumps.
- Change only one setting at a time and make a note of everything.
Types of suspensions:
| Type: | How does it work? | What can be adjusted |
|---|---|---|
| Spring and hydraulic shock absorber | The spring supports the weight; the damper oil slows down the movement | Pre-charge, sometimes referred to as rebound and compression |
| Single spring | The spring supports and absorbs, without braking the movement | Pre-charge, spring stiffness |
| Rubber (elastomer) cartridges | A rubber block compresses; it provides some cushioning on its own | Cartridge hardness, when changing it |
Several scooters, including some Dualtron models, use rubber cartridges that are available in various levels of firmness. Other models feature adjustable hydraulic shock absorbers, similar to those found on mountain bikes or motorcycles. Your scooter's manual will specify what adjustments are possible and how to make them.
Step 1: Adjust the suspension preload to match your weight
Static sag, often referred to as "sag," is the amount of suspension travel used when you mount the scooter, without moving. It's a fundamental setting because it positions the suspension in the optimal operating range:
- Excessive travel: The suspension bottoms out (reaches its maximum compression) on impacts, reducing ground clearance
- Not enough: the suspension doesn't compress much, it doesn't follow the contours of the road, and the tire loses contact.
To measure this, you need a reference point and a measuring tape: measure a reference distance on the scooter's suspension with the scooter empty, and then with you on it in your riding position (fully equipped, including your bag, with the help of someone). The difference, expressed as a percentage of the total suspension travel, gives you the amount of compression. The target value depends on the suspension and its intended use; the scooter or shock absorber manufacturer will specify this.
It is adjusted using the preload, often a threaded ring that compresses the spring to varying degrees when at rest. More preload results in less compression. If you reach the end of the adjustment range and still haven't achieved the desired result, the spring or cartridge may not have the correct stiffness for your weight, and you may need to replace it.
Step 2: Balancing the front and rear
A scooter that dives excessively at the front compared to the rear during braking becomes unstable in steering; the opposite makes it heavy and difficult to maneuver in turns. Aim for a balanced behavior: when encountering a series of bumps, the scooter should compress and return to a level position, without pitching forward or rearing up. On models with cartridge forks, it's common to use different stiffness settings at the front and rear to achieve this balance.
Step 3: Rebound and Compression
These settings are only available on adjustable hydraulic shock absorbers. They control the flow of oil within the shock absorber.
- Rebound damping controls the speed at which the suspension returns to its original position after a bump. If it's too loose, the scooter bounces like a ball and the tire loses traction; if it's too tight, the suspension doesn't have enough time to recover between bumps and ends up being compressed.
- Compression, when available, adjusts the resistance to compression. A tighter setting will cause the machine to compress less during braking, but will transmit more of the impacts.
Start with the original settings, adjust one or two clicks, run the same course, and compare the results. For track riding, these settings are part of a broader optimization process, which we discuss in our guide on the geometry of a track scooter.
Maintaining the suspension system
A perfect setup is useless on worn-out suspension components:
- Play in the joints: Arms, axles, and bearings wear out; a clicking sound during braking may originate from these components rather than the steering column. Refer to our guide on steering column play to differentiate.
- Leaking shock absorber: A trace of oil on the shaft indicates that the seals need to be replaced.
- Compressed Cartridges: The rubber ages, hardens, or cracks; it needs to be replaced.
- Fasteners: The suspension axles are controlled at the same rate as the rest of the machine, with the torque specified by the manufacturer.
Certain original parts wear out faster than others. Our Miniwalker suspension bars retain the original dimensions but are manufactured with a more robust design, restoring the suspension's performance and eliminating any play. For Dualtron Thunder, Achilleus, and Victor models, our CNC machined arms, made from solid stock and the same length as the original Thunder arms, provide increased rigidity and caliper mounting support on both sides.
Workshop tip
Before making any adjustments, check the tire pressure: on an electric scooter, the tires play a role in the suspension, and improperly inflated tires will distort all the feedback. Next, note the original settings (number of preload turns, number of rebound clicks): you can always revert to the starting point.
Frequently Asked Questions
Does increasing the pre-charge make the suspension stiffer?
Not really: the spring's stiffness doesn't change. The preload adjusts the height at which the suspension operates. If it's still too soft for your weight, you need a stiffer spring.
Why does my scooter bounce after every bump?
The movement is not being sufficiently dampened: this could be due to excessive rebound on an adjustable shock absorber, a shock absorber that has lost its oil, or a suspension system that relies solely on springs without any damping.
Should the suspension be adjusted differently when carrying a passenger or a heavy load?
Adding extra preload increases the amount of compression. If your scooter is designed for it, you can increase the preload; otherwise, stick to the maximum preload specified by the manufacturer.
Are stiffer suspensions better for achieving higher speeds?
Not necessarily. Suspension that is too stiff can cause the tire to lose contact with the road on uneven surfaces, reducing grip. The correct suspension setting keeps the tire in contact with the ground.