Electric scooter rim: whether it's cast iron or CNC-machined aluminum makes a real difference
An electric scooter rim can be manufactured in two main ways: by being cast in a mold (foundry process) or by being machined from a block of aluminum using a CNC machine. Most original rims are cast, which is suitable for normal use. A machined rim offers a more consistent material, more precise dimensions, and often, a design optimized for performance. However, the most significant difference that impacts daily use lies elsewhere: knowing whether the rim can be split in half and whether it is designed for tubeless tires.
The essentials
- Casting: Aluminum is poured into a mold; this method is cost-effective, but the resulting material may contain small bubbles (porosity).
- CNC Machining: The rim is machined from a solid block; this results in a homogeneous material, precise dimensions, and a more expensive manufacturing process.
- A split rim, consisting of two parts, makes changing the tire simple, even with a rigid motorcycle tire.
- A tubeless rim must be perfectly airtight; this is where the quality of its construction becomes evident.
- A cracked, warped, or deformed rim caused by an impact must be replaced; it cannot be repaired.
The cast aluminum rim
In a foundry, molten aluminum is poured or injected into a mold shaped like the rim. This process allows for the production of large quantities at a low cost, which is why it is used in most mass-produced scooters.
Its limitations stem from the material: when cooling, the metal can trap small gas bubbles or exhibit less dense areas. This isn't necessarily a defect, and a well-designed cast rim generally performs its function effectively. However, to maintain the same level of strength, the manufacturer often needs to incorporate more material, which increases the weight. Furthermore, in a tubeless rim, poorly positioned porosity can cause a slow leak, which can be difficult to detect.
CNC-machined rim
A machined rim starts as a solid block of aluminum, which the machine carves out to its final shape with great precision. The material is uniform throughout the entire piece, without the variations typically found in a cast part.
- Precision: The rim is perfectly round, and its bearing surfaces (the areas that contact the motor and the tire) are accurate. The tire centers better, and the wheel vibrates less.
- Durability/Robustness: We can place the material exactly where it's needed for optimal strength.
- Sealing: The absence of porosity and precise surfaces are advantageous for tubeless systems.
- Cost: A significant amount of material is removed, and the machining time is long; a machined rim costs more than a cast rim.
Monoblock or half-rim
A one-piece rim is a single piece of metal. To mount a tire on it, you need to pass the tire's beads (its reinforced edges) over the rim's edge, using tire levers. This is feasible with the original, flexible tires. However, with a motorcycle tire that has a rigid casing, like the PMT tires often used on high-speed scooters, it becomes a real challenge.
A half-rim consists of two halves bolted together. You mount the tire, close it, and tighten it: changing a tire takes only a few minutes, without any special tools. This is the design we chose for our Rage Mechanics CNC aluminum rim: tubeless, anodized black, 6.5 inches in diameter, it opens in two halves to accommodate PMT tires from 90, 100, or 110 mm wide (or a CST 90) on Weped models and on our XHS and XHT motors. Our guide on how to change a scooter tire details the two mounting methods.
Our rims, and for which machines?
| Rim | Why? | Specific Features: |
|---|---|---|
| Rage Mechanics CNC aluminum rim | Weped SSR, SST, SSGT, FS, GTS, GTR; motors: XHS75, XHT75, XHS80, XHT80, XHS90; Lonnyo motors | Machined, tubeless, half-rim, standard 6.5-inch tires |
| Original-style Weped rim | Weped and XHS75 / XHT75 motors | Machined, tubeless, half-rim; maintains the original Weped format and tire sizes |
| Dualtron Thunder Rim | Dualtron Thunder, with original motors | Tubeless tire repair, or replacement of a damaged or deformed rim |
On Weped SST and GTS/SSGT models, the CNC aluminum rim requires a minor modification that takes just a few minutes. Please specify your model when ordering. The rims can optionally be painted with an epoxy coating by a professional, in eight different colors. Our guide on epoxy painting for scooter parts explains the benefits of epoxy coating compared to anodizing.
When is it necessary to replace a rim?
- Cracks, even small ones, especially around the screw holes or the rim's edge: the rim should be replaced immediately.
- Bent or crushed rim after hitting a curb: the tire no longer sits correctly and may leak or come off.
- Wheel wobble/instability: The wheel is no longer rotating smoothly, which is felt as vibrations at a constant speed.
- Repeated tubeless tire leaks without any punctures: this could be due to a damaged bead seat on the rim or porosity in the rim.
- `Tire change: Switching to wider tires or motorcycle tires may require a different rim. `
An aluminum rim cannot be straightened or welded for road use: the heated or bent metal loses its strength.
Workshop tip
With each tire change, carefully inspect the bare rim in good lighting, especially the edge and the area around the valve. This is the only time you can truly see a developing crack. On a half-rim, tighten the rim bolts in a criss-cross pattern, gradually, to the torque specified by the manufacturer: uneven tightening is enough to cause a leak in a tubeless setup.
Frequently Asked Questions
Is a machined rim always lighter?
Not necessarily: it can be designed for rigidity rather than for weight. Its main advantage is the consistency of the material and the precision of the dimensions.
Can you install a tubeless tire on any rim?
No: the rim must be airtight and designed for this purpose. Our guide choisir un pneu de trottinette compares tubeless and pneumatic tires.
Do you need a separate rim for each motor?
Yes, there is one rim per wheel. On our XHS and XHT motors, the CNC rim can be selected directly as an option on the motor's product page.
Can a bent rim be straightened?
We don't do that: aluminum that is bent and then straightened loses its strength, and the rim can break later. It should be replaced.