8.5"x2" Pneumatic Scooter Tire (M365 size)

scooter– EUR

Origin

Inherited from the original Xiaomi Mi M365 — small enough to keep the scooter foldable and lightweight, large enough to handle typical urban pavement Originally Xiaomi + CST collaboration; now an open industry standard 8.5 inches was a compromise: smaller than bicycle tires (so the scooter is portable and lightweight), larger than the 6.5" hoverboard tires (so it handles cobblestone and curb edges without being thrown off). The 2" width was chosen for stability without excessive weight. Segway/Ninebot KickScooter (used 8" airless tires), various pedelec scooters with 10"+ tires 10" tubeless (Ninebot Max, Xiaomi Mi 4 Pro), 11" tubeless (Apollo, Mantis premium scooters)

The verdict

+Strengths

Universal cross-brand standard — same 8.5"x2" (50-134) fits the entire M365 clone ecosystem plus VSETT/Zero/Inokim 8.5" scooters, so spare parts are cheap and everywhere
Widest aftermarket variety of any scooter size — pneumatic, tubeless self-sealing, slime, solid, honeycomb, winter and off-road all available in one size
Schrader (car-tire) valve means any bicycle floor pump, electric pump or petrol-station compressor fills it
Pneumatic ride quality is the best entry-level option for absorbing cobblestone vibration in Baltic old towns

−Weaknesses

Pneumatic versions puncture readily on Baltic cobblestone and broken glass — typically 1-3 flats/year for a daily commuter
Rear (motor) wheel replacement is genuinely hard (8/10) — the hub motor casing must be split, easy to nick the cable or strip a screw
Solid airless variants are harsh enough on granite paving to cause wrist soreness and loosen scooter screws — strongly discouraged for cobblestone cities
Short lifespan vs larger sizes (1000-3000 km pneumatic vs 3000-6000 km on 10" tires) and pressure must be checked every ~2 weeks

Did you know

01The 8.5"x2" size existed for decades in industrial hand-cart and warehouse-trolley applications before Xiaomi adopted it for the M365 in 2017. Xiaomi did not invent the size — they just picked a stock industrial size that was already in mass production, which is one reason the M365 was cheap enough to disrupt the market.
02Because the size is now used by an estimated 15-20 million scooters worldwide, the aftermarket tire variety for 8.5"x2" is the widest of ANY scooter size. You can buy pneumatic, tubeless self-sealing, slime-filled, solid rubber, honeycomb solid, studded winter, off-road knobby, and even slick racing variants — all in the same physical size.
03CST CHO-AC-A4 (the OEM tubeless self-sealing variant from 2022 onward) contains a pre-installed sealant that seals punctures up to ~3mm automatically as you ride. The sealant is good for 12-18 months before drying out, after which it can be re-injected through the Schrader valve with a syringe.
04Solid-rubber 8.5" tires are famously uncomfortable on cobblestones. Tallinn and Riga old-town riders who switch from pneumatic to solid almost universally regret it within 50 km — the vibration is harsh enough to loosen scooter handlebar screws and can fatigue the deck welds over time on cheaper scooters.
05Replacing the rear tire on an M365-class scooter is genuinely difficult — the rear wheel is the motor, and you must split the motor casing to remove the tire. First-time DIY attempts often damage the motor cable or strip an internal screw. Most local scooter shops in Tallinn/Riga/Vilnius charge €20-30 labour and it is usually worth paying.
06The Schrader valve on 8.5" scooter tires is the same as a car-tire valve — meaning you can fill a flat scooter tire at any petrol station with a coin-operated air pump. This is one of the genuinely user-friendly aspects of the platform and a reason Schrader was chosen over Presta.
07Slime sealant (the green liquid sold for bicycle and lawnmower tires) works fine in 8.5" scooter tubes. About 60ml per tube provides good puncture self-sealing for ~12 months. Costs €5-8 per bottle, treats 2-3 scooter tubes. A common DIY upgrade over OEM dry tubes.
08On the M365 generation, the rear tire wears approximately three times faster than the front because all the propulsion AND most of the braking happen at the rear. Plan to replace rears 3x as often as fronts. Some commuters keep a spare rear tube taped under the deck for roadside repair.
09Xiaomi's choice to keep 8.5" on the Mi 4 base model (2024) — even after moving the Pro version to 10" — confirms the size has another decade of life in the entry-level commuter segment. Spare-part availability will remain excellent through at least 2030.

Who it’s for

Urban commuter on M365-class scooterDaily Tallinn / Riga / Vilnius commuter on mixed pavement and cobblestoneLight delivery rider (Wolt, Bolt Food on scooter)Student or budget rider on entry e-scooterWeekend recreational scooter user

8.5"x2" Pneumatic Scooter Tire (M365 size)

Origin

The verdict

Who it’s for

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