8.5x2 inner tube for 156 mm rim with straight valve

Size

8.5x2-6.1 inner tube: 8.5 inch tyre, 6.1 inch rim (156 mm). This size fits the Xiaomi M365, 1S, Essential, the Dualtron Mini and machines built on the same base. The rubber adapts to a range of widths around 2 inches.

The 8.5x2 comes in two rim diameters

This is the key point on this size. The 8.5x2 fits two different rims depending on the machine:

8.5x2-6.1 — 156 mm rim, Xiaomi and Dualtron Mini family
8.5x2-5.5 — 140 mm rim, Zero and Vsett family

A tube made for a 156 mm rim will be too large on a 140 mm one. Check the rim diameter before ordering: the 8.5x2 size alone is not enough.

Straight valve

The valve is perpendicular to the rim, with no bend. This is the simplest and most common fitment: it works whenever nothing obstructs access to the valve — no brake disc or motor facing it, and enough clearance under the mudguard.

On rims where access is restricted, an angled valve is required. Check the angle of the original tube before ordering: this is the leading cause of error on this product family.

Fitting

Sold individually. Inflate the tube slightly before inserting it into the tyre to avoid folds, and make sure it is not pinched between the bead and the rim before bringing it up to pressure.