Inner tube 8.5x2 valve 90x90°

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.

90x90° valve

The valve is angled at 90 degrees on both segments. This double bend brings the inflator head parallel to the rim, where a straight valve would be unreachable between the brake disc and the fork arm.

The angle is dictated by the rim and mudguard geometry. Check the one on 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.