Fat bike inner tube 20x4.0 with right valve

Size

Fat bike 20x4.0 inner tube: 20 inch outer diameter, 4 inches wide. This is the smallest of the three fat bike diameters in the catalogue, used on compact and folding electric bikes.

Fat bikes are defined by very wide tyres run at low pressure to absorb rough ground. The tube must therefore be designed for that air volume — a standard bicycle tube will not do.

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.

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. The large volume of a fat bike tube makes this check all the more useful.