Reading your tyre

Off-road motorcycle sizes are usually written as width / aspect / rim on one sequential line. Example: 90/100-21 M/C 57R. 90 = nominal section width in millimetres; 100 = aspect ratio = 100% of that width; 21 = rim diameter in inches. On many Goldentyre sizes, M/C and the load/speed symbols (57R) follow immediately on the same shoulder line after the size — not stacked underneath. Match the size to your rim and the bike’s approved fitment list.

Where present, the figures after the size are indices, not a weight printed in kilograms. In the example 57R: 57 = load (weight) index — a design code for the tyre’s rated load capacity (see Load index table: 57 → 230 kg reference mass); R = speed index — a design code for the tyre’s rated speed capability (see Speed index table: R → 170 km/h). These indices are design references for the tyre — not a licence to overload. Adventure and road-legal dual-sport tyres often carry clearer load cues than pure Motocross knobbies. When in doubt, stay within the motorcycle manufacturer’s wheel and tyre specifications.

Arrows on the sidewall show intended rotation. Fit front and rear accordingly. Crossing direction on a driven rear can tear knobs and ruin carcass stability.

Soft, intermediate and hard compounds are chosen for soil type and temperature. Soft grips in mud and loam but wears faster on hardpack; hard lasts longer on rocky or dry terrain. Pick for the day you ride, not the brochure photo.

E-mark (for example E24) is ECE type-approval for street / on-road use; the number is the approval-country code. DOT is a Dept of Transportation compliance mark — it is not the production date. Week and year of production appear separately (shown here as XX/XX as a teaching placeholder).