R 18 Roctane tires

The OE tire sizes for the BMW R 18 Roctane (2023–present) are 120/70B21 front / 180/55B18 rear. Below are tires in these sizes, compared across brands. OE rim widths are F3.50 / R5.50 (from official specs; used for the rim-width check). OE sizes can differ by model year and market — the sidewall of your own bike is the sure reference. This is a Japanese-market lineup; the sizes themselves are international.

→ Open this bike in the chart (filter and sort there)

Tires that cover front and rear (5 models)

Front + rear set: 5 models can cover both ends (matching sizes in bold, based on F=120/70B21 / R=180/55B18). Shop links search on the model name alone.

Front 120/70B21 options (9 total, 5 of them listed in the set section above)

Size 120/70-21: 9 exact, 0 in the same group. Shop links carry each tire’s own matching size.

Rear 180/55B18 options (9 total, 5 of them listed in the set section above)

Size 180/55-18: 9 exact, 0 in the same group. Shop links carry each tire’s own matching size.

See also

• All BMW models (OE sizes)

How to read this

• The 1–5 ratings are our own estimates. Not manufacturer figures, not measurements.
• Within one model, character and street legality both change with the size and the spec. Confirm with the manufacturer or a dealer before you buy.
• Shop links go to search results rather than product pages. Other sizes and older models will be mixed in.
• “Narrower” means one or two steps below the OE size. The “rim width OK” badge means the tire maker's published rim widths line up with the OE rim width; no badge means unconfirmed.
• Competition tires may not be used on public roads.