21 Inch inner tubes in standard, heavy duty and ultra heavy duty, from IRC, Vee Rubber and more. A 21 inch tube is the front tube on every full size dirt bike, from the YZ125 and KTM 125 SX up to the 450s and the enduro and adventure bikes.
Common sizes on this page: 80/100-21 and 90/90-21. The tube size is the tyre size: read it off the sidewall and match the last number (the rim) and the width range on the tube.
Heavy duty tubes are 3 to 4mm thick and shrug off pinch flats on rocks and square edges; standard tubes are lighter and fine for motocross. Members pay the member price on every product in the store and get free standard shipping on orders over $10. Membership is $5 for the first month.
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Read the size off the tyre sidewall, for example 80/100-21. The last number is the rim size and must match exactly; the width range on the tube (80/100 or 90/90) just has to cover the tyre. 80/100-21 and 90/90-21 are the usual sizes here.
Heavy duty (3mm or more) for enduro, trail and rocks, where a pinch flat ends the day. Standard for motocross, where weight matters and the track is soft. Ultra heavy duty (4mm) for desert and hard enduro.
Not for a tube change. Check the rim tape covers every spoke nipple and the rim lock nut is tight; a loose rim lock is the usual reason a new tube fails straight away.
Not sure what fits? Set your bike at the top of the store and every list narrows to parts with confirmed fitment, or message us with your model and year.
