These inner tubes are made for fat tire bikes and e‑bikes that use 20x4, 20x3, 24x4, 26x3, or 26x4 tires. Simple, reliable replacements for stock tubes that have started leaking or gone flat.

Select your size and quantity (1 tube or 2 tubes) from the options above.

- 20x4 – fits most 20 x 4.0 fat tires  

- 20x3 – fits most 20 x 3.0 tires  

- 24x4 – fits most 24 x 4.0 fat tires  

- 26x3 – fits most 26 x 3.0 tires  

- 26x4 – fits most 26 x 4.0 fat tires  

Always check the size printed on your tire sidewall before ordering.

- Brand: POLAR BEAR  

- Part type: Inner tube  

- Valve type: Schrader (car style)  

- Material: Butyl rubber  

- Color: Black  

- Condition: New  

- Straightforward replacement tube for everyday riding  

- Works well on fat tire bikes and many e‑bikes that use these sizes  

- Standard Schrader valve – easy to inflate with most bike pumps or at gas stations  

- These tubes are sized to match the listed tire sizes (for example, 20x4 tube for a 20x4 tire).    

- If you’re not sure whether this will fit your tire, check the markings on your tire or send a message before buying.

- Ships from California (USA)  

- Packed securely to avoid damage in transit