Bicycle Inner Tube FISCHER Dunlop Valve 20" (50-80 cm) ETRTO compatible

The FISCHER Bicycle Inner Tube with a Dunlop (Woods) valve is designed for 20" wheels and indicated for tire circumferences of approximately 50–80 cm. Compatible with standard ETRTO tire dimensions that match this size range, the tube serves as a practical replacement for puncture repairs and scheduled maintenance. Constructed for common urban and recreational bicycle use, it provides reliable airtight performance and straightforward installation on compatible rims.

Advantages

This inner tube features a Dunlop valve that is simple to inflate with hand pumps and many floor pumps equipped with the appropriate adapter. The tube is manufactured to common quality standards for single-wall butyl inner tubes, offering good air retention and resistance to gradual leakage. Its 20" size and 50–80 cm circumference indication make it suitable for a range of small-wheel bicycles, allowing an easy, like-for-like replacement without modifying the wheel or tire. The material and valve placement support standard repair procedures and help minimize installation time.

Suitable for

• 20" children's and folding bicycles with tires matching the stated ETRTO dimensions
• Small commuter or urban bikes that use Dunlop (Woods) valves
• Spare tube for roadside repairs and routine maintenance

Key specifications

• Wheel diameter: 20 inches
• Tire circumference indication: approximately 50–80 cm
• Valve type: Dunlop (Woods) valve
• Valve length: standard length suitable for typical 20" rims
• Material: butyl rubber (standard bicycle inner tube compound)

How to use

Before installation, check that the tire sidewall lists ETRTO dimensions compatible with a 20" inner tube in the 50–80 cm circumference range. Partially inflate the tube to give it shape, then insert it into the tire on one side of the rim. Work the tire bead back onto the rim, making sure the tube is not pinched between rim and bead. Fully inflate to the tire's recommended pressure as printed on the tire sidewall, and verify that the valve sits straight and the bead is seated evenly around the rim. After inflating, perform a visual and manual check for proper seating and air retention.

Usage recommendations

Use a correctly sized pump head or adapter for Dunlop valves to ensure a secure connection during inflation. When replacing an inner tube, inspect the tire and rim strip for sharp objects or damage to reduce the chance of repeat punctures. Maintain recommended tire pressure and periodically check for slow leaks to extend tube life.