Inner Tube FISCHER 20 inch (50.80 cm) with Auto (Schrader) Valve, model 85112

FISCHER 20 inch (50.80 cm) inner tube with Auto (Schrader) valve is a spare bicycle tube intended for wheels with a 20" (50.80 mm ETRTO) tire diameter. Designed to replace a punctured or aged tube, this model fits rims and tires compatible with Schrader valves and standard 20" wheel sizes. The construction focuses on airtight sealing and straightforward installation to restore rideability quickly.

Advantages

The tube is made for compatibility with common pumps and service stations that accept Schrader valves, enabling easy inflation without adapters. Its standard 20" sizing ensures broad fit across many adult and youth bikes, making it useful for both home repairs and workshop stocking. The design prioritizes reliable air retention and uncomplicated mounting to the rim and tire.

Suitable for

• Replacement of punctured or worn inner tubes on 20" wheels
• Spare tube for commuting and recreational bicycles with Schrader valves
• Workshop inventory for basic maintenance and quick repairs
• Use on bicycles for youth and adults where 50.80 mm (ETRTO) tires are specified

Key specifications

• Tube diameter: 20 inch (50.80 cm / 50.80 mm ETRTO)
• Valve type: Auto (Schrader) valve
• Compatibility: Standard 20" bicycle rims and tires designed for Schrader valves
• Material: rubber-based inner tube suitable for typical bicycle use
• Intended use: replacement/spare inner tube for routine maintenance and repair

How to use

Remove the wheel from the bicycle and deflate the tire completely before unseating one side of the tire bead. Extract the damaged tube and inspect the inside of the tire and rim strip for debris, sharp objects, or rough edges. Lightly inflate the replacement tube to give it shape, then insert the valve through the rim hole and tuck the tube evenly into the tire. Reseat the tire bead carefully to avoid pinching the tube, then inflate to the manufacturer-recommended pressure for the tire. Spin the wheel and check that the tire sits evenly on the rim and that the valve is secure before reinstalling the wheel on the bicycle.

Recommendations

Store the inner tube in a cool, dry place away from direct sunlight and sharp objects. When inflating, use the recommended tire pressure printed on the tire sidewall and avoid overinflation. Inspect tires and rim strips regularly to reduce the risk of repeated punctures. Carry a spare tube and a suitable pump when riding to enable quick roadside repairs.