Wheelchair 24 Inch Sizing in the CST C3E25 Scooter Tube

The CST C3E25 Scooter Tube is a 24 x 1 replacement built to the 25-540 ISO size, the 24 inch standard used on wheelchairs and many mobility scooters. That ISO number matters more than the 24 inch label on the box. A 24 inch BMX or kids bike wheel is usually 507 mm, and a 540 mm tube will not fit it, so read the number on your tire sidewall before you order. Wall thickness is 0.97 mm and the valve shaft is smooth.

A standard Schrader valve means any floor pump, hand pump, or gas station air hose will inflate it, with no adapter and no special pump head. That is exactly why Schrader turns up on mobility equipment, where the person topping off a tire should not need a specialty tool to do it. The tube is butyl, which holds air well and patches with an ordinary patch kit. If you are unsure which 24 inch size you are on, bring the wheel by the lab and we will read the sidewall with you.