Eclipse Performance BMX Race Tube — 20" × 30/47 mm SHOP and fast-rolling tyres from 25

and fast-rolling tyres from 25 to 45 mm on 700C wheels

give it a small amount of air to seat the tube without folds or twists

A spare 32" butyl tube is a brick

Ball valve adapter

Holds pressure at race PSI

Eclipse Performance BMX Race Tube — 20" × 30/47 mm SHOP and fast-rolling tyres from 2535 grams. That's what a standard butyl BMX tube weighs in grams after you subtract the 65 g you saved switching to this. For a racing class where a gate reaction of 0. 1 seconds separates the podium from the pack, rotational weight at the wheel is one of the few legal gains left on the table. Why it works 35 g. The entire tube. A typical butyl equivalent in this size runs 100 g or more. That's 65 g of rotational mass removed from each wheel