Biketube’s new Butane Black performance series tubes use a 0.73mm butyl rubber wall which is thinner and lighter than the standard (0.9mm). Biketube claims the thinner material also helps with rolling resistance.
The most interesting feature, though, is the tube’s black aluminum valve stem with a removable valve core. Together, the thinner rubber and aluminum valve add up to a 20g weight savings per tube.
Offered in 48, 60, and 80mm valve lengths. Tubes fit 23-30mm tires. Pricing starts at $10.50 for the 48mm valve. Hopefully, these are actually an improvement. If I install one more tube and have it immediately fail where the valve stem is vulcanized to the tub I might start hurting things.