550/650x17/18 Race Valved Inner Tube
These are the best tubes you can fit. Thick, correct dimension (other brand tubes with this size are too large) Butyl material and built to an unsurpassed quality. This tube has the metal valve stem which is nickel plated as they were in period.
Note that ALL other tubes available elsewhere today are listed to fit too many tyre sizes! Those marked with the 550x18 size are always too big, so quality issues aside, just don't fit them, whatever the brand name or salesmans advice you're given, because they are the wrong size! This is why we make Blockley tubes, to rectify what has been and is going on for too long. so for example, at Blockley for 19" tyres we make 19" tubes, which is how it should be . . .