A Blockley tube marked 600/650x19. A superb quality rubber valve stemmed thick butyl inner tube for the 600 and 650 section 19" tyres. A great product, the best tube you can buy. This version of our tube has the rubber valve stem, but we also supply a metal stemmed version. Usually you will find that a tube marked up with a 600x19 size will also be the same tube they recommend for a 700x21 tyre! But at Blockley we make separate tubes for these other sizes, as it should be. Hopefully this will point out why we had to make tubes to go with our tyres as well . . .

We use these inner tubes in our Blockley 600x19 tyres (marked "550/600x19").

Remember if you have a tyre marked 550/600 it will be a 600x19, so this tube is suitable. 

And also note that for 18" tyres we make a different tube size. Other brands tend to lump their 18" and 19" tubes together and make a "one tube fits all", and this shows a little of why there are so many actual Blockley tube sizes, rather than a few tubes with plenty of sizes written on them, like you get from the Classic Tyre specialists.