550/650x17/18 Inner Tube
A Blockley 550/600x18 thick correctly dimensioned butyl perfect inner tube, with rubber valve stem. Blockleys are the best tubes you can buy, as quality aside, they are correctly dimensioned. Always use a rim band which we also produce.
Note that ALL other tubes available elsewhere today are for fitting in too many tyre sizes! And those marked with the 550x18 size are always too big, so quality issues aside, don't fit them, because they are the wrong size! This is why we make Blockley tubes, to rectify what has been and is going on. At Blockley for larger rim 19" tyres we have different tubes . . .