550/650x17/18 Inner Tube
A Blockley 550/600x18 thick correctly dimensioned butyl perfect inner tube, with rubber valve stem. Blockleys are the best you can buy, whether its tubes or tyres. Always use a rim band which we also produce.
All other tubes available elsewhere today are very multi size dimensioned and those marked with 550x18 size are always too big, so quality issues aside, don't fit them! This is why we make Blockley tubes, to rectify what has been and is going on.