Blockley Superior 550L16 thick correct sized butyl inner tube with metal nickel plated valve stem, as the stems were in period.

Nothing you can buy even comes close to this inner tube, which is produced on new Blockley tooling. We have observed that elswhere there were race tubes available marked 550/600/650x16, but at Blockley we produce a bespoke tube for the 550size because we know this is much better solution. This 550L16 tube is an excellent fitment is a standard 600x16 tyre also.