Blockley Superior 550L16 thick correctly 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 are metal tubes available marked 550/600/650x16 which just demonstrates that the people doing this dont know what they are doing. At Blockley we produce a bespoke tube for the 550 size because we know this is much better solution. This 550L16 tube is an excellent fitment is a standard 600x16 tyre also.