Ok thanks, I see your point regarding ribbed inside surface, why do tubed tyres require tubes when fitted to tubless wheels , is something to do with the way they seal around the wheel ?
Yep, it's all about the seal with the rim. Morgan spoked wheels used to need tubes in the days when the spokes weren't sealed and there was just some rim tape to protect the inner tube.
Nowadays they are sealed with a layer of silicone and so you can use tubeless tyres.
