Dunlop made a range of tubs numbered form 0 to 10. The zeros were the lightest, a cotton tub for the track at 6oz. Their heaviest was the number 10 at 17.5 oz a training tub. Constrictor was another well known brand of British tub. These were not sewn up at the base but had their own unique construction. Dunlops did make sprint rims they weighd 12oz. Constrictor already mentioned and how about the short lived excellent Birmalux sprint rims. Anybody got any of these?
Thats all for now. Keep those wheels spinning, in your memories if not still on the road. Be lucky Mick Butler Huntingdon UK.