As above, can anyone point me in the direction of small diameter tubular rims/tyres? I did find some 18″ Panaracers from a wheelchair racing parts supplier but cannot for the life of me find a supplier of rims to suit. Ideally want to keep below 20″.
There used to be tubs to fit Moultons in the 1960s.
No idea if they are still made, but a few of the specialist tubular makers used to be able to build you whatever you want because all their production was handmade anyway. Not likely to be cheap though.
Racing wheelchairs are the key here. Search for the manufacturer and see what they use. This may invilve an email or phonecall to find out what rim they use. Also try people like ICE trikes in SW England. They may have some knowledge. Failing all that try some info ftom paralympic sport organistions.