Air free tyres, tyre sizes

http://www.airfreetires.com/

Such things as air free tyres always - rightly - attract a lot of interest. I can't comment on the quality of the products here, but be very careful of the sizing information here - much of it is wrong. I've come across someone who bought 37-305 tyres fro his Brompton. The only reason he didn't realise they won't fit is that the poor so-and-so has had his bike nicked. I found out about it when he tried to sell his tyres.

The website claims that 37-305 tyres are a substitute for 16 x 1 3/8 tyres. Nonsense! This can be clearly seen if we stick to the only reliable yet undeservedly least familiar tyre sizing system - the ISO one, in which 16 X 1 3/8 tyres are 37-349. The large number is the diameter at the bead and as is obvious they are 44mm larger that the 305s. The smaller number is the width of the tyre - not so critical, but its probably best to buy the same size