I've always know 26", 27.5" or 650b's and 29" or 700c's ... but I keep coming across 28" .... is this in essence the same 622 as the 700c but just a narrower tyre which reduces the overall diameter.
Just checking before I order the wrong tyres online.
I seem to remember that 28x1.5 or less they were actually the same as 622xzXX or 700c. So some 28" tyres are actually 700c but it depends on the width or something vaguely vague like that. If you Google Sheldon brown you will find everything you wanted to know about everything bike related and then some including stuff on wheels and tires. Although you'll have to put up with him spelling it tires cus he was 'murican.
As above. A small 29er (so 29x1 ish) might actually be 28. Hence 28. Schwalbe often use this sizing.
Cheers for everyone's help and thanks for the link to the Schwalbe page as well ... very useful !!