When is 26 inch not 26 inch..?

So, my ultra cheap 26 inch tyres arrived today, however when i attempted to size them up against my ultra cheap 26 inch rims i discovered that the rim will happily fit through the centre of the tyre with about a centimeter to spare all round...

So how much can 26 inch wheels vary? Are there different types of 26 inch wheels?

Thanks

http://sheldonbrown.com/tire-sizing.html

Yep. I'd just posted a warning in your current project post, looks like I may be to late. :(

Not overly concerned, the tyres were only £7.50 each!

http://www.ebay.co.uk/itm/400256224268?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_500wt_1127

I believe the rim i wish to use is actually from a very cheap 26 inch mtb... So what would be my best bet to find a narrow tyre to fit?

If you want cheap and narrow for the wheels you have I'd just head to Wilkos, or Decathlon. It's probably the most common size. you probably want 26 x 1.8, but worth checking the width will work though as your frame is likely designed for 700c or 27" rims.

so the tyres i have purchased are most likely to be for 27 inch rims? the iso numbers are 32-597

So how much can 26 inch wheels vary? Are there different types of 26 inch wheels?

Thanks

Yes, you bought 26 x 1 1/4 tyres (what you get on old raleigh 3 speed bikes) but what you probably needed was 26" MTB tyres.

so the tyres i have purchased are most likely to be for 27 inch rims? the iso numbers are 32-597

Nope, 27" are 630mm diameter, 700c are 622mm! And mtb 26" are 559mm

your tyres eare as the OP stated more likely for and old 3 speed from the 50s and 60s.