very confused by tyre sizes!

ianbar

i need an inner tube and tyre for my turbo wheel. i had bought both thinking they were 700c but actually just realised its a 622c? is this normal? im quite confused now!!

LeicesterLad

622 is a 700...erm, i think?

ianbar

well unless i am doing something very very wrong the innertube and tyre too bigger than the wheel! put uinner tube on pumped it up and its buldged away from been too big?

wishitwasallflat

Yes 700 is the same as 622 - if in doubt ask Sheldon

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


ISO, the International Organization for Standardization has developed a universal tyre sizing system that eliminates this confusion. (This system was formerly known as the "E.T.R.T.O." system, developed by the European Tyre and Rim Technical Organisation.)

The ISO system uses two numbers; the first is the width of the tyre or rim in millimeters (The actual tyre width will vary a bit depending on the width of the rim. The rim width is the inner width measured between the flanges as shown in the diagram.)

The second ISO number is the critical one, it is the diameter of the bead seat of the rim, in mm ("B.S.D."). Generally, if this number matches, the tyre involved will fit onto the rim; if it doesn't match, the tyre won't fit.

For example, a 700 x 20 C road tyre would be a 20-622; a 700 x 38 hybrid tyre would be a 38-622. The width difference between these sizes would make them less-than ideal replacements for one another, but any rim that could fit one of them would work after a fashion with the other.

wishitwasallflat

What width is the tube - usually a range like 20-25 or 28-32 - if its rim 622 it should fit a 700 rim wheel as they are the same just a different system of labelling re my post above - check out the article.

LeicesterLad

622 X 13 is standard sizing for 700c tyres. Problems fitting usually concern width ( X23 X25 etc) and 'some' 622 X 13 rims will strugle to take anything over a 25. Unsure how you come to have your problem though?

ianbar

just glanced sheldon, yeah seems it should fit. very confused! will have another stab at it tomorrow but im sure it wouldnt fit. admitidly i have never done this before so could just be making a stupid error!