What size tyre?

mathie

Hi
My wheel says "18-622 for rims 622 x 15 - 18c/15c"

Does that mean that I can only use 700×18C tyres?

thanks
m

quozl

The 15mm is probably the internal rim diameter, so you can use something between about 23 and 32mm - http://sheldonbrown.com/tire-sizing.html#width

Rims can support a range of tyres width depending on their internal width. There's no way you can only use 18mm width tyres. If your rim is really a 18mm internal width - that text on your wheel is really confusing! - then a tyre of 25mm+ would be needed.

Would you not have an old tyre that came off it to check?

cdaly_

I'm assuming that this is printed on the rimtape covering the spokes. The actual rim width may be printed elsewhere on the rim and will just say something like '18-622' and nothing more. You can fit tyres up to around 28mm on a 15mm rim and from around 25-40 on a 18mm rim.

mathie

Thanks for that

So if I get a 25c tyre what tubes do I need?
18 - 25c?
18 - 28c?
Does it matter at all or does the 25 just have to be between the lower and higher value of the tube?

quozl

Doesn't matter as long as the 25 is in the range covered. That said, I'd try to have it be at the higher end of the range covered as that'll be a smaller and lighter tube assuming the same models. So I'd prefer 23-28 to 25-32, for example.