Embarrassing question about knobs

Ubersonic

Feel embarrassed having to ask something that's so basic however I cannot find the answer anywhere. Do the knobs on MTB tyres count towards the tyre width? I.E on a 2.4" width tyre is 2.4" the width of the base the knobs stick out of or is it the width of where the knobs extend?

(I'm comparing rolling sizes of knobbed/slick tyres and want ~= size)

Thanks.

rockmonkeysc

No they don't.
Mountain bike tyre widths vary a lot. A 2.5" tyre from different brands (even different models from the same brand) can vary in actual width quite a lot. The width of your rim will also effect the width of the inflated tyre.
Knobbly tyres are usually a lot wider than slicks. Why do you want the same width.

Ubersonic

Thank you, I don't want the same width but I was worried that if the slick was slightly bigger (2.4) than the stock knobbly (2.25) then it may foul on the fork, however if the knobs aren't included in that 2.25 then won't be much of a difference.

Thanks.

JBA

If you are changing to slicks why do you want such a wide tyre?
The whole point of slicks is to reduce drag / rolling resistance. Therefore it is better to go narrower.

oodboo

Never tried them but apparently schwalbe big apple are a good, wide city tyre.

step83

Ive some big apples. They are surprisingly comfy around town, ive a pair of 2.1"s lurking for when I can be bothered to put them on again