Originally Posted by
Killer Cougar
I know this question has probably been asked a million times but I am not quite sure where to look for it. So, what is the smallest tire I can put on my mountain bike? .... I was looking at maybe a 26x1.5 or a 26x1.25, but not sure if they would fit.
This depends on the width of the rim you have. Too narrow a tire on a wide rim will tend to result in you getting sidewall damage.
A fair rule of thumb is the tire shouldn't be less than 3/4ths the width of the rim, or wider than 3/2 of the rim (but that's another problem...).
That said--most MTB bikes now come with rims that are around one inch wide (outside width), so you can put tires all the way down to one inch wide (Continental Gran Prix) on them. Either of the two widths you mentioned will likely work just fine.
Also note--when you get narrower tires, you need to get narrower
tubes as well. Running a fat/skinny ture with a skinny/fat tube will lead to
constant flat tires.
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