Originally Posted by cerewa
The wheel probably won't fit. If you have rim brakes, the brakes you have will not accomodate the difference in rim diameter (which would require the brake pads to be able to move by ~33mm, or 1 1/4 inch.
The narrowest, lightest 26" MTB wheels available are pretty narrow and light-- and the same goes for narrow light tires. I've seen 26x1.0" slick tires before.
They are but the ride is harsh and uncomfortable without a suspension fork in front. Good in theory not so good in practice. I'd go with a road bike if you want to ride with skinny tires.