I've never been entirely convinced by the fat tyre route. . . I mean, yes, on a rigid, small-wheeled bike I'm going to use fat tyres, but the drawback is much more rotating mass, so whilst you're not adding a huge amount of weight to the bike you're adding it where it matters most in terms of ride quality. That's why I spend the extra and get folding bead tyres. The maxxis grifter on my rear wheel has performed well and weighs under 400 grams whereas a standard Big Apple according to my scales is over 600.