It will be a cross country hardtail. I’m 5’6″, ride a roadbike with a 53 cm tt. At the moment i’m riding a 14″ SC chameleon (the old one), which doesn’t seem too cramped but has a retarded amount of seatpost showing (almost max on a 410mm Thomson post).

I don’t really know about sizing mtbs. Road bikes top tube length is crucial. Is it the same deal?

Go to a shop a sit on a few – all manufacturers sizes s,m,l, etc are different and web sites may size you up differently too.
You’ll be a small frame though I would think – easier to chuck around

Giant a small, Kona 16″, Orange 17″ there the only ones I know.

Thanks, i thought basically going for ‘small’ would be right. Just not sure about how big the difference would be between, say, a 15″ and a 16″ (or a 21.5″ and a 22″ tt)?

I know trying for size would be best but i will probably order mailorder and i don’t want to dick a bikeshop around by using it like a fitting service only.

My lads your height and is on the limit of his 15″ Spesh.