Can I build up a 4x or DS frame for use as an XC hardtail? I'd be thinking of using normal components and probably 80mm or so forks on it. Would everything be WRONG?

angles will probably be ok. frame will be overbuilt!

TT might be very short though – reason i got rid of mine.

It'd be for my girlfriend, so that may be no bad thing. I kind of twigged that the frame would be a bit of a beast 😆

I had a dmr sidekick that i did just this with moved all my bits form one bike over onto it and rode it as a winter play bike.

was good fun but hard work climbing because of the short TT for a little person it'd be ace.

(it's for sale? cheap…)

More theoretical at the moment. Maybe when summer comes and we've got some cash.

My bike (14" orange msisle) was originally intended as 'a bike built without compromise for the seriously hardcore dirt jumper, street rider or 4X racer.'

That's why I use it for xc… 😕

Should be fine, only thing to watch out for is funny seat tube angles on some frames.

I used to have an Orange MsIsle (16") which also did very nicely for this sort of thing. I got it because I wanted a bike for everything but mainly used it for XC. Now I have replaced it with an Azonic Steelhead because I wanted something steel.

I used to have an Azonic DS1 that was great fun at the trail centres and stuff.