yeah definately wheels and tyres!.

I've put a lighter wheel set and tyres on my Kona Coiler and it made a big difference... bike felt lighter and more agile.

Also if the tyres are those specialized chunder (or similiar 2.4) they can drag lots i hear. I use Maxxis high rollers front and rear 2.35 single ply (super tacky on front) and they seem to be good for everything!.

Has it got a heavy duty chain tensioner on?... try taking that off for a ride too.

I put a pair of Hope Hoops (Pro II and 5.1's) along with lightweight tubes (95g) and Schwalbe Nobby Nic 2.4's onto my Enduro.

They altogether saved 1.6kg over the previous OE wheels, Maxxis Minions and heavier tubes.

Also look at an XTR cassette.

I did a similar thing to my Reign and got it a pound lighter for not too much expense:

 Xpedo Mag pedals -  saved half a pound

WTB Tit-railed saddle -  saved half a pound

Tit-rails?

How do you save half a pound on a saddle, what the hell did it come with?

He got big fat ass!!

How do you save half a pound on a saddle, what the hell did it come with?

It came with a WTB steel-railed jobbie, which weighed in at 425g

I replaced it with a tit-railed jobbie which was 195g

saving 230g or approx half a pound.

A lot of saddles are reet heavy yous knows kidz

Everything said thus far is definatly worth considering.

Though as far as saddle / seatpost combos go, SDG I beam and saddle seems to be the lightest combo and damnsome strong according to DH circles - its whats going on my Glory to replace the 600g RF combo thats on there now when I bust a saddle next. 

Don't get an XTR cassette, that's a waste of £100 if you just wanna save weight! XT achieves the vast majority of the saving for half the price!

Tyres, wheels, seatpost, bar, stem, grips, saddle, pedals, chainset can all be far lighter without comprimising strength I'll wager!

Hmmm..chainset is a tricky one for an SX Trail though; needs to be strong enough to cope with all the bike is capable of.

Out of interest has anyone any suggestions for a strong/light crank set? I was half think about replacing mine..

If any of you guys want a cheap weight saving i recommend the Ritchey WCS foam grips wholeheartedly.  Honestly, they weigh next to nothing, they cost £7 and they really are comfortable and grippy.

I use ODI lock ons before that (Got a nearly new pair of yetis and Lizard Skin Logo) and these offer even more comfort and nearly as much grip.

I have replaced all of the above said items on my hardtail.  I have a reasonably light wheelset, lightish bars, stem, seatpost etc.  The thing that i havent changed which seem to weigh a ton are my forks.  Unfortunately unless your frame & forks are lightish you will always be struggling to save big amounts.

Unless you're a total animal most HT2 jobbies will be tough enough, the Athertons are running XTR ones, there was a DH version of the original hollowtech M950 XTR, so the new ones should be plenty tough enough.

If you've got a lot of money THM-Carbones Clavicula DH is unbelievably light.