Hello Bentley78!
What you want to do is definitely achievable, but as others have said, you'll need to pick your parts wisely.
The Delirium T is designed to fit into the "aggressive All Mountain to fairly serious Free Ride" category and while building it up light is certainly possible, what you don't want to do is end up with a
frame that performs way above the
components that are bolted to it. Or, to put it more bluntly, a frame that is held back by a compromised parts selection. At a certain point, it's going to make more sense to get an Endorphin frame instead...
I have seen Delirium Ts built up less than 33 pounds (even powder coated frames!) and in my opinion, these are probably too light and really out of the "spirit" of how the Delirium T should be built up. However, I have also seen realistic lightweight builds and I think what you want to do is definitely possible. You might want to PM
Gratiflying on the Knolly Forum here as well as he's built up a very "North Shore and Whistler Bike Park capable" Delirium T around 37 pounds (with a Totem, Cane Creek Double Barrel shock and DH tires on it).
Based on what you've posted, I think that you're on the right track. I'll throw some ideas out here that I think will help you out. However, the two places that you will NOT want to skimp on performance to save a bit of weight are going to be
suspension and tires.
Anyway, here are my ideas:
Frame: definitely go with an anodized colour and with the 135 QR dropouts. Anodized frames are a little bit lighter weight than powder coated frames.
Rear shock: no brainer on this one: Fox DHX 5.0 Air. It performs well, and is the lightest, most reliable AM / FR air shock on the market.
Fork: I'm glad to see that you've already selected the Fox 36 Float RC2 because that would have been my recommendation as well. The only question is whether to get a 1.125 or 1.5 steerer tube. Usually I would recommend 1.5" without hesitation, but i think in your case, probably a 1.125 steerer would be better because there is a much better selection of AM stems in that size available. I'm guessing that you'll probably run a 70mm stem length on the bike? Two great products would be the Thomson Elite and the Chromag Ranger stem. Both hit the weight / strength curve pretty nicely and are high end products fitting of the Delirium T. Also, Cane Creek's new 1.5R headseet (i.e. for 1.125" steerers) is pretty trick and uses a zero stack upper cup which might save a bit of weight, but I don't know off hand whether it or the CK headset is lighter weight. If you're planning to use a 50mm stem, then the 1.125 vs. 1.5" steerer decision is a little bit harder.
OK, the rest of this is going to get a bit more complicated and again, as others have mentioned, probably require a few dollars as well
Drivetrain: you mentioned XTR and that is definitely a very valid choice. However, you didn't mention which crankset you're planning to use, ,which will obviously make a big difference weight wise: i would definitely ensure that unless you're a fairly lightweight rider, that you use something along the lines of an all mountain crankset (or if you want to splurge, XTR). Any ideas what you're thinking about here?
Chain guide: this is a big one because it can affect the weight easily +/- half a pound or more. I'm assuming that you'll be running a two ring crankset. An E-13 DRS, which is our standard two ring chain guide, adds easily a good 3/4 of a pound to a build. It's a great system and very easy to install, but if you're looking to drop weight and still want a front derailleur, then there are other solutions that will save you grams. We see a couple of different options here: Raceface has started shipping their Atlas cranks with a lightweight aluminum bash guard which will is about 130 - 140 grams lighter than the stock polycarbonate E-13 bash guard. However, it's definitely not as durable and also probably doesn't have the retention capability that the stock DRS bash guard has but does seem to work pretty well overall (i.e. we don't hear about people dropping their chains all the time when they use the Raceface bash rings). The other solution that we see used quite a bit is the Black Spire Stinger mod. You'll need a ISCG05 Black Spire Singer and you'll have to cut the top of the Stinger back plate out so that it won't interfere with the standard E-type bracket that comes with the SHimano E-type front derailleur. There are some lightweight (i.e. around 50-60 grams) bash rings on the market, so one of these would probably work well with the Stinger and they seem to keep the chain on pretty well.
Tires: I don't run tubeless, but I wouldn't run less than a 2.3" tire. Personally, my favourite tires for lighter Delirium T builds are the foldable Maxxis 2.35 Minions, or the Big Bettys. I'm sure others here will throw in their opinions as well.
Wheels: Again, since I personally don't use tubeless tires, I'm probably not a great source of information regarding tubeless rims. But for a good solid, relatively light wheel, it's pretty hard to beat a classic build with a DT Swiss or CK hub (or a Hope or Hadley) with some butted spokes and a decent rim. Of course, you could do some I9 wheels as well (probably the Enduro). Either way, you'll (obviously) get a 20mm TA front hub and a nice option is a 10mm Thru-bolt rear hub so that you can use DT Swiss' WRS 10mm quick release axle.
Seat post / saddle: The WTB Rocket is a great choice: Ti rails are the lightest of course, but are lots of $$$. The hollow Cromo railed Rocket Pro is almost as light as the Ti version and significantly cheaper. The Thomson Elite post is another no-brainer.
Brakes: there are lots of good choices, but one thing that I would consider if going down to a 160mm rear rotor and possibly a 180 front rotor if you're not too heavy. This can drop a surprising amount of weight. I recently weighed a Magura Louise 203mm rotor with its caliper adapter and then a Louise 160mm rotor with its caliper adapter and there was a 95 gram difference! So, that's an easy way to drop a bit more weight off the bike and is probably more in line with your All Mountain build on this frame.
I think that's it! Keep us up to date on the build as I'm stoked to see how it turns out!
Cheers,