Update from my build:

I had a small creak from the suspension, nothing big but annoying.  After ruling things out successively, I determined it was the suspension pivots, so off I went to check them out.  Two discoveries. 

First, the pivots aren't greased at all from the factory, that's going to give you some noise.  Pulling everything apart, greasing the pivots, and reassembling (have your medium thread lock handy!) made the sound go away.  Problem solved.

Second, this gave me a chance to check the bearings, the main pivot is far too rough for a bike which hasn't even seen a full season of riding.  I have ordered replacements, as expected they aren't expensive, I even got the nicer stainless steel ones and only ended up spending $32.  These bearings don't really move that much, so I haven't noticed during riding, but now I know and I want things to be right.

Also a comment for others doing this:  On the main pivot, there are several spacer/washers.  2 thin (<1mm) 3 thick (~2mm), and a cone shaped washer that fits the bolt head, which is also cone-shaped.  The thin ones go next to the main bearings, as they are thin enough to slip into the gap (more important on the drive-side.  I used a bit of grease to hold it in place and then slide it into position.  The order of the others starting from the bolt head:  The large cone washer, 3 thick spacers, finally the other thin spacer.  Torque it down to 20 n-m (my bike torque wrench only goes to 15, so I did that and then a bit more.)

I mention this because getting it out took some effort and when it finally popped free things went flying, and it helps to know what you're looking for. I only found 2 of the thick spacers, thinking that was all of them, only to find the pivot bolt was no longer flush with the frame.  It took my far too long of searching the room to find the missing spacer!  Don't be me.  I tried to find a place to order these spacers, and they are not commonly available, so consider them precious.

Edit:  I figured out what the spacers are, they are pedal washers, so you can order then if you lose them.

Otherwise, the bike is riding really well, I am getting the suspension dialed in, I am also bottoming out the rear suspension more than I think I should, so I added a larger spacer and I am bringing the pressure up.  I'm 100 kg so yeah, probably going to need a bit more stiffness regardless.

I found a youtube video uploaded recently with a a sweeeeet xtr kashima build- discussed by the technician who build it, you can have that video translated via youtube.
the technician is really exaggerating with the verdict on the bearings and the costs of the bearing replacement - its a single pivot, from what i read all over from users,  the bearings are fine - just need extra greasing to be on the safe side.

i didnt really understand the shock hardware issue as well- it is standard and no one reported this issue.

overall a positive video - great looking build
just copy paste the link

I am immediately skeptical of these guys because they say some odd things, like needing a lathe to “fix” the spacers on the rear shock so they fit.  You just buy the right spacers for like $10, there is not an industry standard of shock spacers.  This isn’t a flaw, and you don’t need a lathe to address it.

The comments on the bearings are non-specific, why did there replace the bearings?  What was the actual issue?  Was this a user error issue or a defect or a poor quality spec?  I did look at bearing replacements, they are a standard size and cost like $10 for the main bearings, I can get a set of 4 of the smaller bearings for $20.  If you are building bike up from components I would hope replacing a bearings is not a worry.

Several of the Russian commenters point these things out as well.  Bike stores have a bias, their incentive is to find problems, the only safe choice is to buy from their store.  If this is the worst they can come up with then they found nothing.

The downside of carbons frames from reasonably reputable companies is not durability, it is weight and compliance.  They are often over-built to avoid warranty claims, and they don’t aim for complicated frame flexing modes.  The weight differences we’re talking are like 200g, and the flexing modes I am not sure are noticeable and could just be marketing fluff.

Another downside is fit and finish, better frames have things like built in cable runs and in-frame storage, as well as custom developed shocks and such.

Oh and if you want a super custom paint job like a Trek Project One that’s probably not an option.

thank you so much nallen!

Im thinking on a checklist for this to make sure all goes well.

In retrospec would you guys have ordered somthing as sapre? somthing i better clearfy before the frame is shipped?

Trying to make sure i help the sp people to not screw up

I just installed the Neco headset, and it's so much better.  Spcycle should use these as stock.  I will probably replace it with the Acros when it comes it as it looks like an even better design, and more robust bearings, but honestly, it's just a bike geek upgrade, this neco bearing does all the things at 1/3 the price.

One thing that I had to order that I didn't plan out:  the rear shock bushings!  Bikes are so different that there isn't really a standard size, for the 686: Front 8x50mm, Rear 8x22mm.  And of course a bushing press if you dont have one.  Neither item is terribly expensive, but nearly impossible to work around.

You will need a cable fish line to get the rear brake line and shifting cable through, which you should expect with interally routed anything.

Consider upgrading the bolts/hardware, they are fine, but a bit prone to rust.  I haven't done so yet, but thinking of it.  I need to find a source for the parts.  I might just paint the exposed metal as a solution.

I didn't have any issues with the brake surfacing on the mounts, everything went together smoothly there. 

Consider the grease you are using to put things together, instead of bike grease I am using Mobil XHP 222 for the bearings and seals, it's a lot more robust than most geases, and a lot cheaper.  For suspension bits, and anything moving a faster speeds I'm using a calcium sulfonate grease, it is less prone to attack surfaces like some lithium greases can.  I ran across this great youtube video by Mapdec which actually explains quite a lot: https://youtu.be/WqiTtlVo-xA?si=CxEbj9GcMscli1fj. Totally worth a watch before assembling a new build.

Ah, get it. I weighed mine with the Axle and hanger and shock hardware. Makes sense.

The handlebar is a Syncros bar/stem combo 70mm/ -10 degrees. I am pretty happy with that. The C- clip is also Syncros and made for that stem so I have "holes on both sides instead of only in the front. But I only have the brake hose going thru the frame. I don't have any cable for the lockout of the shock.
And I have ordered a wireless dropper so I won't have to pull everything apart again. Weight penalty yes,  but I am ok with that. The Dropper weighs 688g with 150mm of travel.

According to my spreadsheet the bike is 11,52 kg with this setup which I think is ok for a XL bike. The fork is a bit heavy since it a regular 34 and not a Stepcast, but I bought it at a to good to pass price
I can save some weight by changing tires when these wear out. The ones on the bike are clincher tires weighing almost 900g each. So should drop the weight by atleast 200-300 with lightweight tires.

I have the Syncros -17 70mm it's unfortunately took short, I find I need a 90mm stem, so I might buy it again.  For now separate stem and bar until I get things sorted. 

My build without dropper is 10.95 kg (24.11 lbs), the 4-piston brakes add some weight and I could put a raceday damper in the fork and save another 200g, but I kind of feel like for a 100kg rider it's getting to diminishing returns.  I'm not totally sold on the dropper, it's 600g of weight without clear benefit to a flat-land dweller like me, and routing the cable is a huge pain plus one more thing on the handlebar.

Some images in Sunlight for those of you who want to know the gloss facter on the white paint.

Interesting to see that the same frame differs alomost 200g in weight My XL weighed 1950g or something close to that.

It recently got a small upgrade. New fork, a Fox Factory 34 in 120mm travel instead of the super weird setup with the SID Ultimate SL in 100mm i used at first Feels a bit more balanced now, haha.

I removed everything I could to get a "just frame" weight, that might account for the difference.

Which handlebar is that?  The spcycle one or something different?

For a power meter I switched to the pedal-based favero assioma Duo, modified with shimano XT SPDs.

For tires I am giving the Continental Dubnitals 2.4 a try, I ran race kings for a few years, and they are basically the same thing.

Also giving the ZTTO MS ultralite 10-51 cassette a try, it's been out a while and the chinese game of beta testing on customers may have worked out the problems (I hope!). It's about as light as the XTR and less than half the price.  Shifting seems ok.

I also ordered the shimano M8250 XT Di2 upgrade, it was on spring sale from Aliexpress, and it will remove some cables from the internal routing.  The internal routing is managable, but it is annoying at times.  The headset design isn't great, but workable.  I ordered a different headset design off Amazon ($38) which might address the issue.  The problem is really the C-compression ring and how it restricts the cable placement.  Ideally you would face the gap forward, but if you have a negative angle steam or integrated bar, the bend on the cables/brake lines is enough that things don't work anymore.  The new headest has teh slots on the sides of the headset so that can be routed without this issue.

Updated picture attached for all your peeping desires.

I just received my white  XL M868 from SP Cycle this morning after an annoying hold up with customs (UPS was the problem is seems.). Delivery was prompt from SP, you can't hold anyone accountable for customs into the USA who isn't in the government. 

Everything appears in order, after removing the plastic spacer for the rear shock I weighed it at 1785 g.  Paint looks smooth and well done.  The frame was packaged well without any damage. The interior appears smooth and without any carbon lay up mess.  The BSA BB looks clean, I will find out straightness when I put the crankset on.  The headset is snug and seated well, the edges don't feel sharp enough to cut through the cable housing as was seen on Orbea bikes with similar cable routing. 

The included headset has a UDH to standard derailer adaptor, and the proper bits for a normal fork (a previous post asked this.) The seat clamp I will probably replace with a more robust one, but it's probably fine. 

I will share pictures when it is built up later today.

Attached are some pictures showing details I haven't seen on other posts for those considering.