So--At long last I am back and picked up the carbon wheel/rim! Fortunately, the post office was able to hold it for two weeks for me no problem.

First impressions, the rims are gorgeous. Looks exactly as shown in the previous pic, with the exception of silver nipples. I also observed the rear wheel (assembled) seems to be built quite well. The tensions are fairly consistent and the rim is dead true/round. I will be lacing and tensioning the front rim this weekend.

Weights:
Front rim (bare) 752g. This is a little more than I expected but still quite light.
Rear wheel, assembled (no axle) with Sapim D-LIGHT spokes, Novatec 202 hub and Shimano freewheel: 1370g
Front wheel, unassembled but with the hub, same as above spokes and nippes: 1170g

This gives a wheelset weight a little higher than advertised (2440g versus 2540g actual). Perhaps this is due to the 3K versus UD selection or mfg variance? An astute reader might note that I'm using a different front hub than shown on xmcarbonspeed.com, although mine is still the same model Novatec and is narrower (135mm vs 150mm). I also ended up with lighter spokes than "stock", the D-LIGHTs are supposedly ~50g/wheel lighter per wheel.

Regardless, I am now able to assemble the bike and will update you guys when I can!

Cheers
R

How's the build going? Your stuff showed up and then *poof* no more updates!

Nosy minds wanna know!

Haha-- I see. Well, I've been on travel abroad for work and actually haven't set my eyes on the wheels yet (or the MTBtools spacer, for that matter). They're tortuously waiting for me at the Post Office.
I should have them in a week or so. Rest assured, my nosy friends... you will be updated! 

Side note: The UK has some incredible bike magazines + unique brands of stuff that you don't see here. One specific difference I noticed is that in the States, it seems like 9/10 of the magazine photos are insane jumps or manuals. You almost never see two wheels on the ground, much less on a flat trail. Too boring for American eyes? No ad retention?

3K Wheels

b) ROVER. Yes. Do this thing. I LOL'd when I saw that.

This is essentially your idea, sir!

I do like it, and the cost of the replica emblems is about the same as any sort of custom vinyl decals. I was originally thinking "Endeavour" or "Saturn" after the NASA vehicles, but the Rover is a bit more "down to earth" (pun intended).

Looks like Chris might be able to help me out!

Here's a selection of pics that I took to help dimension the new spacer:

The lower 52mm bearing cup of the frame:


With the bearing installed:


With the original crown race/baseplate sitting on the bearing:


You can see here that the headset/frame is designed to have a semi flush (+1mm) fitment with the fork.

A point I want to add here: with the crown race/baseplate installed on a 1.5 steerer (at the 1.59" section), this particular race opens up to an OD of 52.2mm, which is larger than the 52mm opening in the bottom of the frame. This means, with the fork test fit, it rubs! Its a little bit of a bummer--I thought at first that I just hadn't torqued down the headset, but on closer inspection/measurement it was clear the race was rubbing the frame.

Here's the 1.5"  carbon headset spacer installed as a test:


This test confirmed for me that adding 8mm (underneath the baseplate) as a shim is just barely enough to clear the fork knobs. Since I'm having a custom part made, I'm actually going to go +11mm instead of +8mm to give everything a touch more room.

On my steerer, the 1.59" OD pressfit section is just tall enough to grab after an 8mm shim:


Another 20 min in Solidworks, and here is the drawing for the baseplate adapter I hope to have made with MTB Tools :

If you've got the ability to machine a part, maybe make a replacement crown race that has the 8mm thickness built in? My concern is the crown race is press fit on the top of the crown (bottom of the steerer tube) and it steps down in diameter just above that, so you'll have a crown race with play if it's being held above the top of the crown.

Barring that, maybe install the crown race, then have the spacer on top of that and interfacing with the bearing? At least the crown race would be press fit to the top of the crown at that point. You'd have to machine the top of the spacer with the right angle/diameter for the bearing, though. If you can machine a tube to 1.59" accurately, that shouldn't be too much of a problem.

Also, I'm unsure where the Ferrari fits on the fat bike. ^_^

I thought about that--just machining my own race. There are a couple issues though I'd imagine:

• The race is steel, I'd like to stick to AL as steel is harder to cut and weighs 2X.
• The race indeed has a very specific angled cross section to match the sealed bearing that might be tough to match. My lathe skills aren't terribly great--even hitting 1.59" accurately will be tough for me.
• I want to be able to change the race if I need to.

From looking at the Mekkem steerer tube, there is just enough shoulder in the 1.59" section to allow the race to still be "press fit" on top of an 8mm spacer. If not, my Plan B is to make a 5mm spacer and buy the commercial solution for Salsa bikes / CaneCreek headsets available a Bikeman.com for $20. It's a replacement crown race that is +3mm thicker to render a Salsa fatbike compatible with the Bluto, and I believe that that race is compatible with the headset I got with the frame.

For reference to others, here is the short aluminum tube stock I ordered from Mcmaster ($3):
http://www.mcmaster.com/#catalog/121/3680/=zhv6bj

And here is the +3mm headset race for the Salsa fatbikes:
http://www.bikeman.com/HD8880.html

I'd say that the wild ride of your full suss in tight sections is probably more due to wheelbase, steering angle, stem length and BB position than wheel size.

For XC, I'd really vote 29, regardless of your height.

Here's the video:

https://www.youtube.com/embed/6QBRjp9-uJg