I've recently built up the CS-821. Coming from the Niner brand of bikes - and all I can say is that the CS-821 is a beast, but it does have its quirks.

One of which I'm dealing with now that has to do with the main pivot. In a nut shell, the current bearing design doesn't work because of a design flaw of the main pivot bearing. Essentially whats happening is that there is a washer on the opposite side of the bolt head that seizes the bearing since it's mounting flush to the top and bottom bearing races, the entire suspension is relying on movement of the pivot bolt, and NOT the bearings like it's supposed to. It's very wonky, and I'm waiting on a solution from Peter. A video description can be seen here. https://drive.google.com/file/d/0B02WptCYHjcEQS13ZkFDRGl4T2s/view?usp=drivesdk

Other than that the bike has been superb, and performs way better than my niner did. The thing shreds!

This is my build (Hope it Helps):



I'm sitting at about 25 lbs as it is right now. I made some adjustments to the build, but nothing too crazy.

I have about $3k usd into the bike. I wasn't too concerned about the value. I just wanted to build up a bike that had exactly everything that I wanted. I always do my best to support my LBSs. This was more of an experiment than anything, and wow did i exceed my expectations. Starting on a fat bike build next.

@exzos - Awesome build, I've been communicating with Peter at XM. I'll be pulling the trigger on my frame and wheels this week. I'm still trying to figure our a few things I'm hoping you can give me some insight.

Is it possible to mount a front derailleur?

Also, in regards to the rear shock bushings, did the 2x22.5 work out as you had planned? Anything that you can remember to look out for?

Any chance you could post a picture of the bottom bracket/crank area. Its hard to see on XM.

Thanks!