I built a Niner hardtail last winter. The electric shifting stuff was REAL expensive then...it wasn't even an option. I built it up with GX and x1 stuff, also Magura brakes. Did 27.5+ with 40mm wheels (aluminum). I'll tell ya, for as much as I ride, I don't know that I need anything "better." Once you get to GX (Or XT in Shimano world) you're only saving weight. Functionally, they work about the same, MHO, anyway. I can shift uphill, as long as I'm not standing on the pedals. Its crisp and quick. 1x drivetrains made a huge difference there too.
When it comes to weight...You're building a slack hardtail. They are a riot...but they aren't XC machines. They are really made for sending it down hill and holding on for dear life, LOL. Save the coin, get a cheaper groupset and don't worry about batteries going dead...
Friend of mine sent me this...Made me chuckle...I was one of those nut jobs in the 90s with a full rigid bike!
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The interesting thing is, one of my riding buddies has a carbon Chameleon. It only weighs about a pound less than my steel Niner. his is coming in right around 28 and mine is about 29.
We went to Copper Harbor this year, it was a BLAST.
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