+1 on Enve carbon mountain bike bars.
My Trek Supercaliber came spec’s with a Kovee XXX 35 bar in 720mm with a Bontrager knockblock alloy stem. While it was ok on short rides, on longer marathon rides my hands and wrists took a beating. Initially I thought it was an issue with the SID Ultimate, but dialing that didn’t solve the problem.
Switching to an Enve stem and M5 straight carbon bar at 760mm made a world of difference. The handling improved with the slightly wider bar and my hands and wrist pains went away. The bar is not at all flexy, but clearly helps with dampening things.
I’ve run the older Enve riser bar on a trail bikes (Niner RKT 9 RDO spec’d with Fox 34 SC 120 mm) and it also performed very well.
Of note, I have ridden some Niner carbon cockpits as well and they were also very good. I think Niner is a little under the radar with the quality of the bars, stems and seatposts.
Enve seems to do things with their carbon layups that just seem to work. With the Supercaliber I thought I would give the Bontrager set up a go but was really disappointed with the feel and narrow spec’d bar. Seems an odd choice for a modern XC bike.