Bontrager’s top-level Rhythm Comp trail shorts are heavy but that’s because they’re seriously overbuilt to endure whatever mistreatment you may put them through.
The mesh lining on the outer wicks moisture away from your body well and you get zipped vents on each leg, but they aren’t as breathable as lightweight alternatives. They don’t get ridiculously heavy with sweat though, and the water-resistant fabrics are excellent at shedding gunk sprayed up from the trail.
The inner legs and whole of the rear are stretchy so you get lots of unimpeded movement, and a detachable webbing belt backs up the already elasticated waist. The only problem is remembering which of the six pockets you’ve put things in.
The mesh liner is a decent lightweight option that lets the airﬂow in and it comes with a chamois that, although not the most padded, stays incredibly dry even when you wind the effort level right up.