I've tested 3 different handlebar mounted bikepacking systems in the past year. One was a handlebar bag, it worked well but it wasn't waterproof. The second was a harness with a waterproof dry bag, a good secure system but it rubbed the hell out of the head tube of the bike and crushed the cables against the handlebars. So when the Salsa EXP Anything Cradle system became available I jumped at the chance to give it a shot
it consists of a nylon cradle bolted to two alloy arms that attach to the handlebars close to the stem. The double ended dry bag straps to the cradle and if using the front pouch, it's added to the straps that attach to the dry bag.
The angle of mounting the cradle is crucial, too high and the centre of gravity will affect steering, too low and when suspension forks compress the bag will rub on the tyre. The plastic buckles couldn't handle the tension required to secure the bag and loosened off through vibration. No problem, after tensioning the straps there was enough length to tie off the buckles.
the dry bag has attachment points to thread the straps through to stop the bag sliding from side to side. I carried my medium weight sleeping bag and dry clothing in it and it swallowed that up. The front pouch is awesome, ideal for electronics as it is seam sealed and made of heavy duty material that'll take the knocks. I loaded it up w snacks and map as well, it's just so handy to access. I know this is a big call but this system could be the ultimate handlebar bikepacking set up. Available in NZ from Cyclewerks. Salsa Cycles EXP Anything Cradle plus dry bag and Front Pouch.