This is a fairly standard set-up for many pragmatist cycle tourersCheesewheel wrote:another option if you have a long fork stem with a ton of spacers and a cycling ethic that values pragmatism over aesthetics is to take out the spacers and replace them with a second handlebar stem mounted with the same plumbing pipe. You can use this exclusively for mountingthe handlebar bag while leaving the conventional handlebar real estate completely free for garmins lights etc or even a handlebar roll if you are seeking more of a bike packing set up
But seriously, SJS Cycles sell a special t support for just such a purpose.