I just upgraded to a Trek Crossrip 3, after having commuted with a flatbar trek hybrid for several years. For the majority of that time, I had my u-lock mount clamped to the vertical bar of my bike frame (the one that the seat-post resides within). Now, I don't mean to paint myself as someone who lacks ingenuity, but I saw this photo on a post that was from back in 2015, and I'm new here, so I can't send pvt messages just yet.

Looking at the attached photo, which is not mine! (photo-credit to user 'jaxgtr'...nice bike btw!)...

I would like to know how to go about hanging the U-lock on the rack like that, in that specific position. Also, was it a sustainable solution? i.e. secure? noisy/quiet? other issues?

If it is simply attached to the rack using the supplied u-lock mount, then I can't see it. I know that using mine to do that seems like I would have a large protrusion from the rack(from the lock mount), and that doesn't appear visible in jaxgtr's pic.

Thanks for any advice that -anyone- may offer on this. My new bike will not accommodate the lock in the same position as my old bike did, and to be honest, the position on my old bike frame was never something that I loved.

Al depends on what you use to hold it on,, leather straps with buckles, is well tested over millenia, for holding things.

Tubus and Abus, both in Germany collaborated in the LOCC rear rack,
It integrated the 2 so it fit a set of panniers on the outside and held the lock on the side towards the wheel , on the Left side..

Thank you fietsbob. I am working with it, trying to find ways to mount it on the rack in a way that give me the flexibility of just clipping on the u-lock, or in the event that I want to put both bags on, that the mount allows for the bag to be put on and the lock can be thrown in the bag. I also have my fender rods coming up in between the wheels and the rack so while there is likely a way to squeeze it in between the rack and the wheel, that does make that a bit more complicated.