In my case, I would recruit the gf, we would do a romantic O' Dark Thirty Yarn Bombing mission on the top bar of that bike rack, so that it's nice and cozy snug.

During daytime use I and/or gf could then lift the front wheel of our bike/s up and over that nice, cozy snug, AND SOFT, Knit Stormed upper bar, Then, set bike/s down with nice and soft upper bar sandwiched behind the fork, above the front tire and with down tube resting on top of the top bar of rack.
Then proceed to use your std. size u-lock (sorry minis won't work, neither will short wheelbase, tight geometry bikes) to lock front wheel, top bar of bike rack, and downtube, inside the lock shackle.
Run cable to, or use your mini u-lock to secure back wheel.