RE: Lock for Mariner.
Court has a nice over view vid on locking a bike in general.
I have the https://www.litelok.com/
It's rated at the Gold standard purchase overseas shipped to CAN. We bought two and they can be joined together to make one long lock or be used individually (two with the same keys).
The lock feels solid and is a large visible piece.. It is indeed wider and heavier than I pictured in my mind. You can see the lock on my bike back in photos on Page 4 of this thread.
I have struggled to get the lock closed sometimes because I'm a bit of a wimp but it gets easier with understanding. It more like setting a tight spring that would rather stay flat if you can imagine.
It does have a limited circumference as a single lock. The diameter is between 8-9.5" possibly more if you are able to squeeze it into a more oval shape but the might require fighting with the lock and the bike rack more than you'd like. The length when straight is 29"(one lock, not including the interlocking section). It weighs 39.2oz or ~2.5lbs for each lock. Now is that lightweight?
Because the tires are 4" and the spokes from a 20" wheel are closely spaced it leads to complications getting it around the rear tire/frame and what ever you are securing it too. It is possible, but not always. Usually this mean a compromise of just securing the frame to the bike rack or the tire (with the motor). I think I have only once been able to lock it with the rear tire, frame and bike rack. Perhaps it was due to lack of imagination or time.
With two locks joined together you get much more range of use. I could flatten the two together to get a radius of ~25?" (maybe a wee bit more even).. Lots of play to setup around something awkward or fold the bike in half and lock the frame front and back tires
. The down side is you could give potential thief enough play to make it easier to cut. If someone wants something they will find a way to take it. This bike does catch the attention of others so it might be good to lock it down.
The exterior casing looks almost new (minus a few stray bits). Pretty sturdy and seems to shed dirt well.. (unlike my bike)..