Reddit mentions of Schlage 12mm Cinch Ring Security Chain (No Lock)

That sucks man. This is why I keep mine chained up under my carport with this set up:

Oxford OF38 Boss Disc Lock with Double Locking System https://www.amazon.com/dp/B0036YYH6A/ref=cm_sw_r_cp_apa_i_b4X1CbGDNYTV8

Schlage 12mm Noose Security Chain (No Lock) https://www.amazon.com/dp/B00X6E0NO0/ref=cm_sw_r_cp_apa_i_A5X1Cb4WJFAS0

I know that it's worked at least once, there's a little cut mark where I assume some asshole broke his harbor freight bolt cutters.

Get this chain https://www.amazon.com/Schlage-12mm-Noose-Security-Chain/dp/B00X6E0NO0?ref_=fsclp_pl_dp_2

Use this lock https://www.amazon.com/Stanley-Hardware-S828-160-Shrouded-Hardened/dp/B001V5IYT2?ref_=fsclp_pl_dp_6

I use this chain

https://www.amazon.com/gp/product/B00X6E0NO0/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

With this lock

https://www.amazon.com/gp/product/B06XCMWW9H/ref=ppx_yo_dt_b_asin_title_o02_s01?ie=UTF8&psc=1

Had to cut off some of the rubber on the lock for the chain to fit through.

First and foremost no chain is cut proof nor is any lock un-pickable. With that being said what you're really shooting for is simply deterrence. Consider where you'll be parking it a majority of the time, and any place you consider to travel to. Ideally, at any location you'd have a secure anchor point. Any such place that'll allow you to loop a chain around or through will work.

When I have it parked outside during the day I use this particular chain to secure it around a fire escape. I use the smaller version to travel with if I know I have a small enough anchor point at my destination. As others have said I'll occasionally simply wrap it through my rear tire in a pinch but it's really a horrible idea. Two people can easily throw it right in the back of a truck if you've "locked" it up this way.

I like those "cinch" type chains as you get a lot more usable length out of them. I've drilled a ~2.xx" hole in my rear plastic and installed a grommet to pass the chain through, locking my frame. (See SpoonKiller's post here to see it in detail.)

As far as locks go there's a million options to choose from. I'm not really that well versed on them so I don't think I'm the best resource. I'd simply look for a lock with a shielded and hardened shackle and some common security features implemented in the core. Here's a great article on the subject. Take a look at #4 on page 4 where it discusses different pins and their effects on pick attempts if you want greater detail.

I've heard multiple people speak to the effectiveness of the stock steering column lock so I always lock that as well. I also used a cover when I had it parked outside which is another low-cost/effective deterrent.

Naw, that’s a noose chain. It allows for a wider variety of locking situations.