Abus Bordo Big Plug 6000 Folding Bike Lock - High Security Bicycle U-Lock for Road & Mountain Bikes - Perfect for Urban Commuting & Outdoor Cycling

I really like the ease of carrying this lock on the holder attached to my down tube. I bought one long enough to capture the rear wheel, down tube, and bike rack. Folds and unfolds easily.However, the one drawback of this bike lock is the lock mechanism itself. Many times I have to struggle with getting the key to to work properly. I still use it but it is almost a daily frustration as I use my bike to go to and from work. This seems to be an Abus lock trademark as my ebike battery also locks with an Abus mechanism (different key) and it is often a challenge getting the key in just right.9/23/21 updating - I have found the more I use the lock, the easier the key is works. Before it could take several minutes of fiddling with the lock, now much smoother.