Originally Posted by KC8QVO

Review from Amazon on this lock - 14mm chain version:
https://www.amazon.com/Kryptonite-Yo...-goods&sr=1-10

"Bought this for my son to lock his bike at college, in the rack at his dorm. Second night it was cut by a thief and bike was stolen. I realize now it was a poor choice, and should have gone for the solid U-shaped lock instead of this."

Click on the 1 star ratings for the above product page and you'll find the poor reviews. Most of the bad ones are the lock mechanism jamming up. However, there are lubricants you can use to mitigate that issue.