Review on Heavy Duty Seatylock Mason U Lock - Patented Diamond Secure Anti Theft Bike Lock With Keys - Ultimate Protection For City, Electric, Mountain Bikes, And Scooters by Affan Yeo

I've had the lock mounted on 3 different bikes now, with varying tube sizes, and each time the mount came loose after 20 min of riding.It's also not quiet. The marketing claims "this bike lock won't make a peep while you ride" but it actually makes a lot of noise. Even if the mount was 100% secure it would make a lot of noise because there is some play in the mounting mechanism. Don't take this lock on your group rides, your friends will thank you.