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  • Hefty 13mm (0.51 in.) hardened steel shackle resists cutting, prying and jacking; rubber-coated shackle and crossbar help protect your bike's finish
  • Dual lock down mechanism secures both sides of the shackle for excellent pull resistance
  • Bump-proof Z-Cylinder tumbler resists picking, pulling or drilling
  • Rounded design and centered key hole eliminates pry points; extra-thick, molded end caps protect against bumps and hits
  • Comes with 5 laser-cut keys, 1 of which has an integrated LED light; mounting bracket Included
  • OnGuard rates the Bulldog LS U-lock as a 63 out of 100 on its 100-point security rating system, where higher-rated locks offer increased security


View all OnGuard U-Locks

REI membership


Best Use Bike Commuting
Lock Style U-lock
Lock Type Key Lock
Lock Thickness (mm) 13 millimeters
Material(s) Hardened steel
Dimensions 11.5 x 4.53 inches
Mounting Frame
Weight 3 pounds
Rated 5 out of 5 by from Gold I purchased this after someone tried to cut my cable after having no success cutting this same lock that was on a bike parked next to mine. I'm a college student and my bike is not near top of the line and the one that was parked next to mine was worth over $6000. I thought to myself, if they could not get the bike worth that much with this lock and thus diverted their attention to my bike, I think that mine will be safe too, if I use the same lock. This has been the case. It conveniently mounts anywhere you want on the frame of the bike, this makes for convenient access and prevents loss or forgetting it when you go out (especially when in a hurry). Overall, so far it has been a worthwhile purchase.
Date published: 2013-01-09
Rated 4 out of 5 by from Does its Job, Probably Won't Last I bought this lock on sale and it has done a decent job so far. I mounted it on my commuter road bike and it's hard to keep out of the way because it's so big and bulky. The locking mechanism I can tell isn't built to last. I'm waiting for the day when my key breaks (you get like 6) or the locking mechanism breaks. It feels pretty touchy when you put the key in and turn it, and sometimes it takes several tries to get the key to line up right so it will open the lock. I put heavy as a drawback only because I use it on my commute and it's either in my bag or mounted on the bike, but some people may see that as a plus since it IS a lock. I might buy a different brand next time just to see if the locking mechanisms are all that flimsy, but I'd recommend it.
Date published: 2012-07-18
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