OnGuard BullDog Series U-Lock - 4.5 x 9" | Combination
Locks
OnGuard BullDog Series U-Lock - 4.5 x 9" · Combination
OnGuard BullDog Series U-Lock - 4.5 x 9" | Combination
The OnGuard BullDog Series U-Lock is built for cyclists who want serious security without the key fumble. Read the overview
At a glance
- Lock Type
- Combination (no key)
- Mechanism
- X2P Double Bolt combination
- Shackle
- 13mm hardened steel
- Interior Dimensions
- 4.5 x 9 inches
1 in stock
Free shipping on US orders over $100.
- 30-day returns in new condition. Read the return policy.
- Price matching. Found it for less? See how it works.
Overview
Why Is the BullDog U-Lock a Top Pick for Cyclists?
The OnGuard BullDog Series U-Lock is built for cyclists who want serious security without the key fumble. The X2P Double Bolt lock mechanism engages both ends of the shackle simultaneously, making it exponentially harder to defeat than single-bolt designs. The 13mm hardened steel shackle provides a full circle of cut resistance, giving you confidence at any rack in any neighborhood.
At 4.5 x 9 inches, the BullDog offers a practical locking footprint that fits most bike frames and standard racks without excess play for a pry bar. The combination format removes the need to carry keys, making it ideal for riders who prefer a streamlined kit. It's a well-priced, high-protection lock suited to urban commuters, café racers, and anyone parking regularly in moderate to high-theft areas.
All the specs
MPN 8010C
- Shackle
- 13mm hardened steel
- Lock Mechanism
- X2P Double Bolt combination
- Interior Dimensions
- 4.5 x 9 inches
- Lock Type
- Combination (no key)
FAQ
Good questions
Get to know OnGuard
There's more to OnGuard than this one product. Our OnGuard page has the full OnGuard lineup we carry and more about the brand.
Visit the OnGuard page →What does the X2P Double Bolt mechanism do?
It locks both ends of the shackle simultaneously, creating a full circle of protection and making it significantly more resistant to cutting and prying than single-bolt locks.
Is the BullDog combination lock resettable?
The BullDog combination is factory-set and not user-resettable. For a resettable option, see the OnGuard Terrier cable lock.
What size bike will the BullDog 4.5 x 9 fit?
The 4.5 x 9 inch interior fits most road, gravel, and mountain bike frames when locking through the frame and rear wheel to a standard rack or post.
Reviews
What riders say about the Lab
“Paul does a great job. He got my bike I bought from someone there in their town and had it packed and shipped to me in Austin, TX… It got here in perfect condition!”
“Fantastic store. It has everything you may want/need for cycling. Great team. Highly recommend to anyone looking for cycling related things and bike service.”
“I recently got back into biking and wanted to add some things onto my bike. They had most of what I was looking for in shop… I'm really happy to have found them.”
Questions about this one?
Not sure on size, compatibility, or whether this is the right one for you? Ask us. A real person here will answer.
Goes straight to the Lab with the product you were looking at attached. No newsletter signup.
