Over 2,000,000 Million Customers Served!!!

Need Help? Click the Live Chat to Talk to a Gearhead 💪

Enjoy Free Shipping on Orders Over $75 – Available Within the Lower 48 States!

SKU: LK8013

OnGuard Bulldog Series U-Lock 13mm Hardened Steel Shackle, 3.5 x 5.5" Keyed Lock with Anti-Theft Guarantee, Ultra-Strong Bike Lock for Maximum Security, Includes Mounting Bracket

Regular price $39.96
$49.95 Sale price $39.96 Regular price
Sale Sold out
Unit price
/per 
Save 20%
  • Free Shipping Over $75
  • 30 Day Returns
  • Satisfaction Guaranteed!

$10 Gift Card

at 250 points

$25 Gift Card

at 500 points

$75 Gift Card

at 1,000 points

This is a pre order item. We will ship it when it comes in stock.

$10 Gift Card

at 250 points

$25 Gift Card

at 500 points

$75 Gift Card

at 1,000 points

Description
Specifications

Secure Your Bicycle with the OnGuard Bulldog Series U-Lock - 3.5 x 5.5" Black/Yellow

Maximize your bike security with the OnGuard Bulldog Series U-Lock, engineered for unbeatable durability and resistance against theft. Featuring a robust 13mm hardened ultra steel shackle, this high-performance bike lock provides a formidable barrier against cutting, drilling, and picking attempts, ensuring your bike stays protected in any environment.

Premium Materials & Construction:

Constructed from 13mm hardened ultra steel, the Bulldog U-Lock offers superior strength and resilience. The shackle is fully reinforced with a sleeve over the crossbar and cylinder, adding an extra layer of security against anti-drill attacks and theft attempts. Its high-quality black and yellow finish provides a sleek, professional look while enhancing visibility to deter would-be thieves.

Innovative Performance & Engineering:

Designed with X2P Double Bolt Lock mechanisms, this lock provides double the security, making forced entry extremely difficult. The lock's 4.6-ton pull strength ensures maximum resistance against smashing and levering tactics. Weighing only 2.3 pounds, it offers a lightweight yet formidable security solution, perfect for urban environments and high-theft areas.

Advanced Components & Technology:

Features a keyed lock style for easy, reliable access. The Bulldog U-Lock is accompanied by a convenient mounting bracket for quick, secure attachment to your bike frame, making it ideal for everyday use. Plus, it comes with a 1-year anti-theft guarantee, demonstrating OnGuard's confidence in its durability and security features.

Stylish & Versatile Use Case:

Designed for commuters, city riders, and touring enthusiasts, the Bulldog Series U-Lock pairs strength with style. Its versatile 3.55-inch shackle width accommodates various frame sizes and locking points, providing flexible security options whether you're parking downtown or at a remote trailhead. The eye-catching black and yellow color combo enhances visibility, serving as a visual deterrent.

Key Features at a Glance:

- 13mm hardened ultra steel shackle for extreme cut and theft resistance

- Double bolt locking mechanism for unmatched security

- Reinforced sleeve over crossbar and cylinder adds extra protection against drilling and prying

- Includes mounting bracket for easy storage and transport

- 1-year anti-theft guarantee for peace of mind

- Dimensions: 3.5 x 5.5 inches; Weight: 2.3 lbs

Choose the OnGuard Bulldog Series U-Lock for reliable, high-security bike protection designed to withstand the toughest theft attempts. Perfect for urban cyclists, commuters, and adventure riders seeking peace of mind with stylish, durable bike security.

  • High-security U-lock featuring a 13mm hardened ultra steel shackle designed to resist cutting, drilling, and leverage attacks for maximum bike protection.
  • Engineered with X2P Double Bolt lock mechanisms and anti-pick, anti-drill technology, ensuring a robust and reliable locking solution for high-value bicycles.
  • Constructed from reinforced, forged steel with a durable black/yellow finish, this U-lock combines strength with visibility, making your bike less attractive to thieves and easy to locate.
  • Ideal for urban and high-theft risk environments, the 3.5 x 5.5-inch size offers versatile use cases, providing secure locking options for most bike frames and bike racks.
  • Includes a free 1-year anti-theft guarantee, along with a convenient mounting bracket for easy transportation, making this U-lock a must-have for serious cyclists seeking peace of mind.
Length5.5
Lock StyleKeyed
Cable IncludedNo
Shackle Width3.55
Advertised Weight2.3
Diameter13
Shipping
Returns
About Us
Contact Us

We pride ourselves on our ability to ship and deliver your gear with excessive speed! We ship from 22 locations throughout the United States and most orders will arrive in 3 days or less with Free Shipping on orders over $75!

The nitty gritty, for specific delivery timelines please pay attention to the delivery timelines on the product pages and the time frame estimated in the carts. If you need a part by a specific day, please contact us by chat, phone, or

Chat

Talk with a representative

Start Chat

Email

info@365cycles.com

Send Email

Phone

603-968-5797

Call Now

Most orders placed during the workweek before 1:00 PM Eastern time ship the same day, but during peak/holiday season or depending on inventory location handling time can take up to 48 hours. If you have questions regarding shipping estimates, don't hesitate to get in touch with us before placing the order. There is a direct signature requirement for all orders over $500.

We provide the you the ability to utilize multiple shipping & billing addresses, based upon what fits your current needs. However you are responsible to maintain and update any new address changes, as 365 Cycles will not be held liable for orders being shipped to an incorrect address.

  • Our Mistake: If we messed it up you can rest assured we are going to make it right. Contact us by email, phone, or chat and we will make your head spin with how quick we fix it
  • Warranty: We are an authorized retailer for everything we sell, so rest assured your product is covered under the manufacturer's warranty. Contact Us if you are having an issue and we will make sure you are taken care of
  • Just don't want it anymore: We have a 30-day return policy for orders within the US. We offer refunds on returned items that are brand new and in their undamaged, original packaging. Customers are responsible for the cost of return shipping. Damaged, installed, and used items as well as those without original packaging are not eligible for returns. If it's returned in this condition it may be denied and sent back to you

If you need to return your order please email us at info@365cycles.com, call us at 603-968-5797, or use the live chat on our site.

Chat

Talk with a representative

Start Chat

Email

info@365cycles.com

Send Email

Phone

603-968-5797

Call Now

*Please allow up to 3 business days for us to process your return*

365 Cycles puts the customer above everything. Our number one goal is your satisfaction. When you press the shift lever you want the gears to shift, and when you buy bicycle parts, you want the bicycle parts to arrive on time in new condition. With over 60,000 products and 22 warehouse locations throughout the country, we have the parts you need and they are coming in hot!

Living an active lifestyle is just that, a lifestyle that never goes away and our goal is to always exceed your expectations so we can take this lifelong journey together. We strive to have the parts you need, at competitive prices with unmatched shipping speeds!

If there is ever an issue with an order we will work at warp speed to fix our mistake and make sure you never go a day without a bicycle! If you are not receiving the quality of service you need from one of our exceptionally qualified bicycle experts, tell them Ben Berman told you to tell them "Customer Loyalty" and then name your terms.

Our team is waiting to help you 7 days a week and they are more qualified to help than I am but if you ever feel like you're not getting the service you need I’m personally asking you to email me at ben@365cycles.com with "CUSTOMER LOYALTY" in the title and I will personally handle your order.

Over the years we have served millions of satisfied customers and continue to serve many of them today. With your feedback, we are confident we can take this lifelong journey together and build a friendship that goes beyond parts and accessories.

“If you want to go fast, go alone, if you want to go far, go together.” -Someone Smart

Ben Berman Founder & CEO of 365 Cycles


Company Core Values: 

These were established by the members of our team and we use them every week to call out team members who have shined in one of these areas. Feel free to let us know at info@365cycles.com if someone you worked with has gone above and beyond in one of these areas. 

Customer Loyalty

Put yourself in their shoes and support those who support us.

You Control the Outcome

If it is to be, it’s up to me" You are personally responsible for controlling the outcome.

Seek Understanding

Understanding the answer is more important than the answer.

Progress Not Perfection

Pick a direction, analyze the results, and be willing to change course.

Will to Win

Customers, 365 Team, Partners, all need the will to win. Bring the Will to Win to every conversion.

Keep Moving

Move the body, move the mind, and remove any hurdles to achieving an active lifestyle.

Do the Right Thing:

Doing the right thing is more important than doing the thing right.

Stronger together:

If you want to go fast, go alone, if you want to go far, go together. Get your team involved and become stronger together.

Chat

Talk with a representative

Start Chat

Email

info@365cycles.com

Send Email

Phone

603-968-5797

Call Now

Customer Reviews

Based on 74 reviews
61%
(45)
30%
(22)
9%
(7)
0%
(0)
0%
(0)
V
Vertical

Happy with this lock. Got different sizes and all of them are good.;

R
Ruben

Muy buen candado seguro y con un adaptador para llevarlo con mucha comodidad. Yo lo estoy usando para mi motocicleta y me va genial.;

R
Rick Suk

This one is the perfect size for my bike locker at work. Smaller and lighter than the full size one that I need when I'm not going just to work.;

Z
Zoe

I now own 3 of these so my kids can lock their bikes too. My original is over 7 years old and works fine. Was even left outside in covered area for 2 years in Colorado weather.;

J
Juicy Dipa

Awesome lock love the size. fits into any bag or even my gal's purse/sling bag

we didn't use the bicycle holster but it looks and feels much more rigid than an EVO u lock holster - which flapped around endlessly.

the one concerning thing is that apparently there's some cancerous product/ingredient in this Lock and they warn that it could cause birth defects... anyone know where to store this safely? cus it's just sitting by our bikes in the apartment.;