For those who want excellent protection against bike theft but who live in a relatively low-risk area, this lock provides a nice balance of convenience and security.
Lightweight and compact. Although the Bulldog Mini TC isn't as strong or durable as the U-locks in OnGuard's top-of-the-line Brute series or Kryptonite's New York series, it's very lightweight and inexpensive.
At less than 2 pounds, the Bulldog Mini is highly portable and light enough to throw in a bag or backpack, although a mounting bracket is included. Reviewers say it's a top pick for convenience, but warn against using it in a high-crime area. As with most other U-locks, users should consider an additional level of protection for a bike's seat and front wheel. While the Bulldog Mini TC can loop around the anchor location and frame, you need an additional cable or chain to secure the front wheel.
Not the toughest. At 13 mm, the OnGuard Bulldog Mini TC's shackle isn't the thickest on the market; the leading Kryptonite New York Fahgettaboudit Mini (Est. $70) measures 18 mm. Still, the hardened steel shackle and interior size of about 3.5 by 5.5 inches provides enough protection to deter attacks from bolt cutters and hacksaws. Reviewers add that the small interior size gives thieves little leverage. For beefier frames, the OnGuard Bulldog Mini LS 5013TC (Est. $30) is 1.5 inches longer. On the downside, some owners say the lock begins to rust after being exposed to moisture.
Low anti-theft protection. Most tests using common tools carried by bike thieves find that the OnGuard Bulldog Mini TC holds its own against a bolt cutter. However, this lock can succumb to a hacksaw given enough time, and an angle grinder makes easy work of it. As always, riders should take care to lock their bikes in highly trafficked areas. The Mini TC has an anti-theft protection offer of $1,500, but it isn't available in New York where bike theft is a major problem. It also comes with five laser-cut keys, one with a built-in light, and a mounting bracket.
Review Credibility: Very Good Rossiter tests the LS version of the Bulldog Mini, which is slightly longer but otherwise identical. "At this price, the Bulldog Mini is one of the best mini U-locks out there," he says. He couldn't break it with conventional tools, but it was cut with a power tool.
Review: OnGuard Bulldog Mini LS Lock Review, Warren Rossiter, Feb. 5, 2009
Review Credibility: Good About 20 posters review the OnGuard Bulldog Mini TC at Buzzillions.com, giving it 3.9 stars out of 5. Owners like the lightweight design, but say the lock is prone to rusting. One user gives it just 1 star because of the mounting bracket's design. However, another says that at least two attempts by thieves to break this lock have been unsuccessful and it can absolutely be trusted.
Review: OnGuard Bulldog Mini 5013TC Bike U-Lock, Contributors to Buzzillions.com, As of May 2013
Review Credibility: Good The OnGuard Bulldog Mini TC gets 3.7 stars out of 5 from nearly 40 owners at Amazon.com. They say it's very sturdy and durable, and call it a great choice for commuters. While this version isn't currently available here, there are other OnGuard Bulldog Mini options.
Review: OnGuard Bulldog Mini TC 5013TC Bicycle U-lock, Contributors to Amazon.com, As of May 2013
Review Credibility: Fair Here the OnGuard Bulldog Mini TC is appreciated for its light weight and small size, but its size also limits what you can lock it to.
Review: Review: OnGuard Bulldog Mini TC Bike Lock, "Dave", June 24, 2009