I’m finally investing in keeping my bike really safe - this diamond-rated and angle grinder-resistant bike lock is down $53 for Cyber Monday

The thing I find most stressful about cycling isn’t the traffic (though that’s a close second), it isn’t having the right kit or the slickest bike set-up - it’s locking my bike up to grab a quick end-of-ride coffee, or to nip into a shop, and having it stolen.

I have a collection of locks: two d-locks, one combination lock that I keep wrapped around my handlebars for short absences only, and a small chain lock. But the most I’ve ever spent on one is £40 - I’m loath to spend money on bike locks, the sense of injustice at having to invest in kit to guard against another person’s decision to nick my lovely bike too strong. But I really should.

And now this OnGuard RockSolid D-Lock is on sale for £50 off in the UK from £199.99 and $53.99 in the US, down from $269.95 - and I’m finally investing in keeping my bike really safe.

‘The OnGuard RockSolid is virtually impervious to the cutting force of angle grinders,’ reads the product description on Tredz. Rated sold secure diamond, the lock is secured at four separate points to ensure maximum security and made of steel. It’s ‘massive and robust’ but finished with a rubber coat to protect your bike from scratches sustained from the lock’s interaction with the frame. It’s so strong that it’s used on motorbikes, too.

Save 20% ($54)

OnGuard Rock Solid: was $269.96 now $215.96 at Amazon

This angle grinder resistant lock also comes with five keys.

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Save 25% (£50)

OnGuard Rock Solid: was £199.99 now £149.99 at Tredz Limited

This lightweight, ultra-secure bike lock is one of our favourites - sturdy, strong and equipped with internal multiple locking systems that can help guard against angle grinders.

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It also scored a five-star rating from our Cycling Weekly reviewers, who hailed it: “light, affordable and possibly the most secure lock on the market.” It’s its lightness that really appeals to me too. The uniform of many cyclists I see pedalling around London seems to be: a pair of wide trousers, a little beanie and a bike lock hanging off a belt-loop. How their trousers don’t get tugged down from the weight of their d-lock so effortlessly attached boggles my mind. This d-lock might just be my ticket to the cool-club - light enough to cart around without the need of a bag, but strong enough to guard against theft. Hallelujah.

To check out other locks on great deals today, visit our best lightweight bike locks 2025 hub page. But if you’re looking for more Christmas bargains for yourself or your friends and family that are a little more glamorous than the humble bike lock, head over to our Cyber Monday cycling deals page now!