How to choose a bike lock

What Sold Secure Gold and Diamond mean

Sold Secure is the UK group that tests bike locks. Locks are graded Bronze, Silver, Gold, and Diamond. Gold is still what a lot of household cycle insurance asks for. Diamond is the next step up. Neither grade means the lock cannot be cut. Diamond is tested against a tougher set of tools than Gold. It is not a promise that a thief with a battery grinder will walk away.

There is a separate Sold Secure test for e-bikes. A lock can be Diamond for an ordinary bike and only Gold for an e-bike. That split matters if your policy names the e-bike grade. The ABUS Granit XPlus 540 is the example on these pages: Diamond for ordinary bikes, Gold for e-bikes.

Treat lines such as “20× more resistant” as advertising unless an independent grade is marked on the lock. If you are shopping locks sold against angle grinders, read what to look for in an anti-grinder bike lock. After this page, read best bike lock for insurance. We do not keep a live list of which insurers accept which models. Those lists change, and we are not selling you a policy.

The cable in the box is usually not graded

Plenty of Gold D-locks come with a loop cable. On Kryptonite’s Evolution Mini-7, that cable is not part of the Sold Secure approval. Use it to hold a quick-release front wheel to the frame if you need to. Do not treat it as a second Gold lock, and do not lock the bike to the stand with the cable alone.

If a product photo makes the whole kit look approved, ignore the photo. The D-lock is the graded product. The cable is a useful extra.

Will the lock close on your stand?

A compact D-lock that will not close around the stand does not protect the bike. The figure that matters is the locking area: the space inside the shackle. Compare that with the post plus the tube of your frame. Measuring the stand is more useful than choosing by brand.

Longer shackles close more easily. The ABUS Granit XPlus 540 here is 300 mm; the OnGuard Pitbull LS is 115 × 292 mm. Both will take posts that a Mini cannot. The trade-off is extra room for a thief’s tool. Tight Minis — the Hiplok D1000 is 92 × 155 mm — are awkward on fat tyres, cargo frames, and some UK street furniture. The Hiplok DX1000 (112 × 205 mm) is the larger Hiplok if that compact hole is the problem. If you already know a compact lock fails on your rack, look at the LS, the 540, the Bordo 6500K if Gold and folding reach will do, or a chain you leave at home.

Will you actually carry it?

The lock you leave at home does not protect the bike at the station. Weight, and whether it clips to the frame, decide whether you take it every day.

Among the locks we reviewed, the lightest Diamond D-lock is the Seatylock Mason 140 at about 0.97kg (mount sold separately). The clipped options sit next — the Pitbull STD at 1.44kg and the Evolution Mini-7 at 1.61kg — while bag-carry Diamond locks such as the Litelok X1 (1.7kg) and the D1000 (1.93kg) run heavier, and the Bordo 6500K, DX1000, and New York 1410 chain climb from 2.47kg up to 4.9kg. If 1.6kg already feels like too much, a 2kg lock with a tougher-sounding name will not help.

A lock that clips to the frame is the one you are most likely to have with you every morning. If the box does not include a clip, budget for one, or be honest that you will carry it in a bag.

D-lock or chain

A D-lock — sometimes sold as a U-lock — is for a tight stand on a commute. A chain is for extra reach: home, a ground anchor, two bikes, or a post a compact D-lock cannot close around. A folding lock sits between those jobs: the Bordo 6500K is Sold Secure Gold, 120 cm, with an SH bracket, when you need Mini-7 grade and more reach than a rigid shackle, on the bike. D-lock vs chain is the longer comparison.

Many careful riders use both, and only carry the D-lock. That is a practical setup: Gold or Diamond on the bike for the station, and a heavy chain left where the bike is stored overnight. A 4.9kg chain is too heavy for a daily commute. Most people will stop carrying it after a few days.

How to lock the bike

Lock the frame to the stand. If the shackle will also take the rear wheel, do that. Do not lock a quick-release wheel to the stand and leave the frame free — the rest of the bike walks away.

Fill the shackle as much as you reasonably can. Slack in a D-lock or a chain gives a thief room to get a tool in. Check the stand itself is bolted down. A Gold lock on a loose hoop is only as good as the hoop.

At home, lock through the frame to something that does not move — a ground anchor if the policy asks for one, not a wooden fence post. Looping a chain twice can take up slack. It does not change the Sold Secure grade, and it does not turn a lamp-post into an approved anchor.

Which specs you can ignore

• Anti-grinder marketing matters less if you park in sight for ten minutes and Gold already meets the policy. Carry the compact D-lock.
• Compact “Mini” locks will not close on every fat lamp-post. Measure, then look at the Pitbull LS, the ABUS 540, the Bordo 6500K if Gold is enough, or a chain at home.
• E-bike Diamond is unnecessary if you ride an ordinary bike and the policy only names Gold.
• A 4.9kg chain is much more suitable for use at home than for a daily commute.

Common mistakes

• Locking a wheel and leaving the frame open. The frame is what you need to take home. A quick-release wheel is replaceable; the bike is not.
• Trusting the cable as if it were Gold. The cable is usually ungraded. Use it for a wheel, not as the lock.
• Buying Diamond, then leaving it at home. A Gold lock you take with you protects the bike. A Diamond lock left at home does not.
• Never checking the insurer’s approved-lock list. A Sold Secure badge is required on many policies. Being on that insurer’s list is a separate check.