Short answer: if your bike lives in a block-of-flats car park or a shared bike store, we'd fit a ground anchor into solid concrete and run a heavy chain through the frame and the anchor. The Kryptonite New York 1410 (100 cm, 4.9kg) is Sold Secure Diamond for ordinary bikes. Look for an anchor with its own Sold Secure approval, and get the building's permission before you drill.
Why a ground anchor matters in a shared car park
A lock is only as strong as what it's attached to. In plenty of block-of-flats car parks and shared stores, the only things to lock to are a drainpipe, a thin railing or a wobbly rack, and those can be cut or unbolted faster than a good lock.
A ground anchor gives you a fixed point you control. Bolted into concrete with fixings that can't be undone once fitted, it turns a parking space into somewhere you can lock to properly.
What to look for in a bike ground anchor
A grade. Some anchors have their own Sold Secure approval, and you can check one on Sold Secure's approved product search. We'd buy one that does, so the anchor isn't the weak link in a Diamond setup.
Fixings that can't be removed. Look for anchors that come with security bolts or are designed to be set in resin, so nobody can simply unscrew them.
Solid concrete underneath. An anchor in paving slabs or thin tarmac can be levered out. If you're not sure what the floor is, ask the building manager before you buy.
A loop that fits your chain. Check the opening is big enough for the chain you'll run through it. We don't review anchors ourselves yet, so read the maker's fitting instructions and the grade before you choose one.
Which chain to use with a ground anchor
This is where heavy chains make sense, because you don't carry them anywhere. The New York Fahgettaboudit 1410 is 100 cm of 14 mm chain at 4.9kg. The 1415 is 150 cm at 6.92kg, which is the one if you're locking two bikes or the anchor's a stretch away. Sold Secure lists both as Diamond for ordinary bikes and Gold for e-bikes.
Keep the chain off the floor if you can. A chain lying on concrete is easier to brace against for bolt croppers, so we'd pull it snug through the frame and anchor rather than leaving slack on the ground.
If the anchor sits close to where the bike parks, a long-shackle D-lock can work too. The OnGuard Pitbull LS 8002 has a 115 × 292 mm locking area.
If you rent or can't drill
You'll need the freeholder's or managing agent's permission to fix anything into a shared car park, and a landlord's say-so in a rented flat. It's worth asking, though. Some blocks already have anchors or secure stores you can use.
If you can't fit one, lock the frame to the most solid fixed thing you've got, and lock the frame to a wheel as well so the bike can't simply be wheeled off.
Locks for indoor storage in a flat without a garage
If the bike lives inside your flat, you mainly want it hard to wheel away from a shared hallway or communal store. A chain round the frame and a fixed point does that best. If the bike's inside your own front door, a D-lock through the frame and rear wheel is plenty, and it's the same lock you'll carry anyway.
For the lightest locks to keep in a small hallway, see compact bike locks for flats. For whether your insurer needs a particular grade at home, see best bike lock for insurance.
Chains to pair with an anchor
Kryptonite · Chain
Kryptonite New York 1410 chain
Diamond (ordinary bikes)
The 4.9kg weight makes this much more suitable for use at home than for a daily commute.
4.9kg · 100 cm · 14 mm
Kryptonite · Chain
Kryptonite New York Fahgettaboudit 1415 chain
Diamond (ordinary bikes)
At 6.92kg this is a chain to leave where the bike is stored. It is the longer option when 100 cm will not reach the post, the anchor, or a second bike.
6.92kg · 150 cm · 14 mm
Common questions
What's the best way to lock a bike in a block of flats car park?
A ground anchor fixed into solid concrete, with a heavy chain such as the New York 1410 running through the frame and anchor. Get the building's permission first, and pick an anchor with its own Sold Secure approval.
Can I fit a ground anchor in a rented flat or shared car park?
Only with permission from the landlord, freeholder or managing agent. Ask, because some blocks will agree or already have secure stores.
Do I need a Diamond chain at home?
If your insurer names Diamond for home storage, yes. The New York 1410 and 1415 are Diamond for ordinary bikes and Gold for e-bikes. Check what your policy says.
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