ABUS Granit XPlus 540 U-Lock

Apple AirTag (with hidden bike mount)

Best for: iPhone owners · Urban and suburban parking · Pairing with a good lock

Kryptonite New York Fahgettaboudit Mini U-Lock

This is the lock to buy when the bike costs more than the rent. The Fahgettaboudit Mini uses an 18 mm hardened steel shackle with a double-deadbolt crossbar, which puts it in the small group of locks that shrug off bolt cutters and force attackers to use a grinder and time. The mini shackle is deliberately small so there is little room to fit a jack or pry bar. The trade-off is that small opening: you will not lock both frame and wheel to a fat pole with it, and it is heavy enough that many owners leave it at the office rack and carry something lighter for quick stops.

Best for: High-value e-bikes locked outdoors · Urban and campus parking with theft pressure · Riders who leave the bike in one spot all day

ABUS Bordo Granit XPlus 6500 Folding Lock

Folding locks solve the problem U-locks have on e-bikes: fat tubes, rear racks and awkward parking posts. The Bordo 6500 uses thick hardened-steel links with protected rivets, packs into a holster that bolts to bottle bosses or straps to the frame, and opens wide enough to wrap a wheel, frame and pole together. It is among the strongest folding locks tested, though any folding design still gives up some security to a good 18 mm U-lock at the rivets. For e-bikes parked during the workday or at a campus rack, the combination of reach and carry convenience is why it sells so well.

Best for: E-bikes with fat tubes that U-locks cannot reach around · Commuters who want a lock that lives on the frame · Locking to odd-shaped racks and posts