Which U-lock suits your bike and parking spot
A longer lock isn't automatically more practical: compare the lock's opening with the frame, wheel and racks you actually use.
Choose a U-lock based on the rack and the parts of the bike you lock. Look at the rack outside your office, building or university and measure the distance from the frame tube to the point you lock it to.
The compact model with a 230 × 110 mm inner opening takes up less space in a bag and works well with standard city racks. It won't span a wide post or every frame together with the wheel.
The extended 300 × 115 mm model gives more room for a bulkier frame or a poorly placed rack. It's also harder to stow and leaves more free space inside the locked loop.
Also decide where you'll carry the lock: in a backpack, a handlebar bag or on a frame mount. On a small frame, the mount can interfere with the bottle, cables or your knee, so check the position before fitting.
- Measure the widest part of the frame that goes into the opening.
- Measure the distance to your usual rack.
- Only add space for parts you actually lock together.
- Check where you'll carry the lock while riding.
For longer parking, choose a visible, busy spot and lock the frame to a solid fixed point. No lock fully prevents theft.