Tresor 6615C Combo SCMU

The ABUS Tresor 6615C Combo SCMU is an 85 cm Steel-O-Flex combination lock: a steel cable inside overlapping 15 mm steel sleeves, with a code you set yourself and a tool-free SCMU frame bracket. The ABUS Tresor 6615C weighs 705 g and suits entry-level and kids' bikes at low theft risk.

How secure it actually is

Steel-O-Flex is ABUS's halfway house between a plain cable and a chain. Rows of overlapping steel shells sit over the cable, so a thief has to get through hardened sleeves before reaching the wire, while the lock still bends round a post like a cable does. The Tresor 6615C is built for low-risk spots: the school bike rack, the kids' bikes outside the shop, a café stop with the bike in view. The combination mechanism carries ABUS's touch protection, which makes it harder to feel your way to the code by working the dials.

Weight against security

At 705 g it is heavier than a skinny cable and a lot lighter than a chain, and the bracket carries it on the frame, so it comes along on every ride rather than sitting in the shed. For a bike left all day in the city, pair it with a D-lock.

What it locks to

85 cm is a neat length for a frame to a bike rack, a sign post or a railing, or two kids' bikes threaded together. A plastic coating over the sleeves keeps the steel off your paintwork where the lock rests on the frame.

Keys and mounting

• No keys at all. Choose your own code, and the whole family can share the one lock.
• Readable by feel. Dark-touch imprinting on the moulded digits lets you set the code after dark, and two-component number reels stay legible as the lock ages.
• SCMU bracket included. It straps to a seat post, frame tube or rack stay 15–55 mm across, with no tools, and the lock clicks in and out.

Looking after it

Rinse dust and grit off the number reels after a wet or dusty ride and spin them through now and then so they keep turning freely. Write your code down somewhere safe at home before you need it.