The back brake on my bike is not functional, is it illegal for me to cycle in the United Kingdom?
Yes, technically.

Most sorts of cycle are required to have at least two efficient braking systems, by which the front wheel (or wheels) can be braked independently of the rear wheel (or wheels).


The likelihood of you receiving a ticket, fine, or other punishment is infinitesimal. It could happen, but it almost certainly will not.

Practically, the front brake is much stronger than the rear brake. Most experienced road cyclists almost exclusively use the front brake. Why is it &quot;a bit difficult to stop&quot; in some circumstances?

That said, you should absolutely have it fixed. Having redundant brakes is important for your personal safety. Brakes and brake cables can fail.