KneesUp
Guru
I replaced my Aldi lock with one of these (£24) http://www.halfords.com/cycling/acc...ortum-gold-sold-secure-d-lock-210x110mm-black
It's 'Gold Secure' - however it turns out that a U lock on a mountain bike isn't big enough to get around the seat tube, the rear wheel, the front wheel (removed) and a post - which is how I used to use one with my road bike. So I have some chunky chain (actually chain from a reduced bike lock in tesco that had a rubbish looking padlock) that fits on to the u lock to use when I am leaving the bike for a while - otherwise I lock the frame with the u lock and leave the wheels to chance.
It's 'Gold Secure' - however it turns out that a U lock on a mountain bike isn't big enough to get around the seat tube, the rear wheel, the front wheel (removed) and a post - which is how I used to use one with my road bike. So I have some chunky chain (actually chain from a reduced bike lock in tesco that had a rubbish looking padlock) that fits on to the u lock to use when I am leaving the bike for a while - otherwise I lock the frame with the u lock and leave the wheels to chance.