I know there has been thousands of posts on which are the best bike locks but i still haven't been able to identify a lock I need. I have a Boardman Road Comp (RRP £650) and I need a decent lock. I'm not planning to lock it over night but i do need to lock it up during the day. Everyone says that the Kryptonite NY is the best but it is also Expensive. I usually lock my bike to a railing or a lamp post so i need the lock to be large enough to fit around there. I would like it to be relatively light and portable. The maximum I'd be willing to spend is around £40. Lastly small D-locks are said to be hard to break but they are very small so can't be fixed to many things would it be worth using one as a padlock atttached to an extension cable?