If you just need a cheap and cheerful bike then the bike shop on the roundabout after the cube one going towards city centre, (sorry so vague), is really good. About 240QR for a brand new bike and they stock all the spares so if you need a new wheel etc it's only about 30QR.  My husband uses his every day and has had it for about a year. He also really likes the guys who work there, they are really helpful. Let me know if you want better diresctions. JJ