Hi. I've just bought a Reebok Faith ladies mountain bike but after having cycled it I realised that the handle bars are too low. Could someone please tell me if I can raise them with a stem raiser. The stem and the bit that holds the handle bars seems to be all one piece. How do I get my handlebars raised? Do I need to buy a whole new stem + handlebars? I'm so confused, I only bought the bike to try to get fit and now I'm so uncomfortable on it I can't ride it. Someone please help.