I've just bought a bike from them and had a tour around their warehouse in South Yorkshire. They have boxes full of spare parts. They can repair most stuff while you wait http://www.oxygenbicycles.com/contact-us
I've just bought an Oxygen S-Cross CB and it's great. I hear rumours that there might be a way to disable the 15.5mph limiter. Anyone know anything about that? Sorry if I'm not allowed to ask that on here...