Myself and a friend are looking to start mountain biking. The main reason we would like to start i so we can enter adventure races that generally have a mountain biking leg to the the race. So we looking for advice on what bike to buy (what should we be looking at) and where to buy. We only look to use the bikes maybe twice a week... once to train and once to race. That being said we dont want to spend a fortune but just need to know that what we buy will be suitable... if it means spending an extra grand for something MUCH better then we would do so.... Thanks