My daughter went out on her bike last night. Before she went she got me to check her bike over and pump up the tyres. When she got back I asked her how she got on. She said she had just ridden around the estate for a bit until she got bored. Then I had a look at the ride stats on her computer. She rode 8 miles in just over half an hour at an average of 15mph. Not bad for a 13 year old on a mountain bike!