I got a 2010 kona hei hei 100. I bought it brand new as a two year old left over for 40% off. It has 1200km or 750 miles on it so far. My goal is to have 2000km or 1250 miles on it by the end of the year. Now that some things that were preventing me from riding are sold. At what point do you consider a bike worn out and time to buy a new one?