I borrowed a friends mountain bike to do a mountain bike triathlon (I was planning on using my hybrid, but I'm not sure it is beefy enough). To make a long story short, she lent/gave me her bike, but she has not used it in at least a year - but she did have it tuned up before she basically stored it. It looks like it is in decent shape, I put air in the tires and they seem to be ok, but the back wheel is making a very loud click click click click when I am riding. Is this normal? Is there anything I can do to give it a quick tune up? I will bring it in and have it done by a bike shop, but I will never be able to get it in before the race on Saturday because there is at least a week to two week wait at my local bike shops. So, should I risk using it, or should I attempt the course on my hybrid (NOT a beefy hybrid!), or should I bag this race? Thanks!