New member here. I may have the opportunity to buy my neighbor's Specialized Tarmac; a big upgrade for me. I know he takes good care of his equipment, but I have concerns about buying a used carbon bike not knowing if carbon can fatigue over the miles. The bike has several thousand miles on it, mostly group rides and criteriums. It looks good and clean, but if there is no obvious damage to any part of the frame, should I worry that there could be any hidden damage or stress cracks?