My 16 yr old nephew is a STRONG rider. 130 pounds of muscle and endurance, training for tri events (and winning many) in Ontario.
He is a bit hard on equipment though and has chipped the top tube on his LOOK CF bike down to but not into the fibre. about half the size of your little finger nail.
Can you apply epoxy or fibreglass resin on the wound or is smoothing the roughness off with FINE wet/dry paper good enough?