What does it mean to have rib pains after a small motorcycle accident?

Pain. Maybe due to bruise or rib fractures. If the rib fractures were serious, you would have sought immediate attention.
Small rib fx. Probably a rib fracture, x-ray are usually not diagnostic an treatment is conservative.
Sell the bike! It could be bruising of the chest wall or rib fractures. See your doctor. Let him examine you. He might want to get x-rays.