Although this is an older bike (1987), I would like the extensive knowledge of present bike owners to take a look at this picture. Is there a vertical crack on my down tube? I cannot feel a fissure when I run my finger across or down it. If it's a crack- what do I do? This is my first real road bike and it's treated me so well- I've put over 200 miles on it (more than my lifetime, haha), and I love this bike.