Yes, that's exactly what they are.They look like reminders of the Paris Roubaix pavé sectors. Distance from the start in the left column, length of cobbles on the right.
No matter, only the rider who wrote them has to read it. Seems a strange place to see this stuff on top tube, as in first picture. Much better in this one easier to read. before GPS and all that stuff it's how we always worked, notes on stem and watch the blackboard. Simpler days....no DS could witter away in your ear all day!They're not always that neat and tidy.
Most of the pics I have seen show that most riders still have the info on the stem; the one in the OP is from Etixx-Quick Step and seems a bit larger than most. I have not been able to work out the relevance of the sections surrounded by red. They are not the 4* and 5* sections, which I thought they might have been.No matter, only the rider who wrote them has to read it. Seems a strange place to see this stuff on top tube, as in first picture. Much better in this one easier to read. before GPS and all that stuff it's how we always worked, notes on stem and watch the blackboard. Simpler days....no DS could witter away in your ear all day!