I ride vintage racing bikes and yesterday I replaced the chain on my Medici Pro Strada. I only recently acquired this bike and by all appearances it is a very low mile bike with no rust. I noticed the rotten tires first thing and thought the bike had been sitting for a really long time , AND the grease in the bottom bracket had solidified. The anodized Mavic wheels had zero brake rub and the paint is very nice. After cleaning up the bike I was still not happy with the bike. Oh , it was a blast as far as handling and speed , but when I was in low gear , it felt rough as I really pedaled hard up the hills. The cogs were not worn and the chain rings were like new. I took it to my local bike shop yesterday and Mark put it on the stand and immediately suspected a worn out chain! He had a gage and it only took a few seconds. I chose the KMC chain as it was very close to the original width of the original chain. This is important when running 5 or 6 speed free wheels , too narrow and the chain will slip between gear changes( don’t ask me how I know ) . I am so stoked that Mark figured out the problem . I have never had a chain give this symptom before where it feels like the bearings in the BB are bad. Joe