Originally Posted by
Monoborracho
What is the difference in 6500 vs. 6510?
Shimano just upgraded their nine speed Ultegra set over the years. First came the 6500, then the 6501, then finally the 6510 (2007). They all look slightly different cosmetically. I have 6501s on my two main riders.
If I was buying NOS nine speed Ultegra, I would definitely go for the 6510. In fact, that deal is so good on Chain Reaction, I might buy a set as backup (pretty much all Shimano brifters die eventually).