ShimanoROAD on Twitter: "Already 10 years ago we introduced the Shimano Ultegra 6600 10-speed group set! #ThrowbackThursday http://t.co/LrI0punwvk" / Twitter
Should I upgrade Ultegra 6600 to 105? : r/cycling
Shimano Ultegra 6600 10 speed compact groupset (same era as Dura ace 7800), Sports Equipment, Bicycles & Parts, Parts & Accessories on Carousell
Shimano Ultegra 6600 10 Speed Double Chainset - Silver (FC-6600) for sale online | eBay