Shimano 105 has a 10-speed rear drivetrain, yet the complete group is lighter than the previous 9-speed version! One of the reasons is the HOLLOWTECH II crankset with integrated bottom bracket that combines weight saving with an increased rigidity for optimal power transfer. There is a Double and a Triple version but just one model of Dual Control Lever that is compatible with both front drivetrain options. Double front chainwheel combinations are 52-39 and 50-39. Triple combination will be 50-39-30. The cassette sprockets are all made of steel with an alloy sprocket carrier. Three combinations are available: 11-23, 12-25 and 12-27.
The Dual Control Levers feature the same ergonomical improvements as in Dura-Ace and Ultegra. The redesign allows a more comfortable position when riding with the hands on the rubber hoods. The arced shift travel makes sure that shifting is fast, smooth and ergonomic.
The Shimano 105 brakes also offer an improvement in function besides the design change. They feature an adjustable toe-in brake shoe and the brake cable mounting bolt is bigger than previous version for easier assembly and adjustment. The brake shoes are 100% more durable and they are 6.0mm thick (compared to 5.0mm in previous version). The hubs have been developed with an internal grease sleeve system and improved external seals and O-rings for improved rotation and sealing which increases service life tremendously.
New Shimano 105 offers the ultimate combination of function, design, weight and price for the sporty road racer who wants to improve his performance and have fun at the same time.