Shimano Road Tandem cranksets have Ultegra level hollow forged crank arms, reducing crank arm weight without compromising strength and rigidity. R601/R603
Hyperdrive SG-X chainrings Dual SIS front index shifting Bottom Bracket Included Spindle Interface Type: Hollowtech II Chain Compatibility: Shimano 10 Pedal Spindle: 9/16" Crank Intended Use: Tandem