Wiki Bicycle » Shimano » SW-7971
Information from: www.shimano.com.
Dura-Ace Di2 TT Extension Shifter Set. Designed exclusively for triathletes and time trialists, the new system eliminates the need to change hand positions during shifting. Riders can change gears at the base bar (ST-7971) as well as the bar extensions (SW-7971) because the system in linked.
Features