ICS3 is the third generation of Cervélo Internal Cable Stops (ICS). Other brands’ internal cables often run a liner or cable housing the entire length of the cables, adding friction and up to 200 grams of dead weight to your bike.
Internal Cable Stops on the other hand, function much like external stops. The housing fits into the stops and the bare cables travel in unobstructed paths through the frame, into the bottom bracket cable guide and straight to the derailleurs. Since ICS3 stops are a standard size, Rocket barrel adjusters can be installed so on-the-fly cable tension adjustments are easy and accessible.
ICS3 also incurs the least aerodynamic drag, by locating the cable housing entry out of the wind behind the stem. In order to have the cables enter the top tube yet travel unobstructed through the downtube, our ICS3 frames use Teflon lined stainless steel tubes, curved to guide the cables into perfect alignment with the Bottom Bracket cable guide.