Smoother is faster. The more comfortable and less fatigued you are at the end of a 4-hour ride, the stronger you'll be. Like shocks on a race car, the Zertz vibration damping inserts on the Roubaix SL4 help absorb road impact and keep power planted firmly on the road couple that with a FACT carbon 8r frame and it's still plenty stiff to thrash around in a sprint.
The Specialized Roubaix SL4 Sport 2015 Features are:
Frame: Specialized SL4 FACT 8r carbon, 1-1/8" to 1-3/8" headtube, compact race design, Zertz, internal rear brake cable, OSBB
Headset: 1-1/8" upper, 1-3/8" lower, Cr-Mo cartridge bearings, 20mm cone spacer, w/ 20mm of spacers
Bars: Specialized Comp, shallow drop, 6061 alloy, 125mm drop, 70mm reach
Stem: Specialized Comp Multi, 3D forged alloy, 4-bolt, 12-degree rise, anti-corrosion hardware
Speed: 22
Front Mech: Shimano 105
Rear Mech: Shimano 105, 11-speed, long cage
Shifters Shimano 105 STI, 11-speed
Chainset: FSA Gossamer, BB30
Cassette: Shimano 105, 11-speed, 11-32
Chain: Shimano 105, 11-speed
Front Brake: AXIS 1.0
Rear Brake: AXIS 1.0
Rims: AXIS 2.0
Front Hub: AXIS 2.0
Rear Hub: AXIS 2.0
Spokes: AXIS 2.0
Tyres: Specialized Espoir Elite, 60TPI, folding bead, double BlackBelt protection, 700x25c Front Specialized Espoir Elite, 60TPI, folding bead, double BlackBelt protection, 700x25c Rear
Seatpost: Specialized CG-R, FACT carbon, single bolt, 27.2mm