Tom Boonen, QuickStep, debut new Specialized Roubaix SL4

New Specialized S-Works Roubaix cobbles bike under select riders this weekend

James Huang/Future Publishing

Published: April 6, 2012 at 3:00 pm

Tom Boonen, Sylvain Chavanel and other members of Omega Pharma-QuickStep will tackle the cobbles of Paris-Roubaix aboard a new bike from team sponsors Specialized. The bike doesn't officially have a name yet, but past convention tells us this will be the next-generation S-Works Roubaix SL4.

Specialized wouldn't divulge details of the new bike, as it's still in the final stages of development. Per UCI rules, bikes not only have to meet the governing body's testing process but they also "have to be presented to the media" so we were shown the new bike but weren't given any details.

The seat stays switch to a new open-back shape that now houses bigger zertz dampers: - James Huang/Future Publishing

The seatstays now house bigger Zertz dampers

Still, visual inspection shows several key changes, most notably yet another evolution of the company's distinctive Zertz viscoelastic dampers inserted into the fork blades and seatstays. They're not only bigger than ever but also plug into new pockets in the frame that maximize surface area contact to more effectively damp vibration. Specialized wouldn't disclose the reasoning behind the new shape but we presume it lends more comfort than the current Roubaix SL3.

Specifics regarding tested frame stiffness figures and claimed frame and fork weights were also unavailable at press time, but the tapered steerer retains the current 1-1/8 to 1-3/8in diameters. Tom Boonen’s personal Roubaix SL4 prototype weighed 7.53kg (16.6lb) on our scale.

The uci require that boonen's new roubaix sl4 be shown to the press before he can race it, so on the penultimate eave of paris-roubaix, specialized held an impromptu unveiling: the uci require that boonen's new roubaix sl4 be shown to the press before he can race it, so on the penultimate eave of paris-roubaix, specialized held an impromptu unveiling - James Huang/Future Publishing

The UCI require that Specialized show Boonen's new Roubaix SL4 to the press before he can race it, so on the eve of Paris-Roubaix they held an impromptu unveiling

More information is expected later this summer, but Specialized brand communications manager Ben Delaney told BikeRadar that the new bike will be "available in very limited quantities in the fall". Specialized say Boonen – as well as new teammate Zdenek Stybar – began testing the new bike on the cobbles late February in Mol, Belgium.

Along with the new chassis, Specialized have a new complementary seatpost concept. Currently referred to as the COBL GOBL-R, Specialized director of advanced development Chris D'Aluisio says it "doubles the compliance" of the Roubaix on its own, but is still stiff enough that it doesn't actually feel like it's moving under normal riding conditions.

Specialized says tom boonen (omega pharma-quickstep) has already tested this novel suspension seatpost but decided to play it safe on race day. specialized unofficially calls this the 'cobl gobl-r': - James Huang/Future Publishing

Specialized say Tom Boonen (Omega Pharma-QuickStep) has tested this novel suspension seatpost but decided to play it safe on race day. It's unofficially called the 'COBL GOBL-R'

Moreover, D'Aluisio says most of the motion of the Roubaix frame itself is fore-aft and Specialized are reaching the limit of how much movement is available. On the other hand, the COBL GOBL-R's motion is mostly up and down and since it only moves on bigger hits, riders apparently aren't bothered by the subtle (and momentary) change in saddle height. Claimed weight for the carbon fiber COBL GOBL-R is 230g.

This season Boonen debuted some significant changes to his personal position after a fit session with Specialized SBCU director Scott Holz. His saddle height is now up a full centimeter, bar width is down from 46cm to 44cm, and tweaks have been made to his shoe insoles, which have, supposedly, improved his pedal stroke.

Overall, Specialized claim the modifications (especially the change in bar width) save Boonen 20 watts of energy at cruising speed and his sprinting style is now significantly more stable and lower up front. It obviously worked in Flanders, and this weekend will likely be total proof of concept for the new Roubaix, and Boonen’s new position.