To the test: The new Lapierre Pulsium takes on the brutally rough roads of Paris-Roubaix.

Okay, that headline might be a little bit of a stretch. But with the release of the Pulsium in winter 2014, France's Lapierre will join the growing number of bike makers producing endurance road models with some sort of tangible rear end bump absorption. (See: Domane, Trek; Roubaix, Specialized)

In the case of the Pulsium, rough tarmac taming comes courtesy of an elastomer insert that's integrated into the lower half of the bike's unique-looking y-shaped top tube. The new steed made its international debut at Europe's punishing cobbled classics, where it was raced by the FDJ team. Look close at the photo above and you can see it at work at last Sunday's Paris-Roubaix.

We got an in-person look at the Sea Otter Classic, and while lots of key details are scarce (price, spec, exact availability timeline), Lapierre representatives said the insert provides up to 3.5mm of vertical flex, or 27 percent more than Lapierre's existing endurance models. Test rides were not available, so for now we'll have to take them at their word.



Elongated: The Pulsium has a longer wheel base than previous models thanks to increase fork offset and lengthened chainstays.

Other noteworthy features include a fork offset that jumped from 43mm to 50mm for increased front-end flex, a longer, ride-smoothing wheel base, a more complaint 27.2mm seat post, and a modular rear brake caliper that plays nice with long reach brakes, meaning you can run tires up to 32mm wide. There's also an internal housing inside the top tube, which helps abate cable rattle on rough roads, and an integrated seat post clamp for increased aero efficiency.



Bump absorber: This elastomer insert is claimed to provide 3.5mm of vertical bump absorption.

Exact geometry figures were not available, but the Lapierre folks say the Pulsium has longer chain stays (4mm longer than Xelius EFI, same length as Sensium) for increased stability at speed and better shock absorption, and a longer head tube (15mm longer than Xelius EFI, 5mm longer than Sensium) for a more upright riding position.



Power box: The Pulsium utilizes the standard lay-out for endurance road bikes, stiff and strong down low, complaint and comfortable up top.

Carried over from previous models is what Lapierre calls Power Box, where head tube, down tube, bottom bracket and chainstays are all oversized and reinforced with higher modulus carbon, while the bike's top floor is more forgiving.

As for initial results, FDJ had a solid day at this past weekend's Paris-Roubaix, placing a rider in the opening break, and scoring 12th place thanks to Arnaud Demare.