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Roubaix Pro Bike Tech: Lapierre Pulsium slips in new elastomer enhanced endurance race bike for the pavé

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At an FDJ team introduction ahead of this weekend’s Paris-Roubaix, French bike maker Lapierre unveiled their new Pulsium endurance road bike that the team will ride to take on the brutal pavé of the cobbled Spring Classic this coming weekend. The bike was designed with rough road racing in mind, and takes the basic SAT elastomer suspension concept from the previous generation Pulsium and updates it to a level of lightweight race-ready performance previously reserved for the Xelius SL race bike range. We found the bike lurking in the back of the team truck and on the roof of a team car to get a closer look…

studio photos courtesy of Lapierre

Lapierre and FDJ worked closely on the new Pulsium on the difficult task of finding the best balance between the contradictory concepts of comfort and stiffness that define an endurance race bike, the ultimate goal being to reduce rider fatigue and soak up enough vibration to keep the wheels firmly planted to the road for effective power transfer on even the most extreme surfaces.

Lapierre like to say that FDJ keep them on their feet. And while French road teams have a bit of a reputation for being resistant to change, FDJ has been a team that has shown a lot of interest in new tech, developing & testing bike with Lapierre but also working with Shimano to develop new groupsets and especially the new Dura-Ace power meter crankset.

The heart of the bike is a simplified 1-piece SAT (Shock Absorption Technology) elastomer that interrupts the extended seatstays between the seattube and the top tube. The Xelius uses a similar looking frame profile that extends the seatstays around the seattube without touching it to allow for flex & vibration damping in the stays. However the Pulsium connects the seatstays directly to the seattube in a more conventional fashion, but allows flex around the seat cluster where the front & rear triangles can move independently enough to soak up even larger impacts and vibrations.

The new bike now meets the performance needs of the top-level professional racers with much improved lateral stiffness, while still delivering the vibration damping character that will help them reach the velodrome finish fresh enough to contest the final sprint. FDJ will race the new bike in this model year 2018 Pulsium Ultimate FDJ tricolore paint scheme with fully chromed out logos.

Like many of the modern crop of endurance race bikes, the new Pulsium gets relatively slender seatstays & toptube, that are then complemented by a massive downtube, BB & chainstays (what Lapierre calls Powerbox tech) to deliver efficient power transfer. The bike also includes an updated fork and steepened headtube angle that doesn’t seem to offer much more in the way of comfort, but does reduce lateral flex for improved tracking on rough terrain and more race-ready offset for responsive steering. It also gets Lapierre’s modular internal routing & recent Di2 battery trap door to get the bike weight low (and easy to access) at the BB.

The new Pulsium for now has been shown in a single bolt, rim brake only version for the FDJ team, but we anticipate that a new disc brake version could be close on its heels, possibly as early as this summer.

LapierreBikes.com

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Bingo
Bingo
5 years ago

nice slot at the bottom bracket for easy battery removal and replacement

Flamme Rouge
Flamme Rouge
5 years ago

Maximum tire size?

edge
edge
5 years ago

this does not isolate the seat-post like Trek’s does, so how is the seat-post supposed to move without the rear triangle moving?

Papi
Papi
5 years ago
Reply to  edge

Yeah, I’m confused by this design as well. So the top tube is attached to the seat tube (white portion) above the elastomer, and the seatstays are attached to the seat tube behind the elastomer. How exactly is the elastomer working? It looks like it’s just along for the ride. Explain yourselves, Frenchies.

Andrew
Andrew
5 years ago
Reply to  Papi

Agreed! This makes zero sense in my head….

TheKaiser
TheKaiser
5 years ago
Reply to  Papi

Agreed that it looks like it does very little. They might intend the seat clamp area with the little bridge to the top tube to function as a flex pivot version of Trek’s actual mechanical pivot. Then, under load, the seat post and clamp area would flex down and back, and the lower part of the seat tube where the stays come in could flex forward and up into the elastomer. Even still, I don’t think it would do much, just as with the Specialized Zerts, which Spz seems to have acknowledged in that they haven’t included them on the new Roubaix. Lapierre would be better off ditching the extended seat tube and putting on a longer flexier post to accomplish the same purpose in a more efficient and effective manner.

J D
J D
5 years ago
Reply to  Papi

Patent limitations?

Josh
Josh
5 years ago

And it is non replaceable. We all know an elastomer does not last forever. I guess that is why LP bikes only have a 5 year warranty. That thing will start turning into a hard dried out brick after 5 years.

ascarlarkinyar
ascarlarkinyar
5 years ago

This design is to reduce vibration, not do shock absorption. Problem is the design ahead of the locked in seatpost also cannot react fast enough to take off pave chatter. So it’s more of a looks cool more than works cool thing.

Stendhal
5 years ago

I rode the prior version of the Pulsium for a year and was quite impressed. I don’t know whether the elastomer per se helped but Lapierre really nailed the power / comfort combination

Jeff Tillack
Jeff Tillack
5 years ago

I have the “current” model Pulsium and have to say it’s immensely comfortable to ride. I also ride a TCR (which I love to death) but the Pulsium is my go to bike for long distance, rough road adventures. I’m not sure how the elastomer works (and I agree with many comments above), but I can honestly say it does what it says “on the can”. Over the roughest roads it feels Cadillac smooth. I’ll definitely buy another one. Each to his/her own, but I like the look. It’s different from all the run of the mill, similar looking bikes in the peloton.

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