Lapierre has been on the roads of Europe since 1946 and states side since 2005. Mainly known to the racing crowd in the United States due to their sponsorship of the Francaise des Jeux team, Lapierre builds a wide range of bikes to meet the needs of cyclist at all levels. While the performance sector, usually noted by a taller head tube, longer chain stay and a more upright riding position, as exploded in the last couple of years, Lapierre was ahead of the game with their Sensium line that evolved from the S-lite series in 2007. Updated and refined for 2012 the Sensium line employs a new shock absorbing elastomer connector integrated into the wishbone chain stays. The addition of this feature puts the Sensium 400 into the leagues of industry leaders like the Specialized Roubaix SL2 and Trek Domain.
The Sensium 400 frame is heavily sculpted monocoque carbon with each tube being designed to increase lateral stiffness while increasing vertical compliance. The sculpted top tube arches dramatically downward from the head tube and houses the rear brake cable internally. The head tube is tapered from 1.5-inch at the lower headset bearing to 1.125-inch at the top bearing. The down tube is bi-axial ovalized with a sharp angular profile to stiffen both the front triangle and bottom bracket. The front and rear derailleur cables are run internally through the down tube. The only tube in the front triangle that is not oversized is the seat tube housing a small diameter 27.2mm seat post. This combined with a short seat tube length allows for the seat post to flex slightly for added comfort. All of Lapierres efforts to stiffen the front are then mated to a rear triangle designed to smooth the tarmac.
To provide a more compliant ride the chain stays feature a slightly vertically ovalized profile near the bottom bracket before tapering to a more conventional round shape at the rear dropouts. The alloy dropouts bolt to the chain and seat stays and are replaceable in case of a crash. The seat stays are at the heart of the Sensiums ride quality. The thin and narrow seat stays arch forward slightly to provide a bit of vertical compliance. Just above the rear wheel the seat stays merge into a single strut that houses an elastomer connector. The strut is a single piece of carbon, but with a relieved section in which the elastomer is housed. This design maintains the torsional stiffness of the frame, but allows for more vertical compliance. The elastomer absorbs hi-frequency vibrations that resonate through the frames and aids in isolating the rider. For a balance feel Lapierre completes the Sensium 400 with their own tapered carbon fork with curved blades.
Smooth and Snappy
Putting power to the pedals the Sensium 400 delivers as promised. The ride is noticeably smooth, but it was the bikes responsiveness and snappy feel that surprised us. Not as stiff as their Xelius race machines, yet mere mortals could produce little flex. The Sensium 400 tracks straight and power put to the pedals was efficiently delivered to the rear wheel. The Sensium 400 cruises down the road like a long wheelbase steel touring bike, infused with the geometry and quickness of a modern racer. The frame is light and stiff, yet lively with enough vertical compliance to make a noticeable and enjoyable difference.
The Sensium 400 is equipped with a complete SRAM Force group combined with a Ritchey Comp 4 Axis stem, Ritchey CompCurve handlebar, Ritchey Comp seat post and Ksyrium Elite wheels wrapped in Hutchinson Equinox 2 tires. A Selle Italia X1 saddle completes the setup. On the scale, the Lapierre Sensium 400 registered 16.6 pounds without pedals. The Sensium 400 is well equipped with a quality mixture of lightweight and durable parts.
The Lapierre Sensium 400 frame has a short seat tube and long top tube so make sure to test ride in order to lock in the ideal size. Our medium featured a short 52 cm seat tube length mated to a 54.7 top tube. The 72.5-degree head tube angle gives the Sensium 400 a stable and predicable feel, while the 73-degree seat tube puts the rider in a familiar position over the pedals. As with most machines in the performance bike category the Sensium 400 features a taller head tube and longer chain stays when compared to their race inspired counterparts. The head tube measures 160 mm while the chain stays extend out 412mm.
Turning skyward the Sensium 400 has little trouble keeping pace with machines that are classified as a race bike. The lively feel of the bottom bracket combined with the stiff and stable front end make the Sensium 400 feel quick when tackling ascents. The Sensium 400 ascended best in the saddle with the rider ticking over the pedals at a high cadence. This allows the rider to take advantage of the bikes vertical compliance and gives the impression the bike is floating up the climb with minimal effort. Out of the saddle efforts are greeted and rewarded by the snappy feel and the sensation of smooth acceleration. At no point did the rear of the bike feel soft or that the elastomer connector was adversely effecting power transfer.
Descending on the Sensium 400 is fast and inspires confidence. The slighter longer wheelbase and the frames vertical compliance allow the rider to ease up on the brakes and let the bike carve its way down the hill. On longer descents the elastomer damping system really became noticeable. A lot of the high frequency vibrations that fatigue the hands and cause the back to stiffen up are reduced, and while sharp impacts are felt, they are dramatically muted. It is only in sharp corners that the Sensium is at a disadvantage when compared to a race machine. With the longer wheelbase, taller head tube and less aggressive head tube geometry the Sensium 400 requires a corning technique with more counter steer and a greater exiting arch.
Once the road levels out the Sensium 400 settles into a comfortable rhythm smoothing out the miles under its wheels. It seems largely unbothered by road conditions or terrain it simply wants to keep rolling at a steady pace. Much of this sensation is a result of the frames well-balanced mixture of vertical compliance combined with a stiff bottom bracket and responsive power transfer.
The Lapierre Sensium 400 rider is looking for a machine with 90 percent of the performance of a race bike with the comfort of a long haul tourer. They want ride quality, but require performance that allows them to keep pace when the speed increases. The Sensium 400 delivers this with an extra bit of European flair mixed in that is sure to draw an admiring eye at the next Gran Fondos or club ride.
The Sensium line features four models. At the top is the Sensium 400, followed closely by the Sensium 300. The Sensium 300 utilizes the same frame but comes equipped with a mixture of Shimano Ultegra and 105 components. Lapierre outfits the Sensium 300 with a Ritchey Logic cockpit, Selle Italia X1 saddle and Mavic Aksion wheels. Next in line is the Sensium 100, which like the 300 shares the same monocoque carbon frame as the top of the line Sensium 400. The Sensium 100 is equipped with a mix of Shimano 105 and Tiagra components. Lapierre outfits the Sensium 100 with a Ritchey Logic cockpit, Selle Italia X1 saddle and Shimano WHR501 wheels. Finally the Sensium line is rounded out with the Sensium L, which is similarly equipped as the 100 but with womens specific handlebar, stem and saddle.