Four endurance bikes put to the test on the cobbles and in the lab

The current issue of VeloNews features an in-depth comparative review of four endurance bikes that distills the results of two lab tests plus the feedback from four testers who rode the bikes for a few weeks in Belgium and France, including in the Tour of Flanders and Paris-Roubaix cyclosportifs.

After testing aero bikes for the first VN Bike Lab review in the April issue, we tested what we are calling endurance bikes — machines with slightly taller head tubes and slightly longer wheelbases than pure race bikes. All four were built with Shimano Ultegra — three with compact cranks and the fourth with a triple — and they sell for $3,000 to $3,700. Also, all four come with bold claims from the manufacturers about various comfort-enhancing features like vibration-damping elastomers.

The four bikes were Cannondale’s Synapse Carbon 3, Lapierre’s Sensium 300 CP, Specialized’s Roubaix Expert and Bianchi’s Infinito.

Before taking the bikes to Europe, we did two sets of lab tests. First, we did our torsional stiffness test, which simulates pedaling load and measures the bike’s stiffness at the bottom bracket, head tube and seatpost. We do this test for all VN Bike Lab reviews. The second test was created specifically for the endurance bikes to measure how much vibration was transmitted up through the bike from bumps on the road.

For this second test, we attached accelerometers to the bicycle at the front and rear dropouts, the top of the steerer tube and the seatpost just under the saddle. We then rode the bikes on two sets of modified rollers that had 1/8-inch and 1/4-inch metal seems welded crosswise.

With the accelerometers, we measured acceleration in g’s. (G is acceleration measured in units of gravity. For example, 2 g = 2 times the acceleration of gravity.) The lower the g number, the better the bicycle was isolating the rider from the vibration of the rollers.

We normalized accelerometer position, bicycle position, rider, rider position, tire pressure, speed and gear used. We intentionally kept the stem and handlebar out of our test. These are often swapped out by the rider, and size and material make a big impact (see our May issue Tech Report). Instead, we focused on how the frame, fork, wheels and seatpost performed as a system.

It’s important to note that we made our ride impression notes without knowing the results of the lab tests. The riders were not privy to the lab data until the ride testing was complete.

So then we packed up the four bikes and headed to Belgium to cover the spring classics. Before we felt the rough old roads of Europe, we felt the fresh sting of flying with bikes — $150 per bike, each way. Thank you, United. Geez.

Although the airline gods were cruel, the weather gods smiled on us. Belgium experienced a heat wave in April, and we took advantage, riding every day from our base in Kortrijk. The cyclosportifs, held the Saturday before the WorldTour races, were a great time. More than 19,000 people registered for the Tour of Flanders cyclosportif this year. The Paris-Roubaix Challenge, a first-year event, was a smaller affair, but plenty brutal.

As with all VN Bike Lab reviews, we rated each bike on a 100-point scale in eight categories: two scientific tests (for a total of 30 possible points), three types of ride quality (30 points), value (20 points), user friendliness (15 points) and weight (5 points).

We were pleasantly surprised to discover that our rider impressions matched the lab tests. Bikes that performed well on the cobbles did well in the big-bump test, while bikes that handled chip-seal roads comfortably did well on the small-bump test. We printed the results of both vibration tests, and scored the bikes based on the average of the two.

Featuring the VN Bike Lab endurance bike test, the June issue is available in bike shops and on newsstands now, and can also be read online via Coverleaf, where you can purchase a single issue or a subscription. Print subscribers interested in receiving a digital subscription can get one for $10 by calling our customer service center at 800-494-1413. (Print subscribers can convert to receive only the digital version at no charge.)

Next up for the VN Bike Lab — women’s bikes. For that test, we enlisted a diverse group female testers, from commuters to recreational riders to elite athletes. That review, plus a women’s clothing section, will run in the July issue, which goes on sale next month.