VN Bike Lab: Testing Endurance bikes

For the June issue of VeloNews, we’re testing four endurance bikes in the lab and out on the paved, dirt and cobblestone roads.

For the June issue of VeloNews, we’re testing four endurance bikes in the lab and out on the paved, dirt and cobblestone roads.

For the June issue of VeloNews, we quantified the performance of four endurance bikes while riding modified (read: bumpy) rollers.

As we did with aero bikes in the April issue, we are subjecting each bike to hours of ride time under different riders, then quantifying the bikes’ unique characteristics in the lab to see whether or not the numbers match our riding impressions.

Largely popularized by the Specialized Roubaix, endurance bikes are designed to take the edge off of rough or longer rides. Although each manufacturer has slightly different designs and associated claims, the category as a whole features taller head tubes, slightly longer wheelbases and some engineered comfort.

We’re testing four endurance bikes: the Cannondale Synapse, the Lapierre Sensium 300, the Bianchi Infinito and the Roubaix. Each of these bikes is spec’ed with Shimano Ultegra compact groups.

Over the next two weekends, we will be riding these bikes in the cobbled cyclosportifs of the Tour of Flanders and the new Paris-Roubaix Challenge. (This is strictly for business, mind you; any personal enjoyment will be purely incidental.)

Before we took the bikes to Belgium, we took them into the lab for two tests.

Our torsional stiffness test, first used with the aero bikes in the April issue, measures lateral stiffness under pedaling load. In addition to measuring how much each bottom bracket moves under 100 pounds of pedaling force, we also measured movement at the head tube and at the seatpost.

To explore the claims of the endurance bikes, we created a new test designed to replicate the conditions of choppy roads. To do so, we welded beads across the full width of two sets of Kreitler rollers. One on set, we welded a 1/8-inch bead across the front roller and one of the rear rollers. We did the same thing with a ¼-inch bead on the second set. The 1/8-inch set felt like riding really rough chip-seal roads. The ¼-inch set was pretty jarring – more like riding tightly spaced cobbles like you’d find in a quaint downtown area.

To quantify how each bike performed, we placed sensors at each dropout, on the top of the stem and on the top of the seatpost. We recorded 30-second samples while riding the bikes in the same hands-on-hoods position at 30kph in the same gear with tires all at 90psi.

Microbac Laboratories, a specialist in commercial, industrial and legal testing, assisted us in the creation and execution of the tests. Basically, we told them what we wanted to measure and why, and they applied the science. Over the course of this second test alone, testing 88 configurations, Microbac recorded and processed 2.8 million data points.

In addition to testing each bike as it came, we also tested each of the bikes with a control set of wheels with 25mm tires. Also, we explored the effect rider weight had on the bike, with a 145-pound guy and a 190-pound guy both riding a 56cm bike. (Conveniently, tech writer Caley Fretz and I have the same saddle height and stem-length preference, eliminating a number of variables.)

To see how each bike fared, pick up the June issue when it hits newsstands on May 1. In the meantime, you can read the April aero bike test online via Coverleaf.