To ride a road bike quickly and enjoyably, you need motivation, stamina and strength. But the racing bike must also run well, and for many cyclists the fascination also lies in the technology. The components fitted determine the riding impression of a bike even more than the frame. In our tests, the equipment therefore plays a relevant role in the final score. In order to be able to assess the components used, we also carry out ongoing tests of these individual parts.
In addition to wheels and tyres, this naturally also includes the components that make up the drivetrain, gears and brakes. As a rule, they come from one manufacturer and are assigned to individual groups within them. These follow a certain hierarchy and differ in terms of quality, function, weight and price. Functionally, the differences are comparatively minor, apart from the fundamental difference between electronic and mechanical circuits. All the manufacturers' products work well and the differences lie mainly in the weight and workmanship of the parts.
We determine and evaluate these properties for drive groups:
Weights
All individual components are weighed by us on the laboratory scales
Processing
Evaluates the manufacturing quality and appearance of the parts and surfaces
Assembly/adjustment
Evaluates how assembly, disassembly and adjustment work can be carried out. Special tools, screws that are difficult to reach and unnecessarily time-consuming work lead to deductions.
Drive
Hardness of sprockets and chainrings: The gears are tested using a hardness testing machine. The determined hardnesses (according to Vickers) are an indication of the wear resistance of the alloys and surfaces used.
Chain: The sections of the test chains are riveted together to form test chains, mounted on a test machine and tensioned. At a ratio of 53/17, the chains are run in with original lubrication and then degreased. This is followed by 75 hours with 300 newtons of chain force and a further 15 hours with 500 newtons. After every 15 hours, quartz sand, water and simple oil are applied to the chain. The chain is washed and measured at 100 newtons of chain tension.
Inner bearing tightness: Evaluates how well the bearings of the crank unit are sealed. In addition to the type of seal, empirical values from previous tests and practical experience are also taken into account.
Crank stiffness: Measures the compliance of the cranks in simulated pedalling on the test stand.
Circuit
Switching behaviour: Primarily based on practical tests. It is graded on how quickly and quietly the sprockets or chainrings can be changed with and without a load.
Trains: The shift cables are tested for wear resistance. Water and quartz sand are added at defined intervals and the friction of the cables is measured several times.
Range: The durability of the battery of electronic shifting systems in a laboratory test: A self-built robot operates the shift buttons, a counter documents the movements of the rear derailleur and front derailleur.
Brakes
Laboratory test on the TOUR brake test benchThe front brake is tested with the associated lever, disc and pad. The braking forces are measured in dry and wet conditions, and it is also determined whether the brakes have a tendency to fade when heated. The dosage capability, which depends on the entire transmission path, is also recorded. Practical tests are also carried out, for example to analyse the stability of the brakes.
Jens Klötzer
Editor
