Our Development & Testing Programs
Bench-testing
On this website and in our promotional literature we make reference to our use of bench- type testing to supplement field-testing. Although research and development engineers use such testing extensively, its value or even its significance may not be so obvious to everyone. The advantage of bench-scale simulated-service testing (relative to field testing) is that it allows control of extraneous variables, so we can make valid comparisons. In short, bench testing points the way to product improvement, often to an extent not possible with field testing.
Most of the electrical components on our e-bikes (motors, controllers, throttles, batteries) have been selected from candidates screened and evaluated by such tests. We have developed specialized test equipment to achieve many ends. A variable-load simulator (visit our shop to try it) allows us to simulate a wide range of uphill grades and measure the response of the power-assist system. In optimizing parameters for our bio-responsive control system for example, we repeatedly increased the simulated grade, and measured the e-bike’s response as the control system reacted to make it negotiate the grade without exceeding the set limits.
Other test equipment allows us to evaluate and compare battery discharge characteristics & capacity under load. A hub-motor dynamometer (Figure 1), measures motor output torque as a function of speed and electrical power input. With this we establish motor, controller & battery performance characteristics (Figure 2), and have determined optimal voltage levels and current limits.
Field-testing
Bench-scale testing can point the way to product improvement, but it is ongoing field-testing that refines the product and ensures it is as functionally perfect and as robust as we can make it. We rely heavily on beta testing and post-service inspections. Most importantly, we ride these bikes a lot ourselves, and are continually monitoring for improvements. From time-to time we even involve our customers in our R&D. At present we are running controlled experiments with the cooperation of two customers who have exceptionally demanding riding conditions and who are essentially “torture-testing” our bikes. One of these is being run regularly under high load with the current cutoff set at a higher than normal amperage, and is instrumented with temperature recording devices; the other sees frequent heavy braking and is being used as a test bed for different brake pad materials.
Figure 1: Dynamometer for testing hub-motors under load
Figure 2: Example of dynamometer-generated data
