For joint testing with a Comp 17 mid-drive system with a power of 250 / 350W and a 36V battery with a capacity of 11.6 Ah, the second prototype of the universal frame of our development was made; all the shortcomings of the first one were taken into account in the construction. In the new version of the frame, the distance between the axles of the wheels was also reduced, and the prototype geometry was optimized for size L. The Comp 17 drive motor was installed in the U-shaped fixture patented for our frame using serial bolts.
Along with this, a semi-integrated headset system was used to mount the Suntour XCR RL-R suspension fork with a 100-mm shock absorber stroke in the steering tube. The CAD simulation that was carried out earlier in Solidworks showed that the frame has an adequate margin of safety and must withstand a cyclist weighing up to 120 kg. For comfortable use, the frame was fitted with Shimano M365 hydraulic disc brakes with 180 mm discs, as well as a cassette with 10 sprocket, rear derailleur and Shimano Deore series shifter. On the received e-Bike, Maxxis Ikon tires were installed with a wide tread and the diameter of 27.5 inches.
Thus, we designed a dual-use prototype of an electric bicycle – fast and manoeuvrable, for movement in the conditions of urban traffic, and also a sport MTB – for country trips on rural roads. As the first test drive has already shown, the used tires, suspension and transmission provide excellent grip and comfort both on the roads and on asphalt, and the frame has sufficient elasticity.