Z20 PLUS
Pluses: Very robust construction Powerful and fast Suitable even for taller riders (I’m 185 cm tall, but my 203 cm neighbor was able to pedal it too) My version allows throttle use in any selected PAS mode (I believe earlier versions only allowed throttle in PAS 0) When throttle is active, pedaling doesn’t interrupt it — useful for unloading the motor and extending range When folded, I was able to fit it into the trunk of a VW Golf! Neutral / Minor downsides: The weight — expected with this type of bike, but it still requires some strength to lift into a car trunk Folding mechanism could use occasional oiling The chain seemed to have slightly more oil than necessary Directional side lights are very hard to see during daytime, and the thumb switch is not easy to identify or feel for its current position My observations: Pedaling with a cadence sensor in urban areas can be tricky. Any pedaling leads to reaching the preset speed of the selected PAS level — it's hard to maintain a speed "between" PAS steps. The only precise way to control speed is using the throttle, which may go against local legislation in some countries. Suggestions for manufacturer improvement: The brake light is very weak and also much smaller than the tail light — switching their positions might be a good idea Range Test Review I tested the mileage range of my e-bike under the following conditions: • The battery was fully charged for the third time. • Test temperature ranged from around 20°C at the start to 17°C at the end. • My weight is 76 kg. • The terrain was very flat, with a maximum elevation change of about 15 meters. • The surface was asphalt, wind was light, and tire pressure was set to the maximum. • I used only pure electric mode (no pedaling), riding mostly on PAS level 4 at full throttle. • To minimize environmental effects (wind, slope, etc.), I rode a "there-and-back" route — returning the same way I came. • I maintained a steady speed with very little acceleration. At the beginning, the bike maintained a speed of about 36–38 km/h, and toward the end, it dropped to around 30 km/h. I ended the test when the battery voltage dropped to about 42V, mostly because it was getting dark and cold to me. The total distance I covered was 45 km. Since there were still about 2V left in the battery, I estimate that a full discharge would give close to 50 km of range in full throttle steady mode — which is pretty good! Note: This was all done at PAS level 4, with an average speed slightly over 30 km/h. For reference, 40V is the cut-off voltage where the last bar on the battery indicator disappears. ________________________________________ Battery Behavior & Power Usage The default battery that came with the bike has a dynamic ‘voltage’, which changes depending on the current draw (in Amps): • At PAS 4 with a steady ride, my display showed around 10 Amps, and voltage was about 52V when fully charged. That means power consumption was roughly 500W (52V × 9–10A). • Toward the end, power dropped to about 300–380W (42V × 7–9A). • After resting a few minutes, the voltage would rise to around 44V — but this can be misleading and shouldn’t be seen as “available” battery. In city rides, when the battery is near 42V, heavy acceleration can spike the current to 20 Amps, which may cause the voltage to drop below 40V. When this happens, the bike cuts power to the motor and you’ll need to pedal manually. However, once voltage rises again above 40V (after stopping or waiting), the motor kicks back in. You can also reset the system by switching it off and on again after some rest time.