I rode my z20b to work yesterday for the first time ever (a 10 mile trip) and it worked great! It only consumed about 1/4 or less of my battery charge.
But on the way home, I ran into a problem. In retrospect, I think this has been a problem with the bike for a while (before I got the new controller). The problem, I believe, is that the rear brake is clamping down and not releasing. This happens even when I don't have my hand on the brake.
What happened was: I left work and the bike was riding fine. About half way home, the bike started to slow down. Then it would only go about about 5 - 10 mph. Then not at all. I pulled off to the side of the road. With the ignition on, I found I could not push the bike (as I normally can do). I turned it off and on. The bike would go very slowly for a few feet, then stop. Again, I could not push the bike any distance at all - as if someone were squeezing the brake. I waited, thinking the bike needed to cool down (it was 102 F yesterday). I waited in the shade. But the next test, same result. Finally I threw off the circuit breaker and waited a bit longer. Turned everything on. Even though I could not push the bike very easily, it seemed to be better. I started riding down the road slowly. Eventually, things started working again and I was able to travel full speed. But by the time I got home, almost all my charge was gone. The gauge was blinking red when I pulled into the garage.
I started thinking over the ride home. I remembered that before the bike stopped, the bike had started to act strange. When I was approaching a stop and I took my hand off the throttle, rather than rolling to a stop (like I was used to), the bike was stopping fast, like I had the brake on. And I've seen the brakes lock up before, but I thought it was something wrong that I had done. For example, some time ago, I was backing up out of the garage (sitting on the bike and pushing back with my legs) and noticed it was very hard to move the bike. But I had the ignition off. So I thought it had some connection with that. Again, I turned everything off and turned it all on, and the problem corrected itself.
Can anyone tell me how the brakes work? Can the controller or anything else activate them? What do I need to diagnose and fix the problem? Can someone send me some pictures of how to dismount and inspect the brake pads to make sure everything is working like it should? Can you think of anything else this could be?