After the wiring was finished, there was nothing more I could do with the bike still on the table I built for it.
Down on the ground at last! It sat on the table for nearly two years, and once it was on the ground, holy cow! It was suddenly so damn low looking. So cool.
I charged it for just a few minutes (first time ever, even while the batteries sat for nearly two years, which is not good) and then I went on a quick test ride. Everything seemed to work just fine, only there was a little noise coming from the front wheel because, in my haste, I hadn't attached the front brake linkage and this caused a lot of noise to come from the front hub. I secured the front brake to the fork but that was all I had time for that night.
The test drive was extremely short but very promising. It was completely silent except for a little tire noise, some wind noise, and the clanking coming from the front hub. I only got up to about 30mph, but to my surprise I didn't experience any strange effects from having worn out shocks and an extremely heavy rear wheel that is also badly out of balance.
The next morning I took it to the big car & motorcycle show I was working so hard to get it ready for. Thankfully the show was only three blocks from my house because the bike didn't have any foot pegs yet!
When I was leaving the show, I got on the road and once I was clear of the spectators, I goosed the throttle pretty good. Wow it was fast! Much faster than my 200cc Honda CL200, and I wasn't even all the way on the throttle. But immidiatly after that the power started to cut out and the motor shut off, the analog voltmeter was reading zero, and I coasted to a stop. I had to push the bike the two remaining blocks home.
The next day I plugged in the charger and after a few minutes I turned on the bike and it was acting like everything was normal again. But I couldn't charge it for long as I had meet my folks for lunch, and I don't yet want to charge it unattended.
What I believe happened is that the batteries where too low and when I gave it full throttle, it caused a large voltage sag that was enough to trip the battery management system and it shut down the battery. I could have proven this if I had thought to check the battery pack voltage, and if it was reading zero than this theory should be correct.
I need to charge it for a many hours and then give it another test drive. But I want to get some foot pegs before I do any more testing. Gotta walk before you can run, I guess.
When the bike was at the show, the analog gauge was saying the battery was at 50%. The gauge is not a typical voltmeter, it is volt charge meter and the manufacturer (Kelly) says it "indicates from ~80% peak voltage to peak voltage of the battery, corresponding to 0%-100%." I bought the 72v meter because I believed that was what I needed, but now I think I should have bought the 84v meter because that is the peak voltage of my pack, 72v is only the nominal voltage. 80% of 72 is 57, so when the battery is at 57 volts, it will say it is 0%. And when the pack is at 72v, it will say it's at 100%, but the below chart says that is actually 50% charge.
Instead of fixing that problem and others, I worked on producing a new youtube video for this build. Probably the final one. Here it is:
Here's what I need to work on now:
- Turn signals. It looks like a show bike but this bike is actually for riding so it will need turn signals to be safe in traffic.
- Foot pegs. Right now I just have temporary ones but they're too dangerous.
- The brake cable is too long because the handlebars are lower than OEM. Need to remedy that.
