I've been doing a little bit of riding on the scooter to test how everything is working and so far it's been pretty good. In terms of range I've been consistently getting 30km per charge but I haven't really pushed it yet as there are still some issues with the battery management system. Once that's sorted out I'll be able to charge the battery pack to a higher voltage and run them lower without risk of damage.
I've also made some changes to the gearing as my top speed was around 65km/h. The shop where I bought the motor said that I could safely run it at 1 mph per volt which at 51.2V equates to 82km/h, so I changed the small sprocket inside the crank case from 12 teeth to 14 teeth.
The taller gearing means that it doesn't accelerate as well as it did before but it now goes above 75km/h without any problems.
However, at these higher speeds, the scooter develops a noticeable wobble like the tyres are stuck in grooves in the road or something and the scooter moves a little from side to side. I'm not sure if it's coming from the front or the back wheel but it's pretty scary when it happens! It was pretty windy at the time which might have played a part but after doing a bit of searching online it seems like small wheels, tyre pressure, anything loose, bearings, frame or forks out of alignment, something to do with suspension? might be responsible. Is anyone an expert in these things that can shed some light and is there a way to improve or fix the problem?
As a start I'll check the bearings are ok and everything is done up like it should be. I was also thinking of getting some new inner tubes and tyres as I'm not sure how old these ones are.