I have a 2 year old Ancheer eBike that tops out at 15mph (on a good day). The one I owned before, which was exactly the same model, would do 19-20. I once saw something on the web that showed how you could run a jumper to a couple of wires on the controller connector to get more top speed, but now I can't find the article anymore. Does anyone know how to do this? 15 is a little slow, and I know the motor is plenty powerful for 20 mph, but is being limited to 15 for some reason.