Even if you found a way I am not sure it would do much. I've messed around with the settings to no avail. The controller is only 12A so the bike will peak at ~500 watts at full charge. Most speed pedelecs run 48v batteries and 20+ amp controllers. If you want speed at an affordable price go the kit route.
I am about to find out. Voltbike gave me cryptic manual in bad English. However, there is a top speed setting. Max is 50km. Mine was set at 32km. Just changed. Report back in a few hours. If works will tell you how. The manual covers 14 settings. However there is actually 16 on the controller. Dunno what the other two do. The controller is close to this one. Manufacturer must be JS.
So... Tested on the absolute flatness of Richmond just now. Throttle open, no pedaling, power adjusts itself to maintain 32km/hr on the nose. Didn't expect speed bypass to be that easy. It's hard wired.
There was a small improvement. Previous to adjustment, at 32km, it almost felt like the bike was slowing itself down. Trying to pedal above 32 was tedious. The speedometer seemed stuck at 32.
With adjustment power is supplied in decreasing amount up to 36km/hr when power zeros. That is a small gain that I will take. And you're pedaling pretty fast at 36.
Will post how when get home.
One thing... The motor seems to have no power on hills. Quite wimpy. I guess that's where 48V comes in.
I love the bike frame. I suppose the drive train could be upgraded to 48V by sourcing