Some versions of the software will even allow you to set the maximum speed right up to 700rpm, these are all the maximum values for each or the parameters that my MP4 controller would actually accept:
But an unloaded wheel speed of 450rpm
(34.75mph or 56km/h with a 26" wheel) is about the most the motor will achieve using a fully charged 16 cell 48V LiFePO
4 battery:
The 360rpm default setting will still allow a maximum speed of up to 28mph under load with a 26" wheel.
Setting the speed higher than 360rpm
will not harm the motor or the controller in any way, as the voltage of the battery will automatically govern the maximum rpm.
If you were to set the maximum speed to 700rpm, it is unlikely that the bike would be any faster on the level, although it should be marginally faster down a steep hill, but you would probably notice that the throttle was very sensitive and only needed to be moved just over half way to achieve maximum wheel speed
(~360rpm). The remaining movement of the throttle from just over half throttle to full throttle would make no difference to the motor speed.
To reach 700rpm, the motor would require at least 94V, but this much voltage would definitely damage the standard internal controller.
With a fully charged 96V pack
(and a suitable external controller) the MP4 motor should theoretically be capable of reaching ~860rpm, but I think it would need some accurate balancing along with some substantial torque arms to prevent it from shaking loose.
According to my calculations, the 114V provided by a fully charged 96V pack should produce an unloaded wheel speed of ~66mph
(107km/h).
So, if you are not concerned about the safety of yourself
or other road users, animals and pedestrians and are really determined to go as fast as possible down very steep hills, then you can set your controller's maximum speed to 450rpm.
Setting it any higher than 450rpm
will not increase your maximum downhill speed, unless you are using a fully charged 15s LiPo pack, in which case you may want to increase it to 475rpm in order to try and achieve the extra 2mph.
Alan 
