fechter said:
The 24 FET Powervelocity controller looks like it might barely fit if the flanges are cut off the case. I'm tempted...
For sure the motor will need cooling if you push it too hard. Since it's an inrunner, just having a fan blowing on the outside will help a lot. For serious overpowering, it may be possible to make it water cooled.
We need to find out just how much power the sur-ron can handle before it needs cooling. If it is true that with 6KW it doens't overheat, then it can probably handle easily 10KW without overheating.
I push only 8KW on my bike now and that is plenty enough power for me, and if the Sur-Ron at 6KW pulls at low speed like a 14KW hub motor bike like Alex mentioned, 8-10KW will be plenty enough for me where I would not even bother with higher power that may need cooling.
55MPH is also the top speed of my hub motored bike and at that speed with such a light weight bike I wouldn't really want to go much faster than that.
SO for the majority of us I think 8KW-10KW would be ideal. Really 10KW if you are 200lbs+ and 8KW if you weigh much less.
There is a chance that since i'm only pushing 8KW on my hub motored bike, that the Sur-Ron at 6KW with the newer controller would be close to the power of my bike , which I find the 8KW ideal. The thing is I really push the field weakening on my Max-E which gives me that high 55MPH top speed with my smaller 17" rear wheel. I doubt the Sur-Ron sine wave controller maximizes the full 6KW with the field weakening.