I am hoping somebody can please give me some advice on a hub motor to use for my e-mtb application.
I’m working on a roller drive system with a single 63mm motor mounted under the cranks. The Turnigy 6354 140KV motor I’m using currently works well at speed, but quickly reaches the high-temp cut off when climbing hills. I tried integrating a heat sink to the mount but it didn’t do much at all.
This setup is only intended to be an assist to pedalling, and as such I have limited the power to 300w.
I know heat management is a problem for slow moving hub motors, but I expected a better result due to the low 300w power level. Though the system works well at speed, when crawling up long hills at ~10km/h the amps get up and we hit the 80°C cut-off within a few minutes. .
I want to be able to climb looong hills on a hot day at 10km/h (ideally less) with 300w of assist. Even dropping the KV down to ~90 I still need to pull between 30-45A for maybe half an hour or more. From what I’ve read here it seems that twin Hummie/Enertion/Meepo setups can climb hills pretty darn well. I’m hoping someone can recommend a motor that will work for me in this application - especially considering the moderate sustained current. I know some motors have less resistance/KM than others, so its not just a question of changing KV and amps to avoid heat saturation.
- I Already plan to upgrade to 10s battery, which will allow me to run a 80~100kv motor and still keep top speed around 40km/h.
- I only have 80mm of width to play with so his may rule out some super long motors.
- At the moment the VESC temp barely gets above ambient. Hopefully a motor that can pull higher continuous amps doesn’t shift the problem there.
- Ideally I’d like to buy a single motor, and need to be able to remove any urethane outer to add my tyre roller.
- Flipsky VESC 4.12 in aluminium heat sink case. Set to 300w/45A max.
- Turnigy SK8 6354 140kv motor
- Zippy 7s lipo battery
Thanks in advance for any help. As I’ve worked through this project I’m always amazed to see so much expertise in the one place.