Should I worry about overheating the hubmotor uphill?
Posted by catboy519@reddit | ebikes | View on Reddit | 11 comments
Important context: my ebike has a 250watt rated front wheel motor. Bought in a flat area so maybe the bike isnt built for hills. Climbing a very steep hill will push the bike to its max torque at near stalling crawling speed slowly. I'm guessing the motor would be warming up with hundreds watts.
I don't know if the controller detects motoroverheating. I know though that the motor has 3 big thick and 6 smaller wires so quite possibly it communicates about stuff quite well. But maybe 3 phase needs 6 wires so I dunno there.
I won't be riding uphill if it forces me below 5mph continuously. At that point I will step off and walk. But what about speeds like 8mph? (motors topspeed is ~21mph)
Under the "safety assumption" that maybe the ebike does not have proper thermal throttling for the motor, what should I ride like if I need to climb long uphills? Do I maybe alternat between walking and riding then every minute?
Big_footed_hobbit@reddit
I just beat mine uphill for 45 min straight. It is very hilly and the monitor shows 600w peak never throttled.
My gf bike was the cheap one at the market. It even hauls my butt with groceries uphill.
I’d not worry but here top speed is limited to 25 km/h.
catboy519@reddit (OP)
Max power alone doesn't overheat motors.
Power combined with low RPM does.
Ohm_Slaw_@reddit
Yes.
What you want to avoid is "lugging." Where the motor is turning very slowly and the throttle is maxed out. Right under the stall point. This is the point of maximum heat generation.
If you can keep your speed up, say 10 MPH, going up the hill you're fine.
Most motors do not have a temp sensor and don't do thermal throttling. It does exists but it isn't common.
You can check the temp yourself. Put your hand on the motor. If you can hold there comfortably, it's ok. If you have to remove your hand, it's too hot. It's a crude check, but it's pretty good.
catboy519@reddit (OP)
How do ebikes determine when to switch from peakpower to nominalpower, if they dont know how warm the motor is?
Ohm_Slaw_@reddit
If you have a temperature monitor in the motor and the controller is programmed for it, the controller will throttle back the motor when it overheats. This feature is not common.
Rude-Possibility4682@reddit
Are you using the pedals, or just relying on the motor by itself.
unseenmover@reddit
using throttle only yeah i think that would cause it to over heat.
catboy519@reddit (OP)
My ebike has a motor in the wheel.
unseenmover@reddit
mine was a hub motor..as well
catboy519@reddit (OP)
Was?
unseenmover@reddit
went the mid drive route.