how hot is too hot?!

[neilhapgood]

hi all,

apologies second post from me in one day!

so I have the tongsheng TSDZ2, 48v 500w with a 48v 17.5ah battery.

I am using it to pull a kids bike trailer fairly full of watersports equipment, it probably weighs about 25kg in cluding the trailer, I need it on the highest level of assist at all times.

If I really push it and do about 20mph on the flat the motor is getting hot, I can touch the outside of the casing but it is bordering on too hot to touch, must be about 40 degrees.

I appreciate there is a point at which these motors overheat but wondering what that point is?

My usual ride takes about 30mins.

Any advice as to whether I am heading for a disaster or if this level of heat is OK would be fantastic.

Many thanks

Neil

 

[MontyPAS]

hi all,

apologies second post from me in one day!

so I have the tongsheng TSDZ2, 48v 500w with a 48v 17.5ah battery.

I am using it to pull a kids bike trailer fairly full of watersports equipment, it probably weighs about 25kg in cluding the trailer, I need it on the highest level of assist at all times.

If I really push it and do about 20mph on the flat the motor is getting hot, I can touch the outside of the casing but it is bordering on too hot to touch, must be about 40 degrees.

I appreciate there is a point at which these motors overheat but wondering what that point is?

My usual ride takes about 30mins.

Any advice as to whether I am heading for a disaster or if this level of heat is OK would be fantastic.

Many thanks

Neil

Probably not the best motor for the heavy work you are describing!
Personally I would slow down a bit and save your motor..........

 

[vfr400]

hi all,

apologies second post from me in one day!

so I have the tongsheng TSDZ2, 48v 500w with a 48v 17.5ah battery.

I am using it to pull a kids bike trailer fairly full of watersports equipment, it probably weighs about 25kg in cluding the trailer, I need it on the highest level of assist at all times.

If I really push it and do about 20mph on the flat the motor is getting hot, I can touch the outside of the casing but it is bordering on too hot to touch, must be about 40 degrees.

I appreciate there is a point at which these motors overheat but wondering what that point is?

My usual ride takes about 30mins.

Any advice as to whether I am heading for a disaster or if this level of heat is OK would be fantastic.

Many thanks

Neil

Warm is OK. Hot isn't. As I said in the other thread, it's not speed that makes the motor hot, but inefficiency. Inefficiency comes when you pedal too slowly. With your new gearing, your motor shouldn't get hot at a steady 20 mph. It more likely got hot when you were going slower.. If the bike slows down, you should change down a gear to get the cadence back up to 70 - 75.

 

[peter.c]

After running the tsdz2 for the last year on various bikes the following points
Keep the legs spinning on the pedals even in turbo mode the human effort is a must -yes they get hot if you cannot touch the outer case it is far to hot, the controller is air gapped the outer is just a cover not a heat sink use of the throttle only for long periods will cook it
The standard chain wheel and 11 0n the rear is best,
Do not waste money on the larger chain ring as the alignment is useless [flat not dished like standard] and top gear is out of the power band if the motor labours the blue gear will strip
The tsdz2 is well down on power compared to the equivalent rated bbs02 by about 40-50% at peak power
the 750watt is 15 amps [18amps on the 2020 model] the bbs02 is 25 amps+
For cyclists who want some assist the tsdz is ok but not for hard work

 

[neilhapgood]

Again many many thanks to all. Peter is there any indication you can give of when hot becomes too hot! If I can hold my hand on the CASING without risk of burning myself is that OK?

About to go now to try higher cadence!

Thanks again!

 

[peter.c]

The super long tsdz2 open source thread on endless sphere, contains many suggestions and modifications included is a temp sensor
Rule of thumb it shows a power loss but by then it can be to late
use one gear bigger than you think you need and pedal harder , its more heat if you pedal to slow for the same speed.
Cadence is king on the tsdz no ghost pedalling like on a bafang
Notice it more now as have a bafang in one bike, for lazy rides

 

[neilhapgood]

amazing, thanks all. Just got back from a ride and went for higher cadence and it made a real difference, thanks so much for the advice, the motor was warm to touch but not hot.

Im terms of damage through overheating is the damage done as soon as it hits too high a temperature or does it need to run for a period of time at the high temperature to cause damage?

 

[peter.c]

Prolonged abuse at high temperature is made far worse if it is a hot day, and hill climbing in the wrong gear if you need turbo mode all the time it is probably in the wrong gear
Be careful in the largest cog on hill starts [if a 42] and in turbo mode wheelies /180 back flips if you stomp on the pedals
Rule of thumb choose the right motor power for your style of riding -comfort- needs and ride in the right gear to suit the motor cadence and do not pull away in to smaller gear and all should be ok
The tsdz2 is not designed for low effort riders , the motor assist still requires human effort to attain a good top speed

 

[Nosweat]

How can it even get warm if you are cycling at 20mph? I thought they cut out at 15.5mph?

 

[neilhapgood]

no you can adjust the top speed to 45kph.