Wisper 705 Fried Controller

[DiggyGun]

I was servicing the bikes and giving them a good clean after a two week cycling holiday, when I found this on Mrs DGs bike.

She has a Wisper 705, (which is a rear hub drive with a 375 Wh battery) and it looks like the controller got overheated at some point and melted the wiring. I’ve disconnected and separated the connections. Now I’ll check on the Wisper website to see what controller is fitted. Some of the bike wiring will have to be cut back and some new pieces added to get them back to the right length. It looks like the thicker Green, Yellow and Blue wire caused the problem as the blue bullet connectors were the most melted.

It‘s booked in with Rutland Cycles for them to look at and repair what’s necessary.

This leads me onto the following questions:
- I see that the Yellow / Green / Blue wires go to the motor. So am assuming that this caused the problem.
- At one stage, we did go up three very steep (1 in 8) hills, (see graph). We were the lowest gear and the highest PAS setting. Could this have caused the motor to overheat to cause the problem. If that is the case, we need to re-consider riding the Wisper on steep hills. Either not go up hills or change the bike.

 

[Nealh]

Yes in highest PAS level one has to keep the riding and motor speed quite high other the heat builds up. If you had tried to hold the controller you would have ended up with secondary degree burns.
It is most likely only a 6 mosfet controller, a 9 or 12 mosfet model will handle the heat better. But it is the climbing speed, high current and steepness of inclines that causes the heat issues.

 

[Wisper Bikes]

I was servicing the bikes and giving them a good clean after a two week cycling holiday, when I found this on Mrs DGs bike.

She has a Wisper 705, (which is a rear hub drive with a 375 Wh battery) and it looks like the controller got overheated at some point and melted the wiring. I’ve disconnected and separated the connections. Now I’ll check on the Wisper website to see what controller is fitted. Some of the bike wiring will have to be cut back and some new pieces added to get them back to the right length. It looks like the thicker Green, Yellow and Blue wire caused the problem as the blue bullet connectors were the most melted.

It‘s booked in with Rutland Cycles for them to look at and repair what’s necessary.

This leads me onto the following questions:
- I see that the Yellow / Green / Blue wires go to the motor. So am assuming that this caused the problem.
- At one stage, we did go up three very steep (1 in 8) hills, (see graph). We were the lowest gear and the highest PAS setting. Could this have caused the motor to overheat to cause the problem. If that is the case, we need to re-consider riding the Wisper on steep hills. Either not go up hills or change the bike.

View attachment 46970View attachment 46971View attachment 46972

Hi DG please call our office and talk to Adrian in dealer support. He will look after you and send the correct connections FOC if you are happy to do it yourself? This is a known issue on a small batch of bikes.

All the best, David

 

[Wisper Bikes]

Sorry just read your message in full David. Rutland will do this for you, if you call Adrian he will make sure the parts go out today.

All the best, David

 

[DiggyGun]

Sorry just read your message in full David. Rutland will do this for you, if you call Adrian he will make sure the parts go out today.

All the best, David

Many thanks David, will do.

 

[DiggyGun]

Sorry just read your message in full David. Rutland will do this for you, if you call Adrian he will make sure the parts go out today.

All the best, David

Hi David

Spoken to Adrian and said that he will send the parts out (with a modification) to Rutland Cycling at Milton Keynes today. Please thank him again for us.

Given that we’ve had this problem and the types of riding that we do is mixed terrain; road, cycle paths, bridleways, gravel / dirt tracks, hills, (some steep), would we be better changing the bike for a mid crank motor.

We see that you do the Wayfarer M7 Mid Drive in ”Adventure”, with a choice of two battery sizes.
- Would one of these suit our type of riding better than a hub motor?
- If so, what frame size would be best for Mrs DG who is 1.63m?

We got the 705 in March 2021, in our early days, before we started exploring further afield away from home.