ebike not outputting more than 30 watts and motor slowing me down when activated

[james nichols]

so my zipper z6 emtb began limiting my speed, i could pedal with assist up to 15.5mph and then continue to pedal to higher speeds by myself. then all of a sudden one day as i reached 19-20mph my motor would begin to act like a brake, slowing me down so that i could not with any more effort go over that top speed.

this has gone on for a few months, during that time i began hearing some sort of scraping sound while i was pedaling but not when i wasn't.

just the other day, on a fully charged battery, i lost pretty much all of my output, the display shows me that it is not able to go much over 30watts output. every time i begin pedaling, the motor brakes me, slowing me down more before getting back up to 30 watts which is really no help at all. right now i have an e bike that prevents me from reaching even 15mph.

can any body understand my situation?

 

[Deleted member 4366]

The controller sits in that box on the seat-post. Open it up and check all the motor connectors. I'm going to guess that the three motor phase wire connectors are melted. Whatever, pull all the connectors out in the open so that we can see what you've got.

 

[james nichols]

The controller sits in that box on the seat-post. Open it up and check all the motor connectors. I'm going to guess that the three motor phase wire connectors are melted. Whatever, pull all the connectors out in the open so that we can see what you've got.

ok, so i broke into my controller box, checked all the connections and not a single sign of any moisture or burns or any such defect so that stage is out of the question.

what next?

 

[Deleted member 4366]

If they're the bullet type, pull them apart, crimp them down a bit and push them back in.

Does the motor spin freely forwards? Does it feel normal when you turn it backwards?

 

[james nichols]

If they're the bullet type, pull them apart, crimp them down a bit and push them back in.

Does the motor spin freely forwards? Does it feel normal when you turn it backwards?

all wiring is sound at the control box.

i believe the problem is in my motor. it definitely feels clunky to the turn. it scrapes and clicks and is quite literally a drag. unfortunately, i dont have the tool to take off my rear cassette to get at the motor so im going to order one. unil then i did all else i can, i traced my way to the front instead and took apart the computer display. i did find some areas that looked water damaged but nothing burnt out so i cleaned that down and the problem remained.

im just sure its the motor now

 

[Deleted member 4366]

Try disconnecting the motor from the controller. Many of these types of problems can be caused by the controller. If it stays the same, the problem is in the motor. If it changes, the problem is in the controller.

 

[james nichols]

Try disconnecting the motor from the controller. Many of these types of problems can be caused by the controller. If it stays the same, the problem is in the motor. If it changes, the problem is in the controller.

i believe i have finally found out what the problem is.

it is most certainly a phase wire issue. i heard reports that a short with these 3 wires will effectively turn the motor into a brake and make it very hard to rotate. this is exactly my problem.

as i already checked all the visible cables as well as inside the controller box and found no signs of damage or contact, my only other option is inside the motor itself. unfortunately, i couldnt get to it because i didnt have a freewheel removal tool. i did order one, it has arived and to my displeasure, the whole through the tool is not wide enough by maybe a mm to fit over my rear axle to slide down to the cassette.

 

[awol]

the whole through the tool is not wide enough by maybe a mm to fit over my rear axle to slide down to the cassette.

I had the same problem and it's wasn't easy drilling out, nearly melted the drill bit. Maybe dremmeling it out with a small grind stone might have been easier.

 

[james nichols]

I had the same problem and it's wasn't easy drilling out, nearly melted the drill bit. Maybe dremmeling it out with a small grind stone might have been easier.

drilling wasnt my first thought...

i jumped in my kitchen draw for the steel knife sharpener and tried using that but to no avail. after an hour, then i thought, how about getting the drill out? of course it was too late now, as my son had just gone to bed so im left waiting for tomorrow

 

[james nichols]

I had the same problem and it's wasn't easy drilling out, nearly melted the drill bit. Maybe dremmeling it out with a small grind stone might have been easier.

i might actually be able to get a dremmel on it if i take it to work in th morning. good idea

 

[Deleted member 4366]

If the motor is difficult to turn when disconnected, the problem is in the motor or its cable. If it's only difficult to turn when connected, the problem is in the controller or its cable.

 

[mike killay]

 

[james nichols]

the situation is frustrating.

i have gotten to the freewheel with the tool but now it is impossible to remove. it is far too tight. i have no metal tube to extend my wrench arm. any ideas for household things that can assist me in turning this thing?

... no vice.

 

[VictoryV]

the situation is frustrating.

i have gotten to the freewheel with the tool but now it is impossible to remove. it is far too tight. i have no metal tube to extend my wrench arm. any ideas for household things that can assist me in turning this thing?

... no vice.

Have you tried penetrating oil on the part with an overnight soak

 

[mike killay]

the situation is frustrating.

i have gotten to the freewheel with the tool but now it is impossible to remove. it is far too tight. i have no metal tube to extend my wrench arm. any ideas for household things that can assist me in turning this thing?

... no vice.

Try a hammer, or using strong cord tie a piece of wood (broom handle etc.) to the wrench. Also, boiling water, a towel draped over the too tight part can loosen things.

 

[awol]

A few weeks ago I had one which was stuck solid and snapped my chain whip tool and I nearly ended up pulling my vice off the bench so ended up using a hammer and pin punch as shown at the start of the previous video. First was to remove the screw part he shows, but mine also had a small thing under that which I could tap around again, just a small bit at a time.
Mine was brand new, the reason mine was so tight was the thickness of paint on the motor threads and a cheap rubbish freewheel.

 

[Deleted member 4366]

The easy way to get the freewheel off is to put the tool in a vice and turn the wheel.

If you don't have a sturdy vice, then you need a long spanner and a lump hammer.

Awol, you must have been doing something wrong. you don't need a chain-whip for a freewheel. In fact it's more or less impossible to remove the freewheel if you use a chain-whip.

 

[awol]

Awol, you must have been doing something wrong. you don't need a chain-whip for a freewheel. In fact it's more or less impossible to remove the freewheel if you use a chain-whip.

Just been to look at a spare freewheel and your right, I was using the force of the removal tool against the force of the chain whip, held in a vice. No wonder it snapped.
The freewheel was stuck on a motor not yet built into a wheel so I was in a right panic and thought that was the only way to stop it spinning on the motor, am glad you just pointed that out, good info for the future.