Clutch stuck? motor skipping and not engaging fully

[anfos]

Hi, I have a Giant Stance E+2 with a Yamaha motor (Syncdrive Sport). I removed the chain to clean the chainring, moved it forwards and backwards, today I went for a ride and the motor is skipping/not fully engaging like the clutch is stuck. Is there any way to fix it without opening the motor?

There are no errors reported and running the motor/battery checks through the app gives no error.
To give more details, when I pedal with the motor on it engages for 2 seconds, stops, engages etc.

As I said it happened after moving the chainring backwards and forwards while cleaning it with the chain off, can someone explain why would that make the clutch get stuck and if it's normal?

I also noticed a ton of resistance while climbing with the motor off, like the clutch never fully disengaged which is another reason I tried to see if there is resistance with the chain off.

The bike is new (400km)

 

[anfos]

Applying no pressure at the pedals and the motor works, as soon as I apply a bit of pressure the clutch engages, making the bike stop. Any way to fix this?

 

[anfos]

Here's a video with walk assist, although I keep pressing the button the motor disengages.

 

[The Hodge]

might sound daft but have you checked the back axle is tightened fully ..?

 

[anfos]

might sound daft but have you checked the back axle is tightened fully ..?

It's a quick release, I don't see any issues there. Thanks for the suggestion!

 

[The Hodge]

Check it anyway as mine came loose on a ride and the motor was skipping ..an error code came up on the purion ..but all was well when I tightened the axle ..

 

[anfos]

I managed to fix it! I removed the spoke magnet and without it the motor was working correctly, after a couple of minutes the display unit starts blinking with an error (red) and the motor slows down, so I turned it off and on again - before it displayed the error I added the magnet again and it works fine.

I am guessing it wasn't the clutch but the torque sensor reading the data wrong because I had moved the cranks backwards with the chain off (the motor was not on when I did it though).

 

[Bearing Man]

I managed to fix it! I removed the spoke magnet and without it the motor was working correctly, after a couple of minutes the display unit starts blinking with an error (red) and the motor slows down, so I turned it off and on again - before it displayed the error I added the magnet again and it works fine.

I am guessing it wasn't the clutch but the torque sensor reading the data wrong because I had moved the cranks backwards with the chain off (the motor was not on when I did it though).

I don't know why your motor had a funny five minutes? Very unusual, unless it's still mechanical and comes back later. Just for future reference. The motor needs to see crank speed, crank torque and wheel speed. If you lift the bike and press walk assist, the motor can pulse as some of the parameters it's looking for are missing. If you remove the magnet it will work while it is trying to establish a wheel speed, once the PCB works out there is no wheel speed, the motor will shut down with a speed sensor fault, as yours did.
In your earlier post you mention about a clutch slipping feeling while pedaling without assistance. Your pedals are connected almost directly to your chainring. The only break in that direct mechanical link is the very heavy and very reliable ratchet and pawl system in the back of the front chainring boss. If this part does fail, it is usually a violent affair.
There is a small clutch bearing inside the plastic drive gear but this is not affecting the pedals while the motor is disengaged or off.

I am not saying this is your issue as your bike is quite new, but every time someone has bought us a bike with these sort of symptoms, it has been:

Pawls sticking or breaking up in the rear cassette.
Rear cassette ratchet cracked or breaking up inside.
Rear cassette bearings collapsed.
New chain old cassette or vice versa.
New chain old front chainring or vice versa.
As the hodge said, rear wheel axle loose.
Poor derailleur setting etc.

For anyone reading this that may suffer similar issues, this is best diagnosed by walking next to the bike while someone rides it slowly and watch the chain and cassette, you can normally see issues and hear better where the noise is emanating from.
If you don't have a person available, find an open space with no possibility of riding into something and try to reproduce the noise while your head is turned to the right, you will be better able to distinguish if the noise is coming from the motor area or the rear cassette area.

Glad your all fixed again Anfos

 

[Jackware]

I managed to fix it! I removed the spoke magnet and without it the motor was working correctly, after a couple of minutes the display unit starts blinking with an error (red) and the motor slows down, so I turned it off and on again - before it displayed the error I added the magnet again and it works fine.

I am guessing it wasn't the clutch but the torque sensor reading the data wrong because I had moved the cranks backwards with the chain off (the motor was not on when I did it though).

It looks like you've got two magnets on the rear wheel?

 

[anfos]

Thanks @Bearing Man for the detailed technical post! The issue appeared again and the issue was indeed the double sensor so false alarm lol! I added it because my bryton wasnt picking up the bike sensors but it does now. The bike feels great!

 

[Bearing Man]

Thanks @Bearing Man for the detailed technical post! The issue appeared again and the issue was indeed the double sensor so false alarm lol! I added it because my bryton wasnt picking up the bike sensors but it does now. The bike feels great!

Great spot by Jackware! I must have watched your video 50 times for any movement or issues with the cassette...didn't even notice the other pickup on your wheel! ?‍?