Flyon motor internals

Sidepod

Active member
Sep 2, 2020
584
395
Oxford
Long story short, I have a spare motor that doesn’t work. I had no idea why.

Curious to know I dived in.

Easy enough to open. Two sides. The drive side and the electronics side.

The e side is just the 4 torx screws around the centre. Once removed the black section can be pulled off. It’s not immediately easy as it’s held in place by an O ring and the centre seal around the crank. Jiggle it push/pull/tap and it will pop off.

This is where I discovered the problem. It looks as if the ribbon cable connecting the pcb to the torque sensor has been sheared.

Once this side of the motor is open the crank assy can be tapped out from the other side.

Removing the opposite side is a bit more tricky. Remove the 9 (I think?) torx screws and copper washers. Once out it’s a cast of gripping the ribs of the casting and pulling it free. Again the central seal creates friction and again, watch out for the big O ring around the edge.

Once off you have access to the drive unit, the sprag clutch and the bearings.
All of the internals look perfect with zero evidence of water or dirt ingress.

Now I just have to source a new crank assy with torque/cadence sensor or repair the ribbon cable.

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Sidepod

Active member
Sep 2, 2020
584
395
Oxford
Hmmm it’s not really a pcb issue. The ribbon cable has sheared off where it joins the crank assy. The photo of the crank obviously has the connection missing. It would be easy but the short stub of the cable where it disappears inside the black tube of the crank between the bearings is barely accessible.
I’ll need to pop the bearings odd the crank and see it I can get at it.
 

Sidepod

Active member
Sep 2, 2020
584
395
Oxford
Ok so a few more photos.

These hopefully show a bit more of what’s going on.
The slot for the ribbon cable is quite tight when the crank assy gets slid inside the drive unit. I wonder if it has spun and sheared the cable. There doesn’t seem to be too much to locate it.

Anyway the good news is I’ve found the company that make the units so hopefully it’ll be replaceable.




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Technomupet67

New Member
Dec 29, 2020
18
10
London
Long story short, I have a spare motor that doesn’t work. I had no idea why.

Curious to know I dived in.

Easy enough to open. Two sides. The drive side and the electronics side.

The e side is just the 4 torx screws around the centre. Once removed the black section can be pulled off. It’s not immediately easy as it’s held in place by an O ring and the centre seal around the crank. Jiggle it push/pull/tap and it will pop off.

This is where I discovered the problem. It looks as if the ribbon cable connecting the pcb to the torque sensor has been sheared.

Once this side of the motor is open the crank assy can be tapped out from the other side.

Removing the opposite side is a bit more tricky. Remove the 9 (I think?) torx screws and copper washers. Once out it’s a cast of gripping the ribs of the casting and pulling it free. Again the central seal creates friction and again, watch out for the big O ring around the edge.

Once off you have access to the drive unit, the sprag clutch and the bearings.
All of the internals look perfect with zero evidence of water or dirt ingress.

Now I just have to source a new crank assy with torque/cadence sensor or repair the ribbon cable.

View attachment 66968 View attachment 66969 View attachment 66970 View attachment 66971 View attachment 66972 View attachment 66973 View attachment 66974 View attachment 66975 View attachment 66976 View attachment 66977
Ok so a few more photos.

These hopefully show a bit more of what’s going on.
The slot for the ribbon cable is quite tight when the crank assy gets slid inside the drive unit. I wonder if it has spun and sheared the cable. There doesn’t seem to be too much to locate it.

Anyway the good news is I’ve found the company that make the units so hopefully it’ll be replaceable.




View attachment 66985 View attachment 66986 View attachment 66987 View attachment 66988 View attachment 66989 View attachment 66990 View attachment 66991
Thanks for sharing. Good Luck with repairs !
 

Sidepod

Active member
Sep 2, 2020
584
395
Oxford
Any updates on this? 😊
I got nowhere unfortunately. Neither the company that manufactures the crank assy or TQ we’re willing to help.
A bit of a disappointment really. I’ve always found German companies extremely helpful.
I did consider just sending anyway and see what comes back.
Good to see TQ have come out with a new motor recently. Same design principle (strain wave). If it’s a good as the Flyon it’ll be a peach.
 

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