Shimano E8000. Clunk of Death?

[OldGoatMTB]

I E8000 motor has 800 miles on it and seems to have developed a "clunking" noise. It happens when I'm coasting and not pedeling, but when I begin to pedal again the motor makes a clunk as soon as the motor engages, or maybe a fraction of a second after it engages. It's fairly loud and I can hear and feel it. Is this a known symptom? I bought the bike mail order and while there are local Shimano Authorized Service Centers I'm not sure if they have any actual experience with Shimano motors. A couple of them ar Trek dealers and one sells Specialized. Yet another doesn't really do much with ebikes, to my knowledge, so I'm wondering who to turn to. Any advice is appreciated. Thanks.

P.S. The motor is only 5 months old, so still under warranty, fortunately.

 

[Cbmojo]

NORMAL

 

[DrStupid]

Both the DU-8000 drives units I have riden, clunk a little as they engage.

 

[Cbmojo]

Different frames will conduct the noise and vibration a little differently...I have three 8000's and they all do it...carbon frames absorb most of it...totally normal and will subdue a little as time goes on so ride on!

 

[steve_sordy]

I have a carbon framed bike and I have never heard that. I will be looking out for it tomorrow!

PS: I have reduced hearing at certain frequencies, so I may not have heard it for that reason, but I would have thought I would have felt it.

 

[Cbmojo]

It’s more of a feel thing when the play in the freewheel/crank engages the motor there is a brief clunk (clunk is probably overstated because it’s more feel than audible depending on the bike)....they all do it to the best of my knowledge.

 

[OldGoatMTB]

It just seems to have increased in magnitude rather suddenly. Maybe I'm imagining it. At least with 19 months of warranty left I'll either get used to it or it can prove to be something serious. Thanks, all.

 

[steve_sordy]

@OldGoatMTB While I was out today I listened very carefully and heard not a thing, so I forgot about it. Then a bit later on I heard a slight clunk which reminded me.

It happened for me when I stopped pedalling, back pedalled a little, and then pedalled forward again. It is the mechanical parts of your drive train taking up the slack. You get it on your chain and cassette, in your hub, and no doubt in the freewheel inside the motor. It is perfectly normal to have a bit of free movement in the drive train and when you take it up, you can get a slight clunk. Unless it starts to get really loud and is clunking all over the place, I would not be concerned.

 

[OldGoatMTB]

@OldGoatMTB While I was out today I listened very carefully and heard not a thing, so I forgot about it. Then a bit later on I heard a slight clunk which reminded me.

It happened for me when I stopped pedalling, back pedalled a little, and then pedalled forward again. It is the mechanical parts of your drive train taking up the slack. You get it on your chain and cassette, in your hub, and no doubt in the freewheel inside the motor. It is perfectly normal to have a bit of free movement in the drive train and when you take it up, you can get a slight clunk. Unless it starts to get really loud and is clunking all over the place, I would not be concerned.

That's what concerns me, it does seem louder and almost every time I resume peddling.

 

[lightning]

l've got a Kona with Steps 8000 motor and it can feel like there's a clunk as it engages, if you stop pedalling then start again. l guess the motor has to catch up with your pedalling and start to give assistance, and at the point of engagement you are going to feel it.
l found that being a bit more smooth when l start pedalling reduced or stop it from happening.

 

[Cbmojo]

It’s normal...differs depending on drivetrain