Chain pop

[rodomotion]

Exactly
Mine all are when taking off

same here, but only in the first start of the ride. Had one bearing on the rear hub replaced (not the wheel bearings but the cassete bearing) and the noise is still there, I think is from the chainring area. LEVO 2019, but the newer ones, with all the updates.

 

[DS.]

Chainring area to

 

[Gary]

But maybe "pop" is the technical word ?

No. it isn't

infact... Da fuk's chain pop?

 

[Gary]

I'm now quite convinced clunks are comming from freewheel ...

You do know how a freewheel (Freehub) works, eh?
and you do realise Emtbs have a freewheel mehanism at BOTH ends?

I'm guessing what you're actually hearing and feeling is simply the slack being taken up at both ends when you apply pedalling torque and the (top portion of) chain is loaded from the top of the chainring to the rear sprockets and the motor engages.
It's perfectly normal

 

[Zimmerframe]

You do know how a freewheel (Freehub) works, eh?
and you do realise Emtbs have a freewheel mehanism at BOTH ends?

Nope .. Have you seen the prices of these things, Free is the most inappropriate word they could have come up with

I'm guessing what you're actually hearing and feeling is simply the slack being taken up at both ends when you apply pedalling torque and the (top portion of) chain is loaded from the top of the chainring to the rear sprockets and the motor engages.
It's perfectly normal

This does sound sensible .. and I'll agree with you ... BUT .... ... the noise, which if we're all talking about the same thing, is more of a "clunk" like a really bad gear change, as you feed in the power hard (which is relative, on Blevo, for human power .. mine just shows a laughing "smiley")

For me the oddest thing is that since changing to tubeless .. mine has completely stopped doing it .. not once .. never .. not a clunk.

 

[Gary]

Have you seen the prices of these things

A tenner? (Shimano Freehub body) Are you also part Scot?
perhaps a single speed FREEwheel would suit you better (@£4.99)

since changing to tubeless

tubeless fucking ruined my day both yesterday and today.

ying* and yang mate

*Scottish pronounciation

 

[Zimmerframe]

A tenner? (Shimano Freehub body) Are you also part Scot?
perhaps a single speed FREEwheel would suit you better (@£4.99)


tubeless fucking ruined my day both yesterday and today.

ying* and yang mate

*Scottish pronounciation

£4.99 Extortionate ! You can buy .. I dunno .. not much, got stung €15 for a takeaway burger at lunch today. OK .. stick with Freehub then..

Tubeless toilets .. they're crap.

 

[salko]

Well now after my last LBS visit I got maybe 1 more clunk and now I have done about 300km without a single clunk so I guess this annoying issue healed itself ?

 

[Kave]

Same with mine, chain, chainring and casette have adapted so no more chain slip.

 

[Murch]

Mine seems to have calmed down as well, I only hear it maybe once a ride if that. I did put a new chain on at 500 miles so not sure if that helped or not.

 

[GrandPaBrogan]

You do know how a freewheel (Freehub) works, eh?
and you do realise Emtbs have a freewheel mehanism at BOTH ends?

I'm guessing what you're actually hearing and feeling is simply the slack being taken up at both ends when you apply pedalling torque and the (top portion of) chain is loaded from the top of the chainring to the rear sprockets and the motor engages.
It's perfectly normal

I'm not sure if this has anything to do with the issue being referred to here as 'chain pop' but just in case it's related... Gary has a point. I'll expound it a bit further, if I may.

As previously mentioned, there ARE two ratchets on an eBike - one at the wheel cassette and one at the BB axle of the motor. It doesn't matter how many teeth there are, sometimes we can pedal at a spot where the pawls have to first travel across a gap between teeth before it can 'drop-in' - to engage (which is why super expensive racing hubs have more teeth and more pawls to minimise this mechanical lag). More often than not, the pawls just so happen to be already engaged when we pedal - and so we don't even notice this lag.

But on an eBike, we have two ratchets... and the one in the motor may have less teeth (stronger). Just imagine every once in a while, that the pawls of both ratchets may happen to be unengaged when we start to pedal/accelerate. The combined mechanical lag of both ratchets engaging in-sync will, a) cause the crank arms to travel a longer distance than usual before both the ratchets engage, and b) when they do, it'll make a louder than usual clunk or pop sound.

This may not be the 'chain-pop' some of you guys are experiencing, but all eBikes will have this characteristic to some extent (with the exception of motors with one-way clutch bearings on the BB axle which are step-less).

 

[wepn]

I'm not sure if this has anything to do with the issue being referred to here as 'chain pop' but just in case it's related... Gary has a point. I'll expound it a bit further, if I may.

As previously mentioned, there ARE two ratchets on an eBike - one at the wheel cassette and one at the BB axle of the motor. It doesn't matter how many teeth there are, sometimes we can pedal at a spot where the pawls have to first travel across a gap between teeth before it can 'drop-in' - to engage (which is why super expensive racing hubs have more teeth and more pawls to minimise this mechanical lag). More often than not, the pawls just so happen to be already engaged when we pedal - and so we don't even notice this lag.

But on an eBike, we have two ratchets... and the one in the motor may have less teeth (stronger). Just imagine every once in a while, that the pawls of both ratchets may happen to be unengaged when we start to pedal/accelerate. The combined mechanical lag of both ratchets engaging in-sync will, a) cause the crank arms to travel a longer distance than usual before both the ratchets engage, and b) when they do, it'll make a louder than usual clunk or pop sound.

This may not be the 'chain-pop' some of you guys are experiencing, but all eBikes will have this characteristic to some extent (with the exception of motors with one-way clutch bearings on the BB axle which are step-less).

View attachment 21687

Excellent explanation! An engineer

 

[McInner1]

But the „ratchet“ inside the brose motor can‘t produce a „clonk“.
It consists of rubber blocks that lock in one direction.

from video (at 1 min)

 

[Mr CRUD]

No Clunks or Pops on my Shimano 8000 setup after 1,200 km. Still as sweet as new, and also no play in the crank. And I run it on turbo mode 90% of the time. I'm sure other systems are good, but I will stick with what I know.

Took the side cover off yesterday. Absolutely caked in mud from 6 months of abuse-neglect, and still working perfectly. 2-minute job to clean it up.

 

[wepn]

But the „ratchet“ inside the brose motor can‘t produce a „clonk“.
It consists of rubber blocks that lock in one direction.

from video (at 1 min)
View attachment 21724

Yes true but it was still an engineer’s explanation - of a slightly different motor

The clunk did sound hollow to me which makes me think it’s the same principal but potentially driveshaft - BB engagement.

 

[salko]

Well now after my last LBS visit I got maybe 1 more clunk and now I have done about 300km without a single clunk so I guess this annoying issue healed itself ?

Today I experienced another chain pop/clunk, and this is now after about 80kms from installing brand new PC-X1 chain (different than stock chain which is KMC). So I guess it is not the chain which clunks ...

 

[brizi2003]

2019 levo
About 2-3 times per ride as I take off I hear what I believe is a single chain pop.
Bike shifts OK ??
Any ideas?

Thanks in advance
Mcg

Did you get to the bottom of this - I'm experiencing soething similar - sounds all the world like a freehub pawl click but seems to come from the motor.

 

[gaba]

I’ve had an intermittent pop sound since I bought the bike . Finally had my hub fail after a pop on a steep climb . I’m convinced now that the hub slipping was the sound all along. The carbon Roval wheel/DT Swiss hub is off the bike while I warranty the wheel. No pops at all with the Industry9 wheel that’s on there now after 6 rides.

 

[Utah Rider]

It's normal. It's the chain on the front chain ring. It will go away as the chain stretches. I wouldn't worry about it. I have two Levos over 3 yrs old. They all do it.

 

[Murch]

My motor gave out a couple of weeks ago and just before it did I heard two chain pops but just a bit louder. I stopped the bike and looked down to see if I could see anything but didn't notice a thing. I went to start back on my ride and when I applied power to the pedals there was a gear slipping sound and no power coming out of motor just the slipping sound. I was able to pedal out of the trail under my own power which was good but no assist from the motor.

The sound of the popping was the same just a bit louder, I am not sure if the sounds are related but after getting my new motor and riding it yesterday I had zero chain pop sounds the whole ride.

 

[cozzy]

Yes my 2019 kenevo does this. Its not the rear hub, as it did it on stock wheels & the reserve wheels currently. Feels like the chain is jumping, but unlikely due to the small mileage I have done so far.
My worry was the sprag/freewheel/whatever clutch in the motor slipping, but it sounds like its just one of those things after reading the above.

 

[Deleted member 7464]

Could also be the freehub, they sometimes make a loud 'crack' from time to time when they are sticking a little. This normally occurs when just starting to pedal. Maybe try stripping the rear wheel freehub and cleaning & lubricating as per recommended for this type of freehub.

Mine did it at the weekend and I would say its def the freehub. Its just one of the pawls locating properly.

 

[gaba]

Mine did it at the weekend and I would say its def the freehub. Its just one of the pawls locating properly.

Beware. That’s how mine started. I’d pull it apart clean and relube it. Use only DT Swiss hub grease. Mine failed fully on a steep climb a few weeks back. Using a spare wheel with an I9 hub while I wait for a replacement. (Hopefully a warranty). No chain pop sound anymore at all.