Myth BUSTED: "The Chain Drops On My Specialized E-Bike Because The Chainring Is Praxis WAVE"

[pete H]

I continue to have the same issue with the chain coming off. I put about 6,600 miles on the 2022 Vado 5.0 in 16 months, replaced the chain every 1500-2000 miles, new cassette at the same time and it eventually happens, many, many times. Discussed it with the local bike shop Guru, and he experienced same issue with his Vado when he had one. His opinion makes sense. He, like I, do a lot of upshiting and downshifting and when coming to a stop and downshifting and upon eventually stopping, it's like the internals of the motor are still slightly spinning and that ever so slowly puts the chainring out of sync with the chain. You should notice that it is usually when starting from a dead stop, and had just downshifted prior to stopping. Upon stating off again, the chain is popped off of the chainring. Seems like a common problem with a lot of solutions. I may consider the Garbaruk chainring next time. I always use the KMC e11 chain, and I always wax the chains (hot wax dip).

Reading your post you have identified the times the chain pops off exactly as it happened to me. Unfortunately this doesn't explain why this only happens to some of us and not others. My LBS has identified the problem and emailed Specialized but has not had any response.
To reinforce what you are saying, i have a narrow/wide chainring replacing the OEM wave. When starting off sometimes there is definitely a clank sound which i think is the wide tooth gripping the chain and locking it on to the chainring.
Just my theory

 

[pete H]

Reading your post you have identified the times the chain pops off exactly as it happened to me. Unfortunately this doesn't explain why this only happens to some of us and not others. My LBS has identified the problem and emailed Specialized but has not had any response.
To reinforce what you are saying, i have a narrow/wide chainring replacing the OEM wave. When starting off sometimes there is definitely a clank sound which i think is the wide tooth gripping the chain and locking it on to the chainring.
Just my theory

So unfortunately i tipped off today after being overtaken by a quad bike at speed in a country lane on a hill. Front wheel went off the road into a gap at the side and i landed on the right side. The rear derailleur took a bang and was bent in. So i pulled it as straight as i could and even though the gears were a bit sketchy NO chain drop on the 20 miles back home! I have to say that is down to my narrow/wide chainring. I wouldn't have fancied my chances with the Praxis ! Off to LBS tomorrow for a new hanger and to get gears indexed.

 

[GuruUno]

So OK, Stefan seems to have the most experience and knowledge regarding these types of issues. I regard his opinions as the rule to follow, most times. If anyone know things, he seemingly knows a lot from his experimenting and experiences (with the e-bike stuff).
That being said, I'll pose this set of questions and hopefully Stefan you can blueprint the path to follow, for some of us (others may have alternate needs depending on various factors).
Other than those occasional chain drops I have, the only other item with gearing that I have is that 'sometimes' I'm curious if there would be any benefit to changing things up with different chainrings, cassettes, chains, etc.
So, Stephan, on the Vado "Big Boy" (6.0/5.0), what would YOU from all of your experimenting say is the 'perfect' configuration for the majority of riders?
I understand that it might be a difficult question given everyone has different riding habits and terrain where they ride, so I'll just say 'majority' meaning a semi-universal pairing of components that make most of us happy.
I've read some of your previous in depth postings with a plethora of information, but my digestive capabilities are overloaded and was hoping to get the "Reader Digest" version......

 

[Stefan Mikes]

So, Stephan, on the Vado "Big Boy" (6.0/5.0), what would YOU from all of your experimenting say is the 'perfect' configuration for the majority of riders?

There is no "perfect" configuration. I used to own as many as four different e-bikes and did not experience chain-dropping issues as long as:

• The chain was properly engaged on the chainring (one of the e-bikes I own has a 3x drivetrain where there is even no "narrow wide" possible!)
• The derailleur is properly indexed with the limit screws properly set
• The derailleur hanger is straight
• The derailleur chain tensioner is on (if present)
• The chain is properly connected, clean, unstretched and lubed
• The chainring or the cassette sprockets are not worn.

The Narrow Wide or WAVE pattern is there just to help to keep the chain on the chainring despite severely skewed chain line on 1x derailleurs. Do you think Garbaruk makes Narrow Wide 1x chainrings? I do not think so. The Garbaruk "patent" is to make oversized (very long) chainring teeth; it is less probable the chain would drop with such long teeth. The chain drop might happen on any chainring it two neighbouring chain links get stuck on the roller.

If you want to intentionally simulate a chain drop on a classical 3x drivetrain, just keep the chain on the largest chainring sprocket but in the largest cassette cog and pedal hard. That was how a friend destroyed my new derailleur and bent the derailleur hanger on my brand new first e-bike...

Yes, there is a situation of chain dropping: a MTB with a small 1x chairing and you do a jump from 2 metres The chain will jump and might drop. That's why good MTBs are equipped with a chain guide to prevent the chain dropping.

I would think the chain drop on any of your advanced Specialized e-bikes might be attributed to anything else but not to the Praxis WAVE pattern that is there to help you not to do any harm to you.

For instance: The new Vado SL 5.0 is equipped with a SRAM X-SYNC chainring, which is definitely not a Praxis Wave one. Anyone of you being an owner of a Vado SL with the X-SYNC chainring?

 

[Jimbo08]

Only ever had one customer with a Praxis issue on a Creo. Put on the little chain guide and no further problems.
Changed my cassette to 11-38 or 11-40 on my 2020 Vado 5.0 because I never used the granny gears much. big hills on my commute both ways, but I tend to use Turbo mode for those. Replace my chainring and cassette at about 2000km, and a new chain every 500km, whether it needs it or not. Because I own 3 ebikes none of them gets particularly high mileage.

 

[gpburdell]

Do you think Garbaruk makes Narrow Wide 1x chainrings? I do not think so.

They show it on their website.

Are you suggesting that they ship something different than the advertised and pictured narrow-wide tooth pattern?

 

[Stefan Mikes]

Could you check it for the

They show it on their website.

Are you suggesting that they ship something different than the advertised and pictured narrow-wide tooth pattern?

View attachment 164389

View attachment 164387

No, they make what they advertise. When I was installing my two latest Garbaruk chainrings, I even did not pay attention how I was placing the chains on those two chainrings, as a person must be totally inexperienced to place the chain the wrong way...

 

[boxrick]

I was having constant chain drop issues with my Praxis chainring at least 1 or 2 a day. Swapped it to the Gabaruk one and I've not had a single drop in months.

 

[gpburdell]

Could you check it for the

No, they make what they advertise. When I was installing my two latest Garbaruk chainrings, I even did not pay attention how I was placing the chains on those two chainrings, as a person must be totally inexperienced to place the chain the wrong way...

On a proper narrow-wide chainring such as the Garbaruk and Wolftooth, you don't need to pay attention since the chain won't really fit the wrong way - the narrow chain gaps won't go onto the wide teeth.

 

[pete H]

On a proper narrow-wide chainring such as the Garbaruk and Wolftooth, you don't need to pay attention since the chain won't really fit the wrong way - the narrow chain gaps won't go onto the wide teeth.

Correct it is not possible to put the chain on wrong.