Como 2.0 chain slap/derailleur tension

ta373

New Member
My wife has a 2018 Como 2.0 stepthru that we’re seeing some new behavior with.
  • It seems to have lessened the strength of power delivery (noticeable on hills)
  • It has a mechanical clicking sound coming from the front chain ring (the one attached to the pedals)
  • The chain seems to go slack every so often
  • The rear derailleur seems to pull forward towards the front of the bike - allowing the chain to go slack
The bike still hits the 19.5-20mph top speed, but seems more sluggish in acceleration.

She did get the chain replaced recently at a non-ebike shop, and she hasn’t yet gotten the motor firmware update.

Does this sound mechanical, or electronic/motor related?
 
My wife also has a 2018 Como 2.0 step through and I think we had the same issues you’re experiencing. Unfortunately, we didn’t listen to our gut and kept riding it. The LBS said it was something called “chain suck” where the chain doesn’t “let go” of the front sprocket and it gets ‘sucked‘ around and if it goes all the way around it will run into the chain on the top. It pulls the rear derailleur, it slaps the bike frame when it releases. For her, it ended with the motor making a horrible grinding noise and the peddles stopped rotating. On the bike rack it went to the LBS for diagnosis. It was covered by Specialized who replaced the front sprocket, chain, and labor to fix it. We think it’s OK now, but the cold weather came and we haven’t be able to give it a good work out yet.
 
My wife has a 2018 Como 2.0 stepthru that we’re seeing some new behavior with.
  • It seems to have lessened the strength of power delivery (noticeable on hills)
  • It has a mechanical clicking sound coming from the front chain ring (the one attached to the pedals)
  • The chain seems to go slack every so often
  • The rear derailleur seems to pull forward towards the front of the bike - allowing the chain to go slack
The bike still hits the 19.5-20mph top speed, but seems more sluggish in acceleration.

She did get the chain replaced recently at a non-ebike shop, and she hasn’t yet gotten the motor firmware update.

Does this sound mechanical, or electronic/motor related?
How many miles on your ebike?

What has been you chain maintenance routine during these miles?

Any other maintenance, upgrades?
 
New chain recently, plenty of goop on the derailleur that could be cleaned off. Other than that just new brake pads. Chain came from a non-ebike shop.
 
New chain recently, plenty of goop on the derailleur that could be cleaned off. Other than that just new brake pads. Chain came from a non-ebike shop.
It would still be helpful to know how many miles are on the bike, esp since it has the original cassette and chain ring.

With that said I would suggest you verify that the chain was installed correctly on the wide-narrow front chain ring. It matters which teeth mesh with the different chain slots.

Sounds like the derailleur needs a good cleaning and a lube job. This post discusses one approach to this; 'Changing gearing on my Vado 5' https://electricbikereview.com/forums/threads/changing-gearing-on-my-vado-5.38756/ .

The cassette and front chain ring should also be cleaned periodically. This post discusss one approach to cleaning the cassette; 'Specialized Turbo Vado/Como User Club' https://electricbikereview.com/foru...d-turbo-vado-como-user-club.31893/post-282968
 
I'd also add that the Como/Vado 2.0 bikes are spec'd with a non-clutch derailleur (to keep costs low) which results in more chain slap that you're experiencing. Should the issue persist I'd suggest upgrading the rear derailleur and shifter to a Microshift Advent 9s shifter/derailleur. It's 9 speed so it'll work with your chain and cassette just fine, but gives you the clutch function effectively ridding you of the chain slap. Those parts weren't originally on the bike as they only came to market recently.

A clutch system on a rear derailleur was born from the 1x drivetrains, essentially it's a much stiffer spring on the derailleur cage thus keeping the chain more taught to prevent the chain from jumping off the front chainring.
 
Thanks for the replies all - sorry to be short on details earlier. Coming up to speed slowly and didn't honestly know enough to know what was important. I really appreciate the attention and effort!

The ODO shows 1795. Not sure if the chain is mounted correctly, or if the entire setup is excessively dirty.
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Hmmm... Perhaps you could clean the chain first? :) The rule is: WIDE tooth in NARROW (inner) chain-link. NARROW tooth in the WIDE (outer) chain-link. It is hard for me to see anything in these pictures. The chain should be often degreased and oiled... and that's the rule #1. You cannot expect smooth operation of the drive-train without having it maintained.
 
She did get the chain replaced recently at a non-ebike shop, ...
Does this sound mechanical, or electronic/motor related?
Can you provide a picture of the chain from the side?
Do you know brand and model of the new chain (is it Shimano xxx or KMC or ?)
 
Thanks for the replies all - sorry to be short on details earlier. Coming up to speed slowly and didn't honestly know enough to know what was important. I really appreciate the attention and effort!

The ODO shows 1795. Not sure if the chain is mounted correctly, or if the entire setup is excessively dirty.
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The chain ring has a graphic on the side towards the bike that shows the proper chain installation on the wide/narrow tooth pattern;

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What maintenance had you been doing to the original chain? I clean and lube my Vado 5 chain every 250-300 miles. I assume the ODO reading is in miles since you're from WA state? If you'd been doing similar chain maintenance your chain ring is probably OK at ~1,800 miles. If not, as @STSKIDMORE mentioned, you may need a new chain ring along with the new chain. If your issues started after the new chain install this would be further indicative of chain ring wear.

BTW - A firmware update would be a good idea. A Specialized dealer needs to do this.
 
Are you sure about that orientation? Can't recall that graphic on my chainring or on others I've seen.

Here's what I was taught from most MTB, basically the opposite. Wide tooth on the outer link, narrow tooth for narrow link.
 

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Are you sure about that orientation? Can't recall that graphic on my chainring or on others I've seen.

Here's what I was taught from most MTB, basically the opposite. Wide tooth on the outer link, narrow tooth for narrow link.
I am sure about the graphic I posted. Both of our Vado 5s have this. Others have posted pics about this as well. It's a bit hard to see as it's on the bike side of the chain ring and is only visible once per revolution from a restricted position. I need a flash light to see it, but then I need a flash light to see a lot of things anymore!

It is opposite from what I thought I knew as well.
 
I am sure about the graphic I posted. Both of our Vado 5s have this. Others have posted pics about this as well. It's a bit hard to see as it's on the bike side of the chain ring and is only visible once per revolution from a restricted position. I need a flash light to see it, but then I need a flash light to see a lot of things anymore!

It is opposite from what I thought I knew as well.
Interesting, thanks for the insight! Time to check my bike too...

I will say that the folks I've sold Vado/Como product to have yet to have chain slap/dropping issues. For whatever that's worth. I've had folks with Bosch motors have issues though. Not from the motor, but from the fact that the brands didn't spec narrow/wide chainrings nor clutch derailleurs.
 
Narrow chains require tighter tolerances. Check your derailleur sprockets. A lot of times there is enough buildup that it starts to stick or cause the derailleur sprockets to not spin freely and the arm tightens then releases (slapping). Slap often happens when the chain does not flow over the cogs, derailleurs sprockets and chainring, evenly and freely. Torque, acceleration are secondary circumstances.

Also note the type of lubricant you are using, some will pick up a lot of grime quickly, in as little as 50 miles on dusty roads. All that being said, that specialized chain and chainring certainly sounds suspect, no pun intended.;)

Clutched derailleurs are a good thing BTW.
 
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I don't think Praxis could be wrong with this diagram...

Narrow-Wide Chainring Diagram.jpg


There are more points to consider:
  1. The engravings on the chain shall point outwards
  2. If the chain is directional, an engraved arrow shows the rotation direction.
 
The rule is: WIDE tooth in NARROW (inner) chain-link. NARROW tooth in the WIDE (outer) chain-link. It is hard for me to see anything in these pictures.
Are you sure about that orientation? Can't recall that graphic on my chainring or on others I've seen.

Here's what I was taught from most MTB, basically the opposite. Wide tooth on the outer link, narrow tooth for narrow link.
@Stefan Mikes
no, it's exacly the opposite: wide tooth in wide chain-link. It doesn't make any sense to set that in the narrow link as that would destroy the chain over time.
@Brendon@TBSM 's picture shows the right way of mounting.

So here we have the wording confusion again, I thought it was solved. Please look at the picture
and notice: which tooth is which is to be judged from the top (and wide is from side to side), not from the side of the chain!
 
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@TS25: I thought the diagram is at the correct tooth? Depicting the outer link on the narrow tooth?
P.S. Never mind. I understand: from the top. So the diagram is correct. I thought we judge it from the side.
 
After reading this thread I had a look to my Vado 3 and Como 5 (my girl friends bike) because yesterday I cleaned the chains and both chains slipped off the chain ring during pulling the chain backwards. Then I put the chain back on the chain ring without knowing the here discussed topic. This morning I had a look and noticed the following: first off only the Como had the grahphic inside the chain ring but not the Vado 3 although it's a NW chain ring. Then I tried to move the chain back by one tooth and noticed that this is not possible. Both bikes have still the original chain, chain ring and derailleur.
 
Some more pictures illustrate the difference between Deckas chainrings and Specialized (Praxis) chainrings.
I have marked the narrow tooth in a red and the wide tooth in a yellow frame.

It is noticeable that the Deckas chainring has the clearly better narrow-wide structure of the chainring teeth which I also felt riding after changing to the Deckas chainring. The chain runs - how shall I call it - more linked to the chainring and there is no looseness/slackless moment to be felt at any time.
 

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