Question on 'dropped chain'?

[freewheeling]

@freewheeling thanks for the info on the Vado SL setup, I've not had a chance to look at it in person.

I've seen the BBG and a couple others such as FSA. Thanks.

I'm hoping someone's already ridden down this path and has some insights to offer before I spend the money on something, or perhaps I'll be the first one to do so.

I note the BBG and others would sit between the chainring and spider, shifting the chainring inward by the guard's thickness. I'll need to measure to see if there may be clearance issues bringing the chainring 3mm closer to the frame, especially if something like a Wolftooth chainring is thicker than the OE Praxis. (plus would need thicker chainring bolts of course)

Yeah, I'm in the same boat. But the opposite way having a Vado. It's a bit of a nightmare trying to figure out. There are so many different sizes, standards and designs, which is made more challenging with the complication of the SLs Motorized crank. It'd be helpful if Specialized offered with or without chain guard accessory options for both bikes.

 

[Stefan Mikes]

The Vado's chainring guard is made of plastic and screws into special holes in the Praxis Chainring.

That is the special solution of Praxis used not only for Vado SL but also on the bigger Specialized e-bikes such as Vado or Como. The Praxis spider holes are threaded, so it is possible to fasten the chainring only using the hex wrench from the outside. The reason is a very tight clearance between the chainring and the frame/motor, making it difficult to use any nut from the inside. The bashguard is connected by small screws from inside of the chainring, so installing the bashguard is done with the chainring off the bike.

Since I started modding my big Vado (the original chainring was 48T/Praxis/bashguard -> 38T steel Shimano for mountains -> 42T alloy Garbaruk for the plains), and I had to use regular 8x8mm MTB chainring bolts with nut, I gave up the bashguard completely.

No issues like a dropping chain and in a rare case of riding in jeans I do the "sock thing".

 

[lilchris]

I have had the chain come off on my Specilaised Vado 3 step through, the first time I was manouvering the bike in my back yard ie pulling the bike backwards and the chain jammed behind the front chainwheel. It happened again last week when I was doing something similar while out riding, this time I noticed straight away so I laid the bike on it's side, it was not jammed has badly, and I managed to put the chain back on, ended up with dirty hands....lol. Somebody mentioned getting a chain guide which I have off Amazon. Thinking about it I am not sure if this will work because like I said my chain as only come off when moving the bike backwards, I now try to lift the back wheel in my back yard. The bike is nearly new, only bought in Febuary and I did not get to ride it much at first with the weather we have had over here in the uk. The only other problem I have had is one day the bike went in stealth mode, I had to go to the dealers and they re set it for me and did the latest firmware update on the bike. The thing was when it happened my mobile phone with the app was in my pocket. Chris.

 

[kahn]

I have had the chain come off on my Specilaised Vado 3 step through, the first time I was manouvering the bike in my back yard ie pulling the bike backwards and the chain jammed behind the front chainwheel. It happened again last week when I was doing something similar while out riding, this time I noticed straight away so I laid the bike on it's side, it was not jammed has badly, and I managed to put the chain back on, ended up with dirty hands....lol. Somebody mentioned getting a chain guide which I have off Amazon. Thinking about it I am not sure if this will work because like I said my chain as only come off when moving the bike backwards, I now try to lift the back wheel in my back yard. The bike is nearly new, only bought in Febuary and I did not get to ride it much at first with the weather we have had over here in the uk. The only other problem I have had is one day the bike went in stealth mode, I had to go to the dealers and they re set it for me and did the latest firmware update on the bike. The thing was when it happened my mobile phone with the app was in my pocket. Chris.

I really don't think a chain should pop off merely rolling the bike backwards or even back pedaling. I think a shop should take a look at it and check chain length and alignments.

 

[Stefan Mikes]

I really don't think a chain should pop off merely rolling the bike backwards or even back pedaling. I think a shop should take a look at it and check chain length and alignments.

Well, kahn... @lilchris made an interesting observation! While back-pedalling does not take any effect (as the cranks are not connected to the chainring), rolling the e-bike backwards does move the chain, and the chain drop becomes quite probable! It is because rolling the bike backwards sets the cassette cogs in motion, and the cassette cog becomes your "reverse chainring". The actual chainwheel has no sideways movement limiter screws (present in the derailleur), so...

 

[freewheeling]

I have had the chain come off on my Specilaised Vado 3 step through, the first time I was manouvering the bike in my back yard ie pulling the bike backwards and the chain jammed behind the front chainwheel. It happened again last week when I was doing something similar while out riding, this time I noticed straight away so I laid the bike on it's side, it was not jammed has badly, and I managed to put the chain back on, ended up with dirty hands....lol. Somebody mentioned getting a chain guide which I have off Amazon. Thinking about it I am not sure if this will work because like I said my chain as only come off when moving the bike backwards, I now try to lift the back wheel in my back yard. The bike is nearly new, only bought in Febuary and I did not get to ride it much at first with the weather we have had over here in the uk. The only other problem I have had is one day the bike went in stealth mode, I had to go to the dealers and they re set it for me and did the latest firmware update on the bike. The thing was when it happened my mobile phone with the app was in my pocket. Chris.

What you describe as "moving the bike backwards" is a standard use case of any general-use bike. I may have recreated the same circumstances while testing my bike on my maintenance stand. But I am not 100% sure so please no flames. I found that the chain needed to be located on the Praxis chainring exactly how the "white" diagram on the inside of the chainring directs (See photo below). It could be worth a check and investigation.

 

[Stefan Mikes]

What you describe as "moving the bike backwards" is a standard use case of any general-use bike. I may have recreated the same circumstances while testing my bike on my maintenance stand. But I am not 100% sure so please no flames. I found that the chain needed to be located on the Praxis chainring exactly how the "white" diagram on the inside of the chainring directs (See photo below). It could be worth a check and investigation.

If someone places the chain on the wrong teeth of the Narrow-Wide or Praxis Wave chainring, then the chain starts skipping (not dropping) immediately!

 

[freewheeling]

If someone places the chain on the wrong teeth of the Narrow-Wide or Praxis Wave chainring, then the chain starts skipping (not dropping) immediately!

Exactly Stefan. But the skipping in combination with the chain going backwards causes the chain to drop. I've tested it on a Vado 4.0 with the standard Praxis chain ring that it came with.

 

[Stefan Mikes]

Exactly Stefan. But the skipping in combination with the chain going backwards causes the chain to drop. I've tested it on a Vado 4.0 with the standard Praxis chain ring that it came with.

Yes. I do not deny it! As I said "there are no limit screws on the chainwheel"
Although I must say the chain has never dropped with me occasionally moving my e-bikes "in the reverse"!

 

[freewheeling]

Yes. I do not deny it! As I said "there are no limit screws on the chainwheel"
Although I must say the chain has never dropped with me occasionally moving my e-bikes "in the reverse"!

Stefan, You strike me as a person that knows the trick of placing the chain on the chainring in accordance with the maker's specification. It's more obvious with narrow-wide chainrings. But I found that the design of the Praxis wave tooth pattern allows one to incorrectly place the chain, which is presumable why Praxis print the guide in white. In my experience, both the Praxis and narrow-wide chainrings allow the Vado to be moved in reverse without dropping the chain.

Or put another way, it's worth checking how one's chain is placed on the chainring. If only to discount this as a potential problem, particularly if you have a wave pattern Praxis Chain Ring.

 

[Stefan Mikes]

Hmm... When you place the chain on the chainring, just look at the chainring and chain from the top. It soon becomes obvious what the correct pattern is. The diagram on the inner side of the chainring makes the operation a no-brainer but the experience comes fast. (Looking at these two items from the top was a brilliant idea of a German Forum member @TS25 who seems to have lost his interest a long time ago but he was the person to give the best advice to me!)

 

[freewheeling]

Hmm... When you place the chain on the chainring, just look at the chainring and chain from the top. It soon becomes obvious what the correct pattern is. The diagram on the inner side of the chainring makes the operation a no-brainer but the experience comes fast. (Looking at these two items from the top was a brilliant idea of a German Forum member @TS25 who seems to have lost his interest a long time ago but he was the person to give the best advice to me!)

Stefan, so we agree that the correct placing of the chain on either the Praxis or a standard narrow-wide chainring is really important. Would you also agree that these types of chainrings were only brought into the mainstream when 1X (single-ring chainring) drivetrains started to become a thing? Would you agree that SRAM was the first mainstream manufacturer of 1x drive trains in 2012? They became popular among enthusiasts a few years later but they only became commonplace when the technology trickled down to more entry-level components (i.e cheaper).

The market for the Specialised Vado SL includes both enthusiasts and non-enthusiasts who last bought a bike without this technology and without the associated knowledge, albeit simple once you know. I have a bike with a Shimano 1x drivetrain with a non-Shimano narrow-wide chainring. But I had no experience with the type 3 clutch that SRAM now uses on its rear derailleurs or the wave pattern that Praxis employs on its chainrings. Both operate differently, which makes user diagnostics more challenging. Luckily for me, the Specialized dealer found that there was a problem with my Praxis Chainring and Specialized replaced it under warranty.

Perhaps we need to be more gracious and help folk diagnose the problem without minimising their bike experience.

 

[Stefan Mikes]

Stefan, so we agree that the correct placing of the chain on either the Praxis or a standard narrow-wide chainring is really important. Would you also agree that these types of chainrings were only brought into the mainstream when 1X (single-ring chainring) drivetrains started to become a thing? Would you agree that SRAM was the first mainstream manufacturer of 1x drive trains in 2012? They became popular among enthusiasts a few years later but they only became commonplace when the technology trickled down to more entry-level components (i.e cheaper).

I either agree with you or assume you know it better!

The market for the Specialised Vado SL includes both enthusiasts and non-enthusiasts who last bought a bike without this technology and without the associated knowledge, albeit simple once you know. I have a bike with a Shimano 1x drivetrain with a non-Shimano narrow-wide chainring. But I had no experience with the type 3 clutch that SRAM now uses on its rear derailleurs or the wave pattern that Praxis employs on its chainrings. Both operate differently, which makes user diagnostics more challenging. Luckily for me, the Specialized dealer found that there was a problem with my Praxis Chainring and Specialized replaced it under warranty.

Indeed, the SRAM derailleur clutch works differently from the Shimano one. This Forum let me understand the difference.

The chain placement on the modern chainring is important. If one used a Search function of this Forum, there is a huge illustrative thread explaining everything about chains and chainrings (I'm too lazy to locate it myself!)

As I understand, your original chainring was bent. Bad luck! Good the cause got identified!

 

[GuruUno]

While I ALWAY back mine and my wife's Vado and Como into the garage after a ride, I've never had a chain drop doing so.
However, there have been times (not too many) when I heard some odd noise doing so.
I attribute it to what gear it's in while backing it up. The lowest (gear 1) makes no noise while pushing backwards.
However, if not mistaken, higher gears do make noise.
I'll recreate today and validate..

 

[Stefan Mikes]

I attribute it to what gear it's in while backing it up.

You mean, rotating the cranks backwards? No. The cranks spin freely backwards, no connection to the chainring. Check it with your hand (but hold the chainring with the other hand).

 

[GuruUno]

I mean I 'push' the bikes backwards, holding the handlebars at the front of the bike, and putting it to the spot where it gets parked. Like I said, 'sometimes' it makes a weird noise, and it might be what gear it is in when pushing back, as there have been time when pushing, the pedals/crank move.

 

[Stefan Mikes]

I mean I 'push' the bikes backwards, holding the handlebars at the front of the bike, and putting it to the spot where it gets parked. Like I said, 'sometimes' it makes a weird noise, and it might be what gear it is in when pushing back, as there have been time when pushing, the pedals/crank move.

Oh, OK.
No freewheel (motor or the rear hub) works when the e-bike is being backed.

 

[lilchris]

Thanks guys for your advice, the only thing that worries me now is my chain has come off twice in the same scenario, ie moving the bike backwards. I really struggled the first time it happened which was at home in my back yard, I had not noticed the chain had come off till I was outside my gate. I eventually freed it and got it back on the sprocket, have I got it back on the right sprockets well that is a good question. It did come off again but a few weeks later, again backing the bike up, this time I noticed straightaway so I laid the bike on its side and replaced the chain, again is it in the right position ? I just wanted the chain back on so I could get home, it seems to have been ok ever since. I now take care if I back the bike up, I now deliberately leave it in third gear, that way the chain is not has crossed up. I will also get the rear derailleur checked I am wondering if that is slightly out of line and could that possibly cause it to happen, anyway thanks again guys. By the way I might take my chain guard off like the picture of Stefans bike above, at the moment I am wearing shorts but I still have cycle clips bought in the 1960's...lol, it would be easier to get the chain back on.
Chris.

 

[carlodim]

Thought I'd tell you about my experience with random and then permanent dropped chain and it jamming between the chainring and bike when shifting into the largest cog in the rear cluster of my Turbo Vado SL 4.0 EQ.
My Specialized dealer finally fixed the problem by changing the chainring under warranty - the bike is still less than a year old. I now have a Wolf Tooth Drop Stop and it seems to have finally fixed the problem. Gear changing has never been smoother too.

 

[mjh5]

Yes, the derailleur cage can easily be moved by hand at any time. It has a button to hold the derailleur out of the way to aid wheel removal. But there's no on/off button or a way to adjust the tension on the derailleur, which when compared to my experience of Shimano's XT the SRAM Horizon NX has very weak tension. i.e. the SRAM Horizon NX clutch doesn't resist chain slap enough to work with the Praxis front chainring and in light offroad/pathway riding the bike is susceptible to the chain coming off the front chain ring. This would be a mild inconvenience if it wasn't for the fact that the chain gets stuck between the frame and the chainring. In the old days of front derailleurs, you would adjust the limit screws so the chain could not get trapped in this way. It's up to Specialized to specify the appropriate drive chain components for the intended use of a bike. Specialized, like many mass-market manufacturers, chose to mix and match drivetrain components from different suppliers. Specialized take a risk when it does as there is a risk that tolerances need to be higher than that designed into the individual components. Other bike manufacturers stick to a complete drivetrain from a single supplier (historically SRAM, Shimano, Campagnolo but there are others.).

I suspect that it's a relatively rare occasion when it happens, maybe after somebody has had the bike for a while and it's put down to poor maintenance or owner ignorance.

I had this happen twice during the break-in period. Both times when either going into the lowest (easiest) gear or going from the lowest to the next gear. My dealer did an adjustment and changed the chain as well at no cost to me. It hasn't happened since but I am careful not to go into the lowest gear unless I'm within a couple of miles of my home. And you are correct that it would just be an inconvenience except that the chain gets really stuck between the frame and the chainring, and it took about 20 minutes each time to get it out. Not even shure how I got it out. And there is no chain guard. Apparently the Creo Sl had enough of this problem that they made a chain guard that works on the Creo Sl but not on the Vado Sl. This is what Specialized Rider Care said when I asked if the one for the Creo SL worked on the Vado SL: "The Turbo team has confirmed this chain guide unfortunately will not fit on the Vado SL. The bolt hole this attaches to is too deep." On the Creo the bolt hole is on the motor housing. One would think it would be possible to find a longer bolt to get this to work on the Vado Sl.