Question on 'dropped chain'?

GuruUno

Well-Known Member
On my 2022 Vado 5.0, it happened again. (3rd time in 2500 miles/4 months+)
I upshift and downshift quite frequently, depending on terrain, speed, and cadence.
Much like almost having a seamless CVT transmission, but in reality an 11-speed setup as OEM.
I changed the cassette at about 1800-2000 miles, and the chain also.
I have used an ultrasonic cleaner and hot wax exclusively and never really have any problems.
However, today was the 3rd time in the last few months (both 'old' and 'new' cassette/chain) that while downshifting the chain just comes off the chainring and gets jammed up behind it. I lock down the derailleur and put it back and I'm good to go.
Is this expected behavior or am I doing something wrong or is there an adjustment needed?
I really have no problems with the shifting otherwise.
 

GuruUno

Well-Known Member
Do you already have a narrow-wide chainring?

It's not obvious in the picture.
Turbo Vado 5.0 | Black / Black / Liquid Silver
That picture is a 2021, not 2022.
Yes, it is narrow/wide
 

EMGX

Well-Known Member
Might not be your issue at all but I had chain drop when the chainring bolts got loose. It took a while for me to figure it out.
 

LLL

New Member
Region
USA
Not sure if this helps, but I put this on my wife's ebike to stop the chain from jumping off every once in a while or when she was powering over bumps on the trails (or bike lanes). Seems to have taken care of the problem for her.

CYSKY Chain Guide Mountain Bike, MTB Chain Guide Direct Mount Chainring Guard Perfect for Most Bicycle Road Bike Mountain Bike BMX Fixie (Alloy Aluminum, Black) https://a.co/d/1S3BrCW
 

GuruUno

Well-Known Member
I read this on the Trek forum and was curious as to if anyone had referenced the info there too.
and
 

Bobber

Member
Region
USA
City
Charleston, Westfuckingvirginia
I had this really bad, like every ride bad, sometimes multiple times in a ride bad. Turns out my chain was stretched which makes it not fit the sprockets perfectly. I have a new chain now and all is groovy again. Do you have a chain gauge to check yours? You can also just do a visual and can see if the chain and sprocket alignment is exact. Check how it fits around the front sprocket. I have a 1000 watt mid drive so I have resigned myself to replacing the chain about twice a year. You say your last chain swap was about 500 to 700 miles ago so you might be due specially if you and your motor really torque it up.
 

LLL

New Member
Region
USA
I had this really bad, like every ride bad, sometimes multiple times in a ride bad. Turns out my chain was stretched which makes it not fit the sprockets perfectly. I have a new chain now and all is groovy again. Do you have a chain gauge to check yours? You can also just do a visual and can see if the chain and sprocket alignment is exact. Check how it fits around the front sprocket. I have a 1000 watt mid drive so I have resigned myself to replacing the chain about twice a year. You say your last chain swap was about 500 to 700 miles ago so you might be due specially if you and your motor really torque it up.
Wow, I must be very lucky with my m620 and bbs02 motors. Currently over 2k miles on both, and my chains and cassettes still measures almost new (not stretched). I am very diligent on keeping things clean and lubed, and easy on my shifts (wait until the motor is disengaged).

Either way, I hope a simple chain guide will help the original poster vs a chain.
 

kahn

Well-Known Member
Region
USA
City
northWET washington
I had the occasional chain drop on my Creo. But when it dropped it would fall between the crank and motor housing, so it was really jammed in there. It took quite a bit of careful work to extricate it without damaging the chain (nevermind the motor housing/etc).

But one day it was really, really bad. It must have come off more than a dozen times. Finally, called a friend to end the suffering and get a ride home. Turns out that my derailleur hanger was bent.

But another thing to check is that the clutch is in the correct position.
 

Bobber

Member
Region
USA
City
Charleston, Westfuckingvirginia
I think I was rougher on the mechanics than I should have been. On the other hand there are loads of really steep hills around here so the parts are always getting a workout, I should lube more too. I got an education on this thread:
I just installed that $17 chain from Amazon. Fingers crossed.
 

GuruUno

Well-Known Member
Turns out that my derailleur hanger was bent.

But another thing to check is that the clutch is in the correct position.
"it would fall between the crank and motor housing"
Exactly my same issue

Not bent, positive. (derailleur)

Additionally, either I'm blind or? I don't see a 'clutch lever', as I had on my previous Vado. (2021 previous, 2022 now)

Does a SRAM GX rear derailleur have a clutch?​

If so, please show me where it is?

Thanks


 

mschwett

Well-Known Member
Region
USA
"it would fall between the crank and motor housing"
Exactly my same issue

Not bent, positive. (derailleur)

Additionally, either I'm blind or? I don't see a 'clutch lever', as I had on my previous Vado. (2021 previous, 2022 now)

Does a SRAM GX rear derailleur have a clutch?​

If so, please show me where it is?

Thanks


there are a couple different GX RD. is it this one?

614BFDD3-AF69-488A-9E7B-36EC9C34F9AB.jpeg
 

PedalUma

Well-Known Member
Region
USA
City
Petaluma, CA
Okay, Firstly clean the derailleur very well. Lube it with Lucas Full-Auto Gun Oil. This is high pressure, slick and does not attract grime. Get each moving part with a drop or two of oil and articulate it. Wipe off excess. Then see a Park Tool vid on chain length. It may have an extra link. Taking that out will tighten things up. Then see a video on derailleur adjustments including the hanger with a DHAG-II. If it overshoots first gear then the low screw is too slack. Just some thoughts. I hope this is helpful.
 

Avg_Joe

Well-Known Member
Region
USA
City
RDU, NC
Had this happen on my Vado for the first time last night, as @kahn experienced my chain was really jammed in between the crank and motor housing. Broke the plastic chain guard, scratched up the frame, but I was able to pedal home.

I was not shifting when it happened. I had just gone through a very short, rocky (not gravel) area at speed. I'll clean it all up this afternoon and have a long look, check chain stretch, but am kinda leaning towards I went through a rough patch way too fast and the chain bounced off? Anyway, thanks for starting this thread @GuruUno and I appreciate those who chimed in with what all to look at.
 

PedalUma

Well-Known Member
Region
USA
City
Petaluma, CA
Had this happen on my Vado for the first time last night
See if you can get away with one less link. Were you in a high gear? That is when the derailleur is most slack, or not providing much tension. The way to check if the length is correct is to make a chain hook from a spare spoke. It is just a 75ish mm length with a hook at each end that pulls a chain together.
 

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Avg_Joe

Well-Known Member
Region
USA
City
RDU, NC
See if you can get away with one less link. Were you in a high gear? That is when the derailleur is most slack, or not providing much tension. The way to check if the length is correct is to make a chain hook from a spare spoke. It is just a 75ish mm length with a hook at each end that pulls a chain together.
I was in 4th gear. I appreciate the suggestion, @PedalUma but am a bit confused: if I make a hook, what then am I looking for? slack? Sorry for being dumb n00b.
 

PedalUma

Well-Known Member
Region
USA
City
Petaluma, CA
I was in 4th gear. I appreciate the suggestion, @PedalUma but am a bit confused: if I make a hook, what then am I looking for? slack? Sorry for being dumb n00b.
It is all good. See a Park Tool video that shows rear derailleur setup as it relates to chain length. The hook will show if you can take out a link while not having it too tight in first gear. It took me awhile to get up on the curve by making mistakes. I am attaching a photo of a bike I made electric today. 85Nm, torque sensor. It was a non-electric Giant Momentum Vida Mid-step. I changed a bunch of things about it plus, adding the mid-drive.
1667419194391.jpeg
 

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Avg_Joe

Well-Known Member
Region
USA
City
RDU, NC
It is all good. See a Park Tool video that shows rear derailleur setup as it relates to chain length. The hook will show if you can take out a link while not having it too tight in first gear. It took me awhile to get up on the curve by making mistakes. I am attaching a photo of a bike I made electric today. 85Nm, torque sensor. It was a non-electric Giant Momentum Vida Mid-step. I changed a bunch of things about it plus, adding the mid-drive.
View attachment 139248
Right on, thanks so much! I'll check out Park videos and see what comes of it.
 

GuruUno

Well-Known Member
As initally indicated, it has only happened a few times, and mostly when aggressively downshifting and slowing. No issues, done nothing, but will keep you all informed as I progress.
 

Allan47.7339

Well-Known Member
The SRAM GX 1x11 X-HORIZON Rear Derailleur features a built in clutch and a Cage Lock to make it easier to remove the wheel. I suspect the Praxis chainrings wear faster than normal on an e-bike. After about 3700 miles (6000km), I started to get random drops with old chain, new chain, clutch off and clutch on. I switched to a Wolftooth chainring because I wanted a 42T and I have not had a dropped chain in the last 500 miles. It may be random chance but it seems to be fixed with a new chainring and I won't worry about it until it starts up again.