Dropping chain

[PaulieV]

I'm running 1 x 11 on a 2017 Spez Stumpie. Sent bike to LBS reporting that I keep dropping the chain (off the front blade) but only when changing out of climbing gear. Bike shop said group set all good except front blade. Replace with a relatively new second hand one. Problem persists. 

What to do? Replace entire groupset with new? Derailer, chain and cassette all look fine.

 

[DieselnDust]

What chainring are you using?

[MTBRIDER1234]

11 minutes ago, PaulieV said:

I'm running 1 x 11 on a 2017 Spez Stumpie. Sent bike to LBS reporting that I keep dropping the chain (off the front blade) but only when changing out of climbing gear. Bike shop said group set all good except front blade. Replace with a relatively new second hand one. Problem persists. 

What to do? Replace entire groupset with new? Derailer, chain and cassette all look fine.

 

Here are a few questions that could help you get to the bottom of your problem:

 

Is it a narrow wide chainring? What is the chain wear? Are the limits and B-screw set properly? Is the chain too long/short? Have you put a new chain on a used cassette?

[PaulieV]

2 minutes ago, DieselnDust said:

What chainring are you using?

Not sure TBH as LBS popped an excellent condition 2nd hand one on just to elimate that as the problem. Chain hasn't stretched, limits and n-screw seem fine. And it's not a new chain.

I find it strange that it only ever drops when shifting out of climbing gear.

 

[MTBRIDER1234]

6 minutes ago, PaulieV said:

Not sure TBH as LBS popped an excellent condition 2nd hand one on just to elimate that as the problem. Chain hasn't stretched, limits and n-screw seem fine. And it's not a new chain.

I find it strange that it only ever drops when shifting out of climbing gear.

 

That is strange for sure. Is it a narrow wide chainring though? Also if a chainlink is bent then that could be what is causing that, but it is very unlikely. Maybe you could send a photo to help me get a better idea of it.

Also what wear is the chain at? And you are sure your chainring is not bent right?

Edited August 9, 2022 by MTBRIDER1234

[DieselnDust]

a photo of the set up would be most helpful.

Climbing gear? I assume you mean the biggest sprocket at the back?

[PaulieV]

17 minutes ago, DieselnDust said:

a photo of the set up would be most helpful.

Climbing gear? I assume you mean the biggest sprocket at the back?

Yes biggest sprocket. Will send pics tomorrow.

[MTBRIDER1234]

Just now, PaulieV said:

Yes biggest sprocket. Will send pics tomorrow.

Ok cool. Sorry to keep asking, but what is your chain wear at? This could play a huge role in your problem.

[PaulieV]

51 minutes ago, MTBRIDER1234 said:

That is strange for sure. Is it a narrow wide chainring though? Also if a chainlink is bent then that could be what is causing that, but it is very unlikely. Maybe you could send a photo to help me get a better idea of it.

Also what wear is the chain at? And you are sure your chainring is not bent right?

Will send pics tomorrow. Chain seems fine. LBS checked that. But if chain was a problem, would I only drop it on the largest sprocket?

[MTBRIDER1234]

2 minutes ago, PaulieV said:

Will send pics tomorrow. Chain seems fine. LBS checked that. But if chain was a problem, would I only drop it on the largest sprocket?

It really depends, I have seen a worn chain cause problems in some gears and not others. Rather check it and eliminate another factor then leave it - while it may be the problem. If you don't already have a chain checker, I highly recommend you get one, they are cheap and very useful. 

[DieselnDust]

i also assume you're dropping this chain from the largest sprocket while pedalling forward....?

and not while pedalling backward

[MTBRIDER1234]

5 minutes ago, DieselnDust said:

i also assume you're dropping this chain from the largest sprocket while pedalling forward....?

and not while pedalling backward

Had a lot of people tell me their gears are broken when they backpedal in the largest cog on a 1x system... it is just a quirk that most of them have

Also if it works nicely when pedalling forwards, then why worry about it when pedalling backwards haha

[robbybzgo]

After my 1 X 11 xt gear set was no longer new it started dropping off the main ring while in the smallest rear cog (at speed and a bumpy trail). Put on a good quality carbon chain guide and never dropped the chain again. This might help you??

[RobertWhitehead]

2 hours ago, PaulieV said:

I'm running 1 x 11 on a 2017 Spez Stumpie. Sent bike to LBS reporting that I keep dropping the chain (off the front blade) but only when changing out of climbing gear. Bike shop said group set all good except front blade. Replace with a relatively new second hand one. Problem persists. 

What to do? Replace entire groupset with new? Derailer, chain and cassette all look fine.

 

I am 99% sure I know the answer to your dilemma but, it is dependent on the size of the chain ring you're running. If it is a 34 or smaller then ignore me. If it is a 36 or bigger then tin tin tin...... 

[babse]

1 hour ago, RobertWhitehead said:

I am 99% sure I know the answer to your dilemma but, it is dependent on the size of the chain ring you're running. If it is a 34 or smaller then ignore me. If it is a 36 or bigger then tin tin tin...... 

36 or bigger on a 1x11... Doubt it 

[ChrisF]

8 hours ago, RobertWhitehead said:

I am 99% sure I know the answer to your dilemma but, it is dependent on the size of the chain ring you're running. If it is a 34 or smaller then ignore me. If it is a 36 or bigger then tin tin tin...... 

 

Why ?

 

I have two bikes with 1x11 and 36 rings.  No drops in 8 000 km.

 

One has a chain guide.  No guide on the other