# Intermittent Chain "popping"



## skankingbiker (Jan 15, 2010)

The last few weeks I have been experiencing intermittent chain popping when under heavy load (i.e. big climbs). Only happens once or twice on a ride. I keep my chain clean and lubed. I checked for stiff links and found none. Chainline is spot on. Tension is good. 

Time for a new chain?


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## drMP (Jun 4, 2006)

I too get it... Not sure why but I"m not using any master links (hard pinned). I am guessing it's from frame flex and the sides getting caught on tooth?


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## Crosstown Stew (Aug 16, 2008)

Do either of you guys use a chain tensioner? I had this problem when I ran a surly tensioner. Mine was a combination of a link being mashed from cutting the chain, and too much chain. I took off the link that was mashed and put in a half link and that fixed it.


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## drMP (Jun 4, 2006)

Nope, SS specific ride (Spot). But i'll look for a buggered up chainlink.


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## rensho (Mar 8, 2004)

Can you guys define 'chain popping'? What exactly happens?

What hubs or freewheels are you running?


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## drMP (Jun 4, 2006)

Hope SS hub, king bottom bracket and HBC rings


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## sunset1123 (Apr 28, 2009)

drMP said:


> I too get it... Not sure why but I"m not using any master links (hard pinned). I am guessing it's from frame flex and the sides getting caught on tooth?


That would be a TON of flex. I've experienced this, and the chain usually derails and sometimes takes the tip of a tooth or two with it. My frame ended up being cracked around the bottom bracket.

What can happen though, is that frame flex causes chain tension to vary. You will notice the "popping" only tends to happen at the end the DS pedal stroke? That's where flex will change chain tension, leading to some slop, that will quickly be taken up, reulting in the "pop"... a REALLY smooth pedal stroke eliminates this, and I have NEVER had it happen on a fixed gear.

I used to sometimes encounter this also at the bottom of a DS pedal stroke when doing something like a wheelie drop or pedal kick to lift the front. Strong pedal kick, and then a "pop" as the tension goes back in the chain as the NDS pedal comes around.

Hope that helps. If its something different, I have no idea. I do know you don't really have to worry about this phenomenon described above as long as it is infrequent. If it starts happening all the time, look at chainline and have your frame checked for cracks.


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## cbrossman (Mar 23, 2004)

I get the same thing occasionally, and I keep everything clean and tidy.
It seems to happen when I coast for a bit, usually because I need to catch my breath, and then on the next crank forward. Once or twice during a 2 hour ride.


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## CHUM (Aug 30, 2004)

i got a couple little 'pops' on yesterdays ride (a choppy 3 hours)....

I9 hub, HBC rear cog (1/8"), and Middleburn front ring (1/8")....tension is good and alignment is spot on.

i am, however, running a total POS PC-1 chain that I'm sure is fubar'd at this point.

i'm gonna throw on a PC-7X to see if it happens again.


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## skankingbiker (Jan 15, 2010)

I run Shimano XT hubs. The "popping" sound occurs at the bottom of the DS pedal stroke. it feels like the drivetrain is binding (kind of like when my chain tension on my fixie is too tight) and then "snaps" back into place. I have my tension set so that there is enough play even in the "tight" spot of the pedal rotation, so I do not think this is the issue. Don't recall seeing any frame cracks. Hope it is not my hub.


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## slocaus (Jul 21, 2005)

I knew I saw this recently.
http://forums.mtbr.com/showthread.php?t=646286&highlight=chain+popping


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## miatagal96 (Jul 5, 2005)

I get 'popping' under load when my chain is a little loose.

My husband had this problem and found that the spider on his crank arm wasn't perfectly centered (he could measure the variation in spider bolt to crankset center between the bolt holes), so the chain would loosen then tighten every pedal stroke. He swapped cranksets and the second one wasn't as bad. Now he's on a mission to find the perfect SS crankset at a price he's willing to pay. Anyone got a Paul crankset for $100 ?


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## slocaus (Jul 21, 2005)

miatagal96 said:


> I get 'popping' under load when my chain is a little loose.
> 
> My husband had this problem and found that the spider on his crank arm wasn't perfectly centered (he could measure the variation in spider bolt to crankset center between the bolt holes), so the chain would loosen then tighten every pedal stroke. He swapped cranksets and the second one wasn't as bad. Now he's on a mission to find the perfect SS crankset at a price he's willing to pay. Anyone got a Paul crankset for $100 ?


It probably does not exist. 

Manufacturing tolerances will vary with crank arm to BB, spider circle, chainrings, not to mention the rear hub, cassette or FW threading, and the cogs or FW itself. You would need custom made components to exceedingly high tolerances to achieve that, the mass manufacturing market of interchangeable parts is not going to accomplish that.

Good luck on the under $100 part. Have him go find the Holy Grail, he will have better odds.


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## dtownmtb (Jan 20, 2004)

CHUM said:


> i got a couple little 'pops' on yesterdays ride (a choppy 3 hours)....
> 
> I9 hub, HBC rear cog (1/8"), and Middleburn front ring (1/8")....tension is good and alignment is spot on.
> 
> ...


Here's a possibility

Pull your hub apart and check the pawl springs. I chased down a sound like that for a long time. It sounded exactly like a drivetrain issue - chain specifically. Turned out a couple of pawl springs lost their spring. They were pushing a couple of the pawls only part way up. The pawls would partially engage until I cranked - then they would "pop" into place. You can sorta bend back the springs to give them their spring back - or get replacements from I-9.

The core problem turned out to be an issue with the hub - which I9 took care of. Their customer service is fantastic. They worked with me through the long process of figuring this out and made everything right.


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## CHUM (Aug 30, 2004)

dtownmtb said:


> Here's a possibility
> 
> Pull your hub apart and check the pawl springs. I chased down a sound like that for a long time. It sounded exactly like a drivetrain issue - chain specifically. Turned out a couple of pawl springs lost their spring. They were pushing a couple of the pawls only part way up. The pawls would partially engage until I cranked - then they would "pop" into place. You can sorta bend back the springs to give them their spring back - or get replacements from I-9.
> 
> The core problem turned out to be an issue with the hub - which I9 took care of. Their customer service is fantastic. They worked with me through the long process of figuring this out and made everything right.


will check :thumbsup:


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## rensho (Mar 8, 2004)

CHUM said:


> will check :thumbsup:


While you're in there, I'd pull 3 of the 6 paws out with springs, and leave them out. It will change the sound, reduce drag(while coasting, which I warned you not to do  ), and also get rid of this problem.

The problem will also change/go away by itself as the paws and ring wear, but that will require riding.


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## CHUM (Aug 30, 2004)

rensho said:


> While you're in there, I'd pull 3 of the 6 paws out with springs, and leave them out...


teamdicky did that...and was chastised by his mechanic.


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## UBUgoat (Sep 12, 2009)

i've noticed mine does that once in a while, but seemingly only on the road (or maybe that helps me notice it)....does seem to be the downstroke....ride, pedal, coast, then that little <twank> slip <ching> sound.....then it's back to normal.


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## ianschmitt (Jul 28, 2008)

Pretty much any single speed will eventually make this noise. Check your chain tension and chain line. Even with perfect alignment the amount of extra torque you're putting into the drivetrain can cause the ring/chain/cog to not line up perfectly and "pop". I've never experienced an issue with the popping outside of the actual noise.


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## UBUgoat (Sep 12, 2009)

until i saw this post, i was concerned it was in the cranks/bottom bracket....pretty new bike, but still not sure.


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## SeaBass_ (Apr 7, 2006)

Experienced this on my last ride and discovered my EBB had slipped from 9 o'clock to 8 o'clock and made my chain too tight so i was getting some binding under load.


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## e46junkie (Jan 25, 2011)

I had this problem a while back and discovered my chainring was loose... something else to check. Good luck!


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## drMP (Jun 4, 2006)

I noticed last night that one chainring bolt is missing! MAYBE that's my problem!! Probably have ridded 1000+ miles like that too?!


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## e46junkie (Jan 25, 2011)

Cool... bet thats it!


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## slocaus (Jul 21, 2005)

drMP said:


> I noticed last night that one chainring bolt is missing! MAYBE that's my problem!! Probably have ridded 1000+ miles like that too?!


Not only will that do it, but you are probably lucky, people who do not check their bikes carefully find the bolt missing when the chain ring folds / collapses with serious consequences!


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## bmateo (Jan 13, 2004)

Thanks for posting this thread. I get this once in a while too. I often wonder about it, but finally got off my azz to come here and research it. Violet, here it is.....


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## skankingbiker (Jan 15, 2010)

As an update, existing chain was stretched.. Replaced chain and at same time, put on new cog in the back. No popping noises the last 4 rides.


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## Cormac (Aug 6, 2011)

Finally got my conversion kit and converted my 1x8 to SS. So I was already running a SS specific chain ring. Blackspire mono veloce or whatever it's called. Used the same chain as I never had a problem with it before. Just cut it down to fit. Then on the maiden voyage of my new SS rig I noticed a pop about once per steep climb. At first I thought maybe the chain was stretched but when I got home looked the bike over and found the tensioner had came loose a little. Tightened that up and hopefully that'll fix the problem? Or should I put a new chain on and be done with it? Also I noticed a growling sound coming from somewhere that I can't pinpoint. But everything turns just fine. Could it just be the chain rolling on the tensioner roller? This is the tensioner I'm using for reference:
Sette Chain Tensioner at Price Point


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