# Problem: Chain skip under load



## Xirj (Sep 5, 2008)

Hi there, it's my first time posting here so hopefully I don't sound like a total douche.

I got a 2008 Kona Fire Mountain last week and have been quite happy with it except one problem. Under load, for example starting up a slope and in middle or small gear, it sounds and feel like my chain will skip a couple links sometimes. It's usually when I'm putting down the most power too. It doesn't happen when I'm going fast in a straight line, only at high torque.

When I went in today for adjustments and to fix cable stretch, the dude said that it can because of my bottom bracket (the thing that my cranks connect to). He said that they put cheap ones in the FM and that they can wobble and that's why my chain might skip.

I was wondering if this makes sense as the cause of my problems? It still happened even after tightening up the lines to the derailleurs and realigning them (my front was rubbing against the chain).

Thanks in advance


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## Call_me_Al (May 31, 2008)

That could be possible, but another thing I would suggest is to make sure you are not cross-chaining, i.e. smallest chainring/ smallest cog, biggest chainring/biggest cog.

Also, try fiddling with the barrel adjuster for the rear derailleur (should be where the cable meets the shifter) to adjust derailleur alignment when you are between the high and low extremes, if this hasn't already been done. The screws on the derailleur only adjust the high and low endpoints.


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## MOJO K (Jan 26, 2007)

What Al said plus...check for play in the rear wheel (bearing adjustment) and make sure the quick release is snug. If it continues, don't let it go. New drivetrain parts, even lower end, shouldn't do this. It's on the shop to make it right.


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## borregokid (Feb 18, 2004)

So is it skipping off the chainring or cassette? The first place to look is the chain. I would take it off the bike and clean it and look for any stiff links. It wouldnt be unusual to find a stiff link on a new bike. If its skipping on the same gears on the cassette you might have slightly bent a gear. When it starts skipping under load try adjusting your shifter with the barrel adjustment. Sometimes that solves the problem. 

If minor adjustments with the barrel dont work and the chain has been cleaned and lubed you are looking at chasing stuff down by throwing money at it. The shop should be able to trace the problem down. They probably can throw on some slightly used but functional stuff to see where the problem is. Typically most people will get a new chain and then cassette or maybe both at the same time to solve chain skip. 

I am not sure about the crankset wobble theory but I dont like the cheaper LX and lower grade rings and have had problems with skipping on the chainrings. The teeth tend to break and wear quicker. The crankset solution is quite a bit more expensive. A used XT 760 off of Ebay is probably in the $120 range.


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## WrenchDevil6 (Apr 3, 2008)

Not to discount the obvious, but this has happened to me:

Have you checked to see that you still have all the teeth on that particular gear? I have sheared teeth off under load and rendered that particular gear useless. Mind you that this was on lower end cassettes and mostly in winter, but all the same take a look and see that all the teeth are there.


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## Xirj (Sep 5, 2008)

Thanks for all the replies. I am not sure I will be able to catch it with the barrel adjustment as the "crunch" sound of the skip is quite quick. It feels like the cassette. 

I'll rethink my strategies of shifting and gearing though, cross-chaining has never come to mind. If it does persist, then i'll try to find the exact conditions that it happens in so I can better explain myself to the bike store. I wouldn't be happy to HAVE to upgrade from stock to get expected performance from the brand new bike.


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## marsh rider (May 18, 2008)

Most of the chain skipping in my experience has come from a tight chain link, mostly because I would take the chain off and then put it back together too tight. To check this easily, put the chain in the largest rear gear and middle front gear and flip the bike over. Then just slowly turn the pedals in reverse (so the wheel doesn't turn) while watching the rear derailleur cage. If the bottom pulley gear pulls forward at any point, you've got a tight link.


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## WrenchDevil6 (Apr 3, 2008)

Xirj said:


> If it does persist, then i'll try to find the exact conditions that it happens in so I can better explain myself to the bike store. I wouldn't be happy to HAVE to upgrade from stock to get expected performance from the brand new bike.


Better yet, take it to the shop and let their guy ride it and see if he can recreate it.


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## PhillyO (Dec 6, 2007)

So the guy at the lbs told you it was a faulty crank, well thin it seems to me the need to change the crank for you for free under warranty if the bike is new and only a week old. sounds to me like he doesnt know what his talking about or his tring to blow you off. its a new bike they need to fix it bottom line. but it could be a number of things stiff link, dirty chain, derralier out of adjustment. mine did the same after a switched from 8 speed to 9 speed(derailler was out of adjustment).


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## savagemann (Jan 14, 2008)

My money is on a stiff link...........Bring the bike to the shop you bought it at, and have them remedy the problem. Also, ask them to retorque the crank bolts after they figure it out as well.


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## cyrix (Jan 29, 2008)

Uh....while I do think that maybe fine tuning your rear derailleur might help, don't go all gung ho into it.

Here is a nice little tut video on youtube about making adjustments.






They also have other good videos on bike maintenance.


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## Xirj (Sep 5, 2008)

Is there a way I can tell if there is a stiff link without taking the chain off myself? I just don't have any tools myself. I'll ask the LBS next time but was wondering if I could diagnose before going riding tomorrow.

Marsh rider's technique would tell me if my chain is too short/tight but wouldn't diagnose a stiff link right?


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## aaron04 (May 26, 2008)

Have you looked at the rear cassette while its in each gear, maybe the rear derailleur is tilted to far back not letting the chain wrap around one or more of the rear rings enough, if the chains not wrapped around enough it could let the chain climb the teeth and skip. I have had this happen on one of my road bikes, the rear derailleur was tilted too far back and the chain was only touching about 1/3rd of the sprocket. You need the chain to be wrapped around half of the ring or so otherwise the chain will climb the teeth and that hurts!


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## cyrix (Jan 29, 2008)

Xirj said:


> Is there a way I can tell if there is a stiff link without taking the chain off myself? I just don't have any tools myself. I'll ask the LBS next time but was wondering if I could diagnose before going riding tomorrow.
> 
> Marsh rider's technique would tell me if my chain is too short/tight but wouldn't diagnose a stiff link right?


Put the bike upside down on the bars and seat and move the rear derailleur forwards towards the front cog and check the links with the other free hand.

Yes it's kind of "ghetto" but it can and does work when you're in a pinch.


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## -Devil- (Feb 28, 2008)

my 'chain skip' ended up just being how i pedaled ... when i would go from coasting to sudden pedal i would hear it ... or when i was pedaling hard, but would stop for a second to maneuver around something and start again it would do it ... it was more the slack in the chain being taken back up then it actually skipping ...


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