# Chain jump on high gear cog



## Danielrg_usa (Feb 12, 2011)

Okay, some of you may know already form my other threads that I got new wheels for my bike. Shimano XT/Rhyno Lites from Jenson with Maxxis High Roller tires and the Stans kit. Anywho, I got them all mounted and sealed, cleaned up my drive train, and recentered my calipers. Took the bike outside for a test ride and now all of a sudden my chain is jumping high gear on the rear cog. Only high gear though. It did not do it before my wheel swap. 

I did a quick search and read through a couple threads and here is what I have done so far. 
1. Took the wheel back off, removed the cog set, inspected it, and put it back on making sure it was on properly and tightly. 
2. Checked the adjustment of my derailleur. I loosened the cable from the derailleur(Sram SX-4) itself, reset the barrel adjuster on the shifter(Sram SX-4), and pulled the cable tight as I retightened it to the derailleur. Shifting is now much better than before. 
2. Tried to see if I could notice any flaws in the chain as it ran over the cog in low gear(largest cog)
3. Tightened up my derailleur hanger and tried to determine if it is bent along with the derailleur itself. 

I do not have a chain length measuring tool to check chain stretch. Is there a measurement that it should be that I can use to determine if it is streched using a caliper? I am running the stock drive train as a 1*8. I just took the small chainring off the front. What am I missing, doing wrong, need to do next?


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## Danielrg_usa (Feb 12, 2011)

Sent using my fat thumbs!


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## shiggy (Dec 19, 1998)

Danielrg_usa said:


> Okay, some of you may know already form my other threads that I got new wheels for my bike. Shimano XT/Rhyno Lites from Jenson with Maxxis High Roller tires and the Stans kit. Anywho, I got them all mounted and sealed, cleaned up my drive train, and recentered my calipers. Took the bike outside for a test ride and now all of a sudden my chain is jumping high gear on the rear cog. Only high gear though. It did not do it before my wheel swap.
> 
> I did a quick search and read through a couple threads and here is what I have done so far.
> 1. Took the wheel back off, removed the cog set, inspected it, and put it back on making sure it was on properly and tightly.
> ...


Need to adjust the high limit screw on the RD. Check the low limit screw, too, or you may have the chain shift into the spokes.

Fairly common when changing wheels.


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## kjlued (Jun 23, 2011)

Simple derailleur adjustment should fix the problem.

2 - Adjusting a Rear Derailleur - YouTube


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## Danielrg_usa (Feb 12, 2011)

shiggy said:


> Need to adjust the high limit screw on the RD. Check the low limit screw, too, or you may have the chain shift into the spokes.
> 
> Fairly common when changing wheels.


I did adjust my High and Low limit screws.



kjlued said:


> Simple derailleur adjustment should fix the problem.
> 
> 2 - Adjusting a Rear Derailleur - YouTube


Derailleur is shifting good in all gears. Maybe I should not have said the chain is jumping the cog. The chain is slipping on the cog under power. Did I miss communicate?


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## Millfox (Jun 22, 2012)

How is your chain/cassette worn? Perhaps its to time to switch?


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## Danielrg_usa (Feb 12, 2011)

Just found this in another thread posted by Billee. Now I can measure my chain and see if that is worn. I can not tell if the cogs are worn. I was hoping someone with more experience could take a look at the pics I posted and let me know. 

"new chain = 5.715 in.
1/2% stretch (equivalent to 1/16 in. over 12 in.) = 5.745 in.
3/4% stretch (equivalent to 3/32 in. over 12 in.) = 5.760 in.
1% stretch (equivalent to 1/8 in. over 12 in.) = 5.775 in."


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## Bill in Houston (Nov 26, 2011)

Danielrg_usa said:


> I can not tell if the cogs are worn. I was hoping someone with more experience could take a look at the pics I posted and let me know.


Well, I'm no expert, but that wee one does seem to be worn a bit shark-toothy, and has some burrs. I'd replace that one and the chain. Look and see if the chainring has worn funky too.


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## J.B. Weld (Aug 13, 2012)

If the chain is worn and the cassette hasn't been replaced recently then you should change them both. It is hard to tell a worn cog from a picture, or even first hand unless it's pretty bad, but that is a common cause of skipping or jumping under pedal pressure.

Strange that it didn't do it before you changed the wheels though, I'm with shiggy- from the picture it looks like the derailleur isn't lined up under the cog and high the limit screw may be a bit off.


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## Danielrg_usa (Feb 12, 2011)

I'll take the chain off and recheck the high limit screw. Maybe I'll be able to see it easier. The front chainring looks good to me. It has not given me any issues. Just the 11T gear and not till now.


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## deke505 (Jul 29, 2012)

J.B. Weld said:


> If the chain is worn and the cassette hasn't been replaced recently then you should change them both. It is hard to tell a worn cog from a picture, or even first hand unless it's pretty bad, but that is a common cause of skipping or jumping under pedal pressure.
> 
> Strange that it didn't do it before you changed the wheels though, I'm with shiggy- from the picture it looks like the derailleur isn't lined up under the cog and high the limit screw may be a bit off.


when ever changing cassettes it is a good idea to change both at the same time.

It could also be the wheel might have been trued a little out of alignment.


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## Danielrg_usa (Feb 12, 2011)

deke505 said:


> when ever changing cassettes it is a good idea to change both at the same time.
> 
> It could also be the wheel might have been trued a little out of alignment.


How does a wheel being out of true cause a chain to slip a cog? I am having trouble picturing how this would happen.


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## ThundaCrymz (Oct 22, 2012)

I only have a couple of questions regarding your drivetrain:

Did your old setup also have a 8 speed freewheel/cassette?
And did your previous freewheel/cassette have a 11t as the high gear?

Yeah usually if the chain is skipping on only one gear it's a worn cog, and if it's more than one gear it would/ could be the chain.


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## Danielrg_usa (Feb 12, 2011)

Cassette and chain remain the same. So, yes it has always been an 8 speed with an 11 tooth high gear. I have not measured my chain yet because my calipers are at my sister's house. I'll be getting them tonight. It sounds like I will most likely be replacing my cog set and chain though. I'll be sure to take another good look at my chainring too. I'll be changing the whole cassette but for reference is it possible to replace just the 11T cog by itself? I prices my new cog and chain. Should come in under $40.00. From what I have read chains and cogs are pretty expendable so I'm not going to throw a lot of money into them. Plus the cheap stock set has lasted many miles. 

Sent using my fat thumbs!


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## shibiwan (Sep 2, 2012)

Is it happening on all the front chainrings?


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## shibiwan (Sep 2, 2012)

Is it happening on both the front chainrings? .... or only when a certain chainring combo is selected?


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## Danielrg_usa (Feb 12, 2011)

It is a 1*8 and only in high gear. 11t cog

Sent using my fat thumbs!


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## shibiwan (Sep 2, 2012)

Danielrg_usa said:


> It is a 1*8 and only in high gear. 11t cog
> 
> Sent using my fat thumbs!


Could be a chainline issue. Slight differences between both hubs on the different wheels is probably causing the chain to be pushed outwards towards the stay more and end up getting caught in the next gear up just slightly enough to cause the skip when you apply force to the cranks.

Possible solution: shim out the crank/chainring a little more to the drive side (1-2mm makes a ton of difference). It should take up the little difference and both wheels should work nicely without needing to constantly adjust between wheels.

-S

Sent from my DROID4 using Tapatalk 2


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## deke505 (Jul 29, 2012)

Danielrg_usa said:


> How does a wheel being out of true cause a chain to slip a cog? I am having trouble picturing how this would happen.


if the wheel is dished in or out then the chain line isn't straight, the result could cause the chain to slip


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## Danielrg_usa (Feb 12, 2011)

deke505 said:


> if the wheel is dished in or out then the chain line isn't straight, the result could cause the chain to slip


Isn't that more of the hub not being centered on the axle or in the frame? Dishing is the centering of the rim itself in relation to the hub.

Sent using my fat thumbs!


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## deke505 (Jul 29, 2012)

Danielrg_usa said:


> Isn't that more of the hub not being centered on the axle or in the frame? Dishing is the centering of the rim itself in relation to the hub.
> 
> Sent using my fat thumbs!


Yes that. Sorry some times I get my wording or what I am trying say comes out wrong.:thumbsup:


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## ThundaCrymz (Oct 22, 2012)

Danielrg_usa said:


> Cassette and chain remain the same. So, yes it has always been an 8 speed with an 11 tooth high gear. I have not measured my chain yet because my calipers are at my sister's house. I'll be getting them tonight. It sounds like I will most likely be replacing my cog set and chain though. I'll be sure to take another good look at my chainring too. I'll be changing the whole cassette but for reference is it possible to replace just the 11T cog by itself? I prices my new cog and chain. Should come in under $40.00. From what I have read chains and cogs are pretty expendable so I'm not going to throw a lot of money into them. Plus the cheap stock set has lasted many miles.
> 
> Sent using my fat thumbs!


If you're able to find some single cogs for your cassette, then that would be a more cost effective solution for look for those instead of having to replace the whole cassette. Also, I remember having a similar issue with a skipping cog, but for me i needed a different rear derailleur to handle the higher torque from the smaller cog


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## Danielrg_usa (Feb 12, 2011)

deke505 said:


> Yes that. Sorry some times I get my wording or what I am trying say comes out wrong.:thumbsup:[/QUOTE
> 
> No harm no foul. When I pick up my calipers tonight I'll check my hub centering on the axle.
> 
> ...


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## Danielrg_usa (Feb 12, 2011)

Okay, my chain is at about 5.745" measured in 4 different places. Axle is almost dead center in hub and only off by about 3-4 thousandths. 

Sent using my fat thumbs!


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## Danielrg_usa (Feb 12, 2011)

Took my derailleur off because I noticed some play between it and the hanger. It seemed that the pivot was.loose or worn. Bolt attaching derailleur to hanger was nice and tight as expected. However, when I pulled it off the threads in the hanger looked like $&!t. Went to put it back on just till I can get a new one here and that isn't happening. It wants to cross thread all sorts of differnet ways. Maybe ill just become a single speeder like I have thought about. Oh the simplicity.

Sent using my fat thumbs!


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## ThundaCrymz (Oct 22, 2012)

:O So is your hanger threading stripped???? That actually happened to one of my current rides, i was able to use a Chainring bolt and fastener and use a different derrailleur to fasten it onto the hanger.


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## Bill in Houston (Nov 26, 2011)

Danielrg_usa said:


> Went to put it back on just till I can get a new one here and that isn't happening. It wants to cross thread all sorts of differnet ways. Maybe ill just become a single speeder like I have thought about.


Oh, man, so sorry to hear that.

Before you go singlespeed for the sake of simplicity, hang out in the ss forum for a while.


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## Danielrg_usa (Feb 12, 2011)

ThundaCrymz said:


> :O So is your hanger threading stripped???? That actually happened to one of my current rides, i was able to use a Chainring bolt and fastener and use a different derrailleur to fasten it onto the hanger.


Pretty much yea. There are a some scratches in my derailleur too. I probably hit it a couple too many times. The cage looks bent in towards the wheel too. When i took the chain off to check my high/low screws the top jocky wheel was just a little off but the bottom one buy a 1/4" or more.



Bill in Houston said:


> Oh, man, so sorry to hear that.
> 
> Before you go singlespeed for the sake of simplicity, hang out in the ss forum for a while.


Good idea! I know single speed is a big commitment, especially for noob like me still working on my cycling legs. Oh well. I have already been checking conversion kit prices and looks like it will be cheaper thank I thought. Cheaper than fixing my current set up too since I'm sure my derailleur is bent and I need a new one. Is it acceptable to post noob questions in the SS forum? SS related questions that is.

Sent using my fat thumbs!


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## Jammy9398 (Oct 29, 2012)

This is more of a question. do u guys suggest doing your repairs own repairs when possible? Is so, how difficult is it to replace a cassette and chain?? I find that buying the parts over th interns is much cheaper than Lbs.....yr advise is well appreciated!!!!!!! Thanks. I I cu?rrently have a 9 ring Cass. with a mid front ring and mrp chain guide. Any suggestions on Cass and chain.....???????? thanks


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## Jammy9398 (Oct 29, 2012)

This is more of a question. do u guys suggest doing your repairs own repairs when possible? Is so, how difficult is it to replace a cassette and chain?? I find that buying the parts over th interns is much cheaper than Lbs.....yr advise is well appreciated!!!!!!! Thanks. I I cu?rrently have a 9 ring Cass. with a mid front ring and mrp chain guide. Any suggestions on Cass and chain.....???????? thanks


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## shibiwan (Sep 2, 2012)

Jammy9398 said:


> This is more of a question. do u guys suggest doing your repairs own repairs when possible? Is so, how difficult is it to replace a cassette and chain?? I find that buying the parts over th interns is much cheaper than Lbs.....yr advise is well appreciated!!!!!!! Thanks. I I cu?rrently have a 9 ring Cass. with a mid front ring and mrp chain guide. Any suggestions on Cass and chain.....???????? thanks


It's not difficult at all, especially so when you're mechanically inclined and know how to use a wrench.

You'll need the following special tools for what you want to do:
Park Tool Co. » FR-5 : Cassette Lockring Tool : Freewheel & Cassette

Park Tool Co. » HCW-16 : Chain Whip / 15mm Pedal Wrench : Freewheel & Cassette

Topeak Super Chain Tool > Accessories > Tools > Chain tools | Jenson USA Online Bike Shop


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## Jammy9398 (Oct 29, 2012)

One thing I forgot to mention is, the rear derailleur is a Shimano XT.. Should I buy a Shimano Deore XT Cassette?? any suggestions?? I have read to pair this to an Sram chain with the (Power lock???)


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## shibiwan (Sep 2, 2012)

Jammy9398 said:


> One thing I forgot to mention is, the rear derailleur is a Shimano XT.. Should I buy a Shimano Deore XT Cassette?? any suggestions?? I have read to pair this to an Sram chain with the (Power lock???)


You can use any Shimano compatible cassette (just make sure it's the same number of speeds). XT is pretty good, XTR is better but costs more. The SRAM PG-990, PG-980, PG-970 etc will all fit and run fine. I prefer the PG-990 to be honest - the spider cage design is better overall.

Chain wise, you can use any 9-speed chain on your 9-speed setup. Many of us here will recommend the Shimano 7701 but it is harder to connect/reconnect as it uses pins instead of the powerlink/missing link. The SRAM chain will work fine too, so will the KMC ones and both of those come with the Powerlink (SRAM) or Missing Link (KMC). You'll still need the chain tool to break/cut the chains but will not need any tools to reconnect the chains with the Powerlink.

-S


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## Bill in Houston (Nov 26, 2011)

Danielrg_usa said:


> Is it acceptable to post noob questions in the SS forum? SS related questions that is.


Seems like it would be fine, as long as it looked like you had looked through old threads before starting a new one.


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