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Chain Slipping on Rear Sprocket! Causes?

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Thrasher

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Discussion starter · #1 ·
Hi, I've been having some major issues with my 05 Kona Dawg Deelux ever since I replaced the rear derailleur last fall.

I bought a Shimano GS Shadow Medium Cage derailleur and had it installed. It's supposed to be compatible with the 11-32 SRAM Cassette I bought so I figured it would not cause any shifting or gearing issues. Well, after that was installed I've been having issues with the chain slipping all over on the rear Cassette quite a bit! It's very annoying and can be dangerous when I'm riding at the resorts and hitting stunt features,etc. It's like it can't decide which gear it should be in.

Well, I decided to buy a new Crankset (Race Face AM) to see if that helped. After those were installed the issue only got worse! So, that's when I decided a new Chain (Shimano) would be a good idea to try and help with slippage issue. The new chain didn't help at all and probably made it worse. So, I then Bought a new Rear Cassette (SRAM). From what I've read all these components should work fine together.

Each time I take it to a shop for a derailleur adjustment it seems to shift ok and not slip until the moment I hit the trails and things get rough. I even had them use the Alignment tool to verify the derailleur is properly aligned. They didn't notice any Alignment issues so I should be fine with that.

I've had multiple shops do derailleur adjustments and it's not helping. A few days ago they replaced the derailleur housing and put a new cable on so I'm hoping that helps but am doubtful. The shop *thinks* I should be ok now and said I probably just didn't have enough length on the cable and it didn't allow from proper tension or something?

I've basically spent the whole summer dealing with this and it's really starting to piss me off! :madman: :madmax:

So, after replacing my whole drive train what do you think could be causing this chain slipping problem? It seems to happen a lot when I'm on middle front and middle-ish gears on the rear. The guys at the shop said the next thing to try would be the cassette free hub or something (The thing the rear cassette slides onto).

I'd appreciate any/all insight into this issue since it's ruining my riding experience and pissing me OFF!
 
#4 ·
How new is the cassette?
How new is the chain?
Were the cassette and chain purchased/installed at the same time?
Is the cable AND cable housing both new?
Have you made sure the cable housing is sitting flush and perfect in each mount point on the frame and at the shifter on the handlebars?
Have you checked the chain for any stiff links? Make sure every single link flows nicely.
Have you checked your rear derailleur hanger for misalignment?


About the above questions: If you don't replace your chain for long periods of time, as the chain stretches it'll begin to wear a wider pitch in between each tooth of the rear cogs. As a result, when a new chain is put on with the old cassette, the pitch is off and it can cause skipping under load. It's advised to check your chain relatively regularly for stretch. It's been said that if you lube your chain properly and check up on it, it should not only last you a decent length of time, but some users report getting 3 chains (when changed at proper times) per cassette, before having to buy a new cassette. With how cheap cassettes are about 75% of the time I just bite it and buy a new cassette anyways when I replace the chain, but everybody is different.

Recently I had some derailleur adjustment issues, where it would be perfectly sync'd with the bottom 5-6 cogs but the 2nd cog would experience a ton of chain chatter. I thought my indexing was off at my shifters, but they were brand new and I found this unlikely. Ultimately I took the cable off (which was also brand new) along with the housing. In the process I discovered my housing @ the shifter was not sitting flush, which lead me to believe that it's offset in the fitting was causing the weirdness I was seeing. Once re-adjusted, my rear derailleur was fine.

Earlier this year I was riding my hardtail, which at the time had a lower end Alivio derailleur. It was a good around-town bike, but I was getting a ton of chain skip under load, even with completely new drivetrain, cable, etc. Ultimately it turns out the derailleur itself had a misalignment, something about the parallelogram of the derailleur was offset. I discovered this by putting a new derailleur on and it solving ALL of my issues. Granted, the Alivio took a few hits from nasty spills, but my hanger was checked so I knew that was fine. Ultimately it turns out the derailleur needed to be changed. Not sure if that's your issue since your's is new, but I wanted to get this on the table so my experience can be heard by others in case it helps them out.

As we all know, stiff links can cause a lot of drivetrain issues. Take the time to sift through each link and make sure there is no tugging. Also your derailleur hanger can play a key part in causing the issues you're seeing, so make sure that it's checked. A lot of shops charge only a few dollars to check/realign it. In my case whenever I've gotten my hanger checked and it was fine, there was no charge.

There's a solution out there for your issue brah. We'll get it. Just post back and fill us in with the details.
 
Discussion starter · #6 ·
Thanks for the detailed Reply Roasted!

Roasted said:
How new is the cassette? Brand New 11-32 SRAM - Bought it right after I had my new crankset installed since it was slipping. Barely road at all with my New Chain/Cranks on the Old Cassette because I was worried the chain might try and "set" to the old Cassette.
How new is the chain? Brand New Shimano
Were the cassette and chain purchased/installed at the same time? As mentioned above I purchased them about 2 weeks apart but I didn't really ride at all since I wanted the chain to set to the new cassette.
Is the cable AND cable housing both new? Yep, they replaced that brand new the other day.
Have you made sure the cable housing is sitting flush and perfect in each mount point on the frame and at the shifter on the handlebars? The mount points look pretty flush to me.
Have you checked the chain for any stiff links? Should not be an issue on new chain but I can double check.Make sure every single link flows nicely.
Have you checked your rear derailleur hanger for misalignment? Yes, the shop used a tool to check that the other day and did not mention any alignment issues.

About the above questions: If you don't replace your chain for long periods of time, as the chain stretches it'll begin to wear a wider pitch in between each tooth of the rear cogs. As a result, when a new chain is put on with the old cassette, the pitch is off and it can cause skipping under load. It's advised to check your chain relatively regularly for stretch. It's been said that if you lube your chain properly and check up on it, it should not only last you a decent length of time, but some users report getting 3 chains (when changed at proper times) per cassette, before having to buy a new cassette. With how cheap cassettes are about 75% of the time I just bite it and buy a new cassette anyways when I replace the chain, but everybody is different.

Recently I had some derailleur adjustment issues, where it would be perfectly sync'd with the bottom 5-6 cogs but the 2nd cog would experience a ton of chain chatter. I thought my indexing was off at my shifters, but they were brand new and I found this unlikely. Ultimately I took the cable off (which was also brand new) along with the housing. In the process I discovered my housing @ the shifter was not sitting flush, which lead me to believe that it's offset in the fitting was causing the weirdness I was seeing. Once re-adjusted, my rear derailleur was fine.

Earlier this year I was riding my hardtail, which at the time had a lower end Alivio derailleur. It was a good around-town bike, but I was getting a ton of chain skip under load, even with completely new drivetrain, cable, etc. Ultimately it turns out the derailleur itself had a misalignment, something about the parallelogram of the derailleur was offset. I discovered this by putting a new derailleur on and it solving ALL of my issues. Granted, the Alivio took a few hits from nasty spills, but my hanger was checked so I knew that was fine. Ultimately it turns out the derailleur needed to be changed. Not sure if that's your issue since your's is new, but I wanted to get this on the table so my experience can be heard by others in case it helps them out.

As we all know, stiff links can cause a lot of drivetrain issues. Take the time to sift through each link and make sure there is no tugging. Also your derailleur hanger can play a key part in causing the issues you're seeing, so make sure that it's checked. A lot of shops charge only a few dollars to check/realign it. In my case whenever I've gotten my hanger checked and it was fine, there was no charge.

There's a solution out there for your issue brah. We'll get it. Just post back and fill us in with the details.
Click to expand...
At this point I'm leaning towards the rear derailleur because it seems like that was the start of the problems. I'm pretty upset about this and will probably avoid Shimano derailleurs from here on out if it's the cause of my issues. The derailleur has not taken any abuse since it was installed so it might be defective or something. I also found this website that mentions top reasons for chain slipping.
http://www.webmountainbike.com/toptencausof.html

**see my answers above**

I'm thinking it could have to do with the free hub as well. I'm going to take the rear tire off my other bike and try it to see if it makes a difference. I've never experience so much frustration before with a bicycle. :madmax:
 
#7 ·
The cable housing length may be incorrect as well, if the shop that installed the derailleur made the housing too short, the derailleur may move when the suspension cycles.

Also the Shadow derailleurs have had some issues on some brands of derailleur hangers where the B tension bolt stop doesn't provide enough range of adjustment.

If everything started with the change to a Shadow style derailleur, that would be two things worth checking into.
 
#9 ·
Thrasher said:
Hi, I've been having some major issues with my 05 Kona Dawg Deelux ever since I replaced the rear derailleur last fall.

I bought a Shimano GS Shadow Medium Cage derailleur and had it installed. It's supposed to be compatible with the 11-32 SRAM Cassette I bought so I figured it would not cause any shifting or gearing issues. Well, after that was installed I've been having issues with the chain slipping all over on the rear Cassette quite a bit! It's very annoying and can be dangerous when I'm riding at the resorts and hitting stunt features,etc. It's like it can't decide which gear it should be in.

Well, I decided to buy a new Crankset (Race Face AM) to see if that helped. After those were installed the issue only got worse! So, that's when I decided a new Chain (Shimano) would be a good idea to try and help with slippage issue. The new chain didn't help at all and probably made it worse. So, I then Bought a new Rear Cassette (SRAM). From what I've read all these components should work fine together.

Each time I take it to a shop for a derailleur adjustment it seems to shift ok and not slip until the moment I hit the trails and things get rough. I even had them use the Alignment tool to verify the derailleur is properly aligned. They didn't notice any Alignment issues so I should be fine with that.

I've had multiple shops do derailleur adjustments and it's not helping. A few days ago they replaced the derailleur housing and put a new cable on so I'm hoping that helps but am doubtful. The shop *thinks* I should be ok now and said I probably just didn't have enough length on the cable and it didn't allow from proper tension or something?

I've basically spent the whole summer dealing with this and it's really starting to piss me off! :madman: :madmax:

So, after replacing my whole drive train what do you think could be causing this chain slipping problem? It seems to happen a lot when I'm on middle front and middle-ish gears on the rear. The guys at the shop said the next thing to try would be the cassette free hub or something (The thing the rear cassette slides onto).

I'd appreciate any/all insight into this issue since it's ruining my riding experience and pissing me OFF!
Click to expand...
First, it sounds like a ghost shifting problem (not staying on the selected cog), not that the chain is slipping (jumping teeth on the cog).

Causes to check:
Incompatible shifter.
Improper cable adjustment.
Misaligned dérailleur hanger.
Improper cable housing length.
Worn/dirty/damaged cable and housing.

I had ghost shifting on a bike for 6 months until I swapped out the fancy high end housing for plain old bulk SIS housing. No problems for a year now.
 
#10 ·
On top of what all the other guys are suggesting, look for bent chainrings, bent cassette gears, loose cassette, sticking shifter mechanism, sticking or slipping freewheel.....

Using a magic marker, put a little black mark on the side of your chain exactly where it jumped off the gear. Then check it several times to see if the chain is jumping off at the same point. If so, its the chain.

Is it jumping off on any gear or just one or a few? If so, that could indicate worn or faulty gear teeth on the cassette.

Good luck!
 
Discussion starter · #11 ·
rockyuphill said:
The cable housing length may be incorrect as well, if the shop that installed the derailleur made the housing too short, the derailleur may move when the suspension cycles.

Also the Shadow derailleurs have had some issues on some brands of derailleur hangers where the B tension bolt stop doesn't provide enough range of adjustment.

If everything started with the change to a Shadow style derailleur, that would be two things worth checking into.
Click to expand...
Hi rockyuphill, Thanks a lot for this info! I went upto the shop (LBS) today and mentioned it was slipping right away after their recent work to try and correct this issue. One of the techs did a the simple barrel cable adjustment stating that might be it. I mentioned that wouldn't fix the issue but was worth adjusting. Then, one of the other techs was talking about the Cassette saying since I ride Downhill hard and XM on my bike I probably should have went with a higher-end Rear cassette like and S-RAM he showed me that had a Plastic re-enforcement bracket built into the back. I mentioned that mine should be fine since it's brand new and I never had one with a Plastic re-enforcement bracket before. I mentioned the Free hub as being a potential issue and he thinks mine is fine.

Then he reseated the Rear Cassette and tightened it down good. The techs weren't very busy so they were quite receptive to my issue since I mentioned it's been happening all summer and potentially dangerous when riding skinny stunt features at the resorts and stuff. They did a few more slight adjustments to derailleur and then I went out in front and test road. It seemed to be shifting good and not skipping around in the Middle front /middle-ish gears on the rear. I just went over to my local dirt jumps and did some riding as well. It seemed to be shifting quite well and not skipping but I'm still very skeptical!

When I first took the bike in to have them look at the derailleur they ended up replacing the Housing (which is the cable). He immediately mentioned that the length might be too short not allowing it to get re-tensioned correctly. So, I'm guessing since they replaced the housing/cable they probably made it the correct length? It looks ok from what I can tell? I've included a few pictures if that helps tell if it looks like the right *length*. Everything did seem to start with the shadow derailleur so I'll have to look into the B tension bolt you mention.

Appreciate all the advice since I really want to get this bike back on the trail where it belongs. It worked ok last weekend at the Resort doing downhill but I had to try and avoid those middle/middle gears which usually isn't hard to do when doing DH. ;)

I really like my Kona Dawg a lot so I want it dialed in again. Esp after replacing the Cranks/Cassette/Chain/pedals/grips/tire a few months ago. I'm hesitant to spend more at this point but sure hope I can get it dialed back in. I hate riding with slippage! :crazy:
 
#13 ·
Thrasher said:
Hi rockyuphill, Thanks a lot for this info! I went upto the shop (LBS) today and mentioned it was slipping right away after their recent work to try and correct this issue. One of the techs did a the simple barrel cable adjustment stating that might be it. I mentioned that wouldn't fix the issue but was worth adjusting. Then, one of the other techs was talking about the Cassette saying since I ride Downhill hard and XM on my bike I probably should have went with a higher-end Rear cassette like and S-RAM he showed me that had a Plastic re-enforcement bracket built into the back. I mentioned that mine should be fine since it's brand new and I never had one with a Plastic re-enforcement bracket before. I mentioned the Free hub as being a potential issue and he thinks mine is fine.

Then he reseated the Rear Cassette and tightened it down good. The techs weren't very busy so they were quite receptive to my issue since I mentioned it's been happening all summer and potentially dangerous when riding skinny stunt features at the resorts and stuff. They did a few more slight adjustments to derailleur and then I went out in front and test road. It seemed to be shifting good and not skipping around in the Middle front /middle-ish gears on the rear. I just went over to my local dirt jumps and did some riding as well. It seemed to be shifting quite well and not skipping but I'm still very skeptical!

When I first took the bike in to have them look at the derailleur they ended up replacing the Housing (which is the cable). He immediately mentioned that the length might be too short not allowing it to get re-tensioned correctly. So, I'm guessing since they replaced the housing/cable they probably made it the correct length? It looks ok from what I can tell? I've included a few pictures if that helps tell if it looks like the right *length*. Everything did seem to start with the shadow derailleur so I'll have to look into the B tension bolt you mention.

Appreciate all the advice since I really want to get this bike back on the trail where it belongs. It worked ok last weekend at the Resort doing downhill but I had to try and avoid those middle/middle gears which usually isn't hard to do when doing DH. ;)

I really like my Kona Dawg a lot so I want it dialed in again. Esp after replacing the Cranks/Cassette/Chain/pedals/grips/tire a few months ago. I'm hesitant to spend more at this point but sure hope I can get it dialed back in. I hate riding with slippage! :crazy:
Click to expand...
I have never seen any cassette with plastic reinforcement. None, SRAM (no "-") or not. The high end models have aluminum cog spiders (cog carriers), but it has no affect on the shifting and does not improve the shifting over loose cog cassettes.

Making sure the cassette was tight on the hub was good.

Adjusting the cable tension is SOP and is something every riders should know how to do. Very simple and normal adjustment.

The housing is not the cable. The cable runs inside the housing.
 
#15 ·
Let me just say, never assume that you don't have a stiff link. Your chain may be brand new - but guess what? You had to put the chain on somehow, right? It could be that the link you re-attached it at is stiff. You just never know - and something so simple shouldn't be overlooked. :thumbsup:
 
Discussion starter · #17 ·
shiggy & frdfandc, If this continues, I'll have them look into the length of the cable. I figured they would've made it the correct length but who knows!!??

However, I'm thinking that re-seating the cassette seriously helped!!! I also noticed they did some minor adjustment on one of the bolts on the back of the derailleur that might of been B Tension bolt rockyuphill mentioned??

I haven't gone on any serious hard trail riding yet but I went on a decent ride around the neighborhood and hit my dirt jumps and it's held up pretty solid which is MUCH more than I can say for how it's been acting all summer!!

fixbikeguy, I think the suspension pivot bolts are fine.

shiggy, yeah, what he showed me looked like a plastic re-enforcement bracket. It's something I never recall seeing on a cassette and probably would tighten up shifting a little but nothing I need. I figured the housing and cabling were different. I seriously need to take some time to learn more about derailleurs and doing basic maintenance so I don't have to go to the shop every time I need a minor adjustment. I'll do some research and learn how to tighten the tension on my cabling. The symptoms of my issue is a ghost shifting problem so that's more accurate. Again, thanks for all the things to look into. I think most of the things you've mentioned to check have been checked and *should* be fine. Pretty crazy hearing how your housing caused your ghost shifting issues!

Mike Gager, I think I'll look into those Jocky Wheels in the future for a smoother drive train!

ambassadorhawg & Roasted, my cassette and chain should be fine since they are new and I was avoiding riding as much as possible while it was have this slipping issue! Good to know how to try and trouble-shoot the chain though.

I'm seriously hoping the re-seat of the cassette in addition to the slight bolt derailleur adjustment they did fixes my issue. I'll be doing some serious riding soon with the nice fall weather so I'll report back.

Thanks a lot for all the insight and suggestions into this issue. I was getting really sick and tired of going to all these shops trying to have *adjustments* made only to have it go right back to slipping. This has been going on all summer and I'm sick of it! Luckily I have another bike I was able to rip it up on this summer!
 
Discussion starter · #19 ·
Scotth72 said:
The cable housing from the front triangle to the rear triangle is too short. Looks like it might be hanging up on the top of the suspension linkage, and altering tension.
Click to expand...
Yeah, that seem to be the consensus based off my pictures. If I continue to have issues with this I'm going to make them re-lengthen the cable since I just paid to have the housing and cabling redone.
 
#20 ·
Looking at the second picture, it does kinda look like the run is a tad short.
But I think that possibly having the rear cable run on the outside cable stops could help solve the issue as well.
What it looks like could possibly be happening is when the rear suspension is compressed, the rear cable run is hanging up on the seat collar, causing a ghost shift.
I've seen this before.
If the cable is about an inch or so longer, and positioned on the outside cable stops, it will have more clearance to not catch on the seat clamp.
It also looks like your seat clamp is crooked, and the lever could be getting in the way.

It is hard to tell from the pics though. If we had a pic that was taken from a more level perspective of the second cable run, it would be easier to tell.

Also, with the design of the kona frame with those long rocker links, it can be more sensetive to cable housing length than other frame designs.
 
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