# SRAM Red chain slip problem



## kyrider

After having the bike in the shop for warranty work I'm having problems with the chain slipping forward at random intervals. The chain is not jumping on a different cog it is slipping forward as if it skips teethes on the cassette or crank set. The bike shop swapped all components from the old frame to the new one. 

What I've done so far:
1. Checked RD: b-adjust screw, cable tension. Shifting is actually fine, no problems there.
2. Checked the cassette (1090-OG PowerDome) to make sure nothing is broken or loose. This cassette is not very old maybe 1000 miles on it.
3. Tried a different set of wheels (with the same cassette) to make sure it's not the free hub.
4. Changed the chain with a new one to rule out a worn chain.

My next step is to try a different cassette and maybe a new crank set if the problem persists. 

Any other ideas or advice of what else could it be?


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## kyrider

I forgot to mention that I also changed the cables with a kit of Yokozuna Reaction.


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## Guest

Describe what the chain is doing in greater detail if you can. Where is this happening, the chainrings, near the cassette? More info on what you are doing with the bike when happens may help as well.


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## kyrider

kytyree said:


> Describe what the chain is doing in greater detail if you can. Where is this happening, the chainrings, near the cassette? More info on what you are doing with the bike when happens may help as well.


I can't reproduce this "on demand" so it's hard to catch a glimpse of what's happening while I ride the bike, I can't watch the cassette at all times  
The only time I saw this happening it looked like the chain was on the same cog but was bumped up while coming from the back of the cassette towards the cranks. At that point it slipped forward 1 or 2 teethes. So, naturally I thought it was a stiff link so I checked the chain and after not finding any links w/ problems I changed it with a new one.

It happens at random times on flats, on hills or when I resume riding from a stop light. I could be riding out of saddle or in the saddle. Sometimes I can go for 30min w/o a problem and then boom 2-3 slips in a row very close to each other or just one slip every 10-15min.

It makes no sense to me what it could be...


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## Guest

From your description that sounds like its starting to change gears on the cassette, the "slip" being the normal raising or lowering of the chain when it shift except its not going far enough shift completely.

Are your shifts going up and down the cassette about the same or is there more hesitation or lag in one over the other?


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## kyrider

kytyree said:


> From your description that sounds like its starting to change gears on the cassette, the "slip" being the normal raising or lowering of the chain when it shift except its not going far enough shift completely.
> 
> Are your shifts going up and down the cassette about the same or is there more hesitation or lag in one over the other?


I don't have problems shifting, no delays in both directions, no chain rub on the cassette cogs.


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## Guest

Check any bolts around the dropouts or rear mech hanger for play, and that there is no play in the axle of your hub, lockring is tight and all gears firmly in place, and quick release properly closed.

Outside of that I don't know.


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## kyrider

kytyree said:


> Check any bolts around the dropouts or rear mech hanger for play, and that there is no play in the axle of your hub, lockring is tight and all gears firmly in place, and quick release properly closed.
> 
> Outside of that I don't know.


Thanks.

I'll check everything again and probably redo the RD installation and setup because I'm not sure how they did it at the shop. Better make sure it's properly done.


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## Guest

I've had bolts become loose back there before and it causes the cassette to move slightly, and its easy to think its something else because the tendency (at least for me) is to believe that all that is secure.


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## magic

Only in the big front ring? Have you checked the teeth behind the crank arm? On my RED front chain ring it had a few teeth damaged right behind the crank arm. The chain would randomly slip and on a specific range of rear gears really skip. Once I figured it our, I use a wrench to straighten out the couple of bad teeth and then just replaced the big front ring with a new FSA one. Not as sexy as the RED ring, but does work a lot better.


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## Kristatos

If you try kytyree's suggestions and everything checks out ok then the only thing I can think is it's a worn or defective cassette. I am not sure from reading through this thread if it's always happening in certain cogs or across the entire cassette? If it was certain cogs I'd check the tooth profile and see if the "valley" between the teeth seems wider than some of the other cogs where you don't have the problem. 1000 mi would be incredibly fast to wear out a cassette, but if you ride in the same gear a large percentage of the time and your chain was dirty maybe it could happen.


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## Jlitespeed

It seems that you are having the same problem I had. I swapped my Sram Red components over to a new bike. Also installed new Yokozuna cables and new Sram Red chain. The old one was trashed after only 1500 miles or so. 

Right off the bat, the chain was skipping big time when I put pressure on the drive train, small or big ring, it just skipped. The adjustments were good, shifting was spot on, no rubbing on the FD. The LBS put on a spare Dura Ace cassette and problems went away, rock solid. It looked the Sram Red (1090G 11-25) cassette was the problem, worn out with the same mileage as the chain. The teeth on the gears, 19-25 (mostly used) were rounding off on the top causing the chain not to hold and jump. A new Sram Red cassette came in and was swapped out and the chain skipping is gone and not missing a beat.

I'm finding out that the Sram Red chain and Red cassettes are not holding up compared to my old Dura Ace 7800 stuff. I thought I had lubed the drive train when needed but it looks like it was not enough??


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## paul l

I guess the comments rule out chain length. My first instinct reading the OP was chain too long and perhaps taking out a link or two but subsequent posts suggesting quality and wear are a shame. Hopefully SRAM will continue to work on the components that they fall behind Shimano and Campag where these reveal themselves over time.


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## kyrider

Jlitespeed said:


> It seems that you are having the same problem I had. I swapped my Sram Red components over to a new bike. Also installed new Yokozuna cables and new Sram Red chain. The old one was trashed after only 1500 miles or so.
> 
> Right off the bat, the chain was skipping big time when I put pressure on the drive train, small or big ring, it just skipped. The adjustments were good, shifting was spot on, no rubbing on the FD. The LBS put on a spare Dura Ace cassette and problems went away, rock solid. It looked the Sram Red (1090G 11-25) cassette was the problem, worn out with the same mileage as the chain. The teeth on the gears, 19-25 (mostly used) were rounding off on the top causing the chain not to hold and jump. A new Sram Red cassette came in and was swapped out and the chain skipping is gone and not missing a beat.
> 
> I'm finding out that the Sram Red chain and Red cassettes are not holding up compared to my old Dura Ace 7800 stuff. I thought I had lubed the drive train when needed but it looks like it was not enough??


Jlitespeed, on your setup what's the distance between the upper guide pulley and the edge of the smallest/largest cog? SRAM requires a min of 6mm but last night I tried to go with 5mm and it seemed to reduce the slip but not eliminate it completelly. At this point I think I'm gonna wait for the new cassette.

If it turns out the Red cassette is the problem I think SRAM needs to find a quick fix because the DA is way more durable, I have an 7800 on my Scott and it has 2000 miles and shifting is still crisp and no chain slip!


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## kyrider

paul l said:


> I guess the comments rule out chain length. My first instinct reading the OP was chain too long and perhaps taking out a link or two but subsequent posts suggesting quality and wear are a shame. Hopefully SRAM will continue to work on the components that they fall behind Shimano and Campag where these reveal themselves over time.


Chain length is ok, I think the problem is caused by cassette wear, the most used cogs in the middle of the cassette is where this problem happens. I think DA is still ahead as far as durability goes, so the next cassette will probably be a DA7900 which I heard works very well with Red group.


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## kyrider

*problem solved*

Just got the new cassette and everything works fine with it. Did a quick ride of 30miles w/o any problems. So it must have been the old cassette which was worn out after only 1350 miles  That's disappointing and I hope SRAM will address the issue.


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## LeBikeClub

I bought my SRAM RED brand new just a month ago, and the same chain slip problem described by many of you started to manifest itself on a couple of my gears (2nd and 3rd smallest cogs). I took it back to the dealer and they warrantied the Powerdome cassette, the replacement cassette solved that problem.


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## danahs

i just bought a "new" red cassette from ebay and I am having the same problem (very frustrating)


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## Taskmaxter

I'm wondering if this is the problem I'm experiencing. I only have 300 to 400 miles on my SRAM red rear derailluer and 11-28 cassette and I'm having problems with shifting moving up the rear cassette towards the bigger rings. From riding this weekend, it appears the when it moves up to a bigger ring the chain hasn't completely engaged the ring it is moving into and when turning the crank during the shift it will make a pop in the back when the chain finally engages the ring. The only way I can get consistency on the up shifts is to relax the pedal stroke when shifting with the rear derailluer. I've had the mechanics check it out and they say everything looks good.

Does this sound similar to what other folks are describing?


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## frdfandc

Is this a new bike, or new components with new cables?

Either way, you have probably some cable stretch to adjust out. Might need to give the barrel adjuster a 1/4 turn or so.

If you can, either have the LBS test ride the bike and make adjustments on the test ride, or find another shop that will. Shifting can be perfect on the workstand, but be 100% while actually riding the bike.


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## Taskmaxter

frdfandc said:


> Is this a new bike, or new components with new cables?
> 
> Either way, you have probably some cable stretch to adjust out. Might need to give the barrel adjuster a 1/4 turn or so.
> 
> If you can, either have the LBS test ride the bike and make adjustments on the test ride, or find another shop that will. Shifting can be perfect on the workstand, but be 100% while actually riding the bike.


Hey there - well, the bike has now got around 300 miles on it and I've had it into the LBS a couple of times to try to work out the kinks with the rear derailleur (just this weekend as well). You make a good point that they will probably need to test ride it since dialing it in on the stand doesn't seem to be resolving my issue. Seems like it has problems shifting under a load.


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## natedg200202

When the red cassette first came out, I saw the design as ingenious because it was lightweight, but made of steel, so my thinking was it should last a long time (compared to other lightweight cassettes from Campy / Shimano that use Ti Cogs). Looks like the reality is that the design of this cassette falls short with very quick wear intervals.


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## janiszew

Was the chain the original one being used with the cassette? Did you use a chain wear tool on it? Although 1350 miles still isn't a lot if you were doing lots of high force, low cadence riding it may have stretched the chain much faster than normal which subsequently wore the cassette out.


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## Devery

I got 3,000 miles out of my SRAM Red cassette. I probably would have gotten more if I would have invested in a chain tool because my chain was stretched (original chain). When I put the new chain on the skipping began. New chain and cassette, no skipping. I also bought a go-no go chain measuring tool because Red cassettes aren't cheap.


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## BikerBear

Hello Kyrider,

I have been having the same problem as you intermittently for a year now. For reference my background is in mechanical engineering. The condition is caused by the "missing" teeth (first 6 sprockets, largest to smallest) that SRAM left out on their "Red" cassettes to save weight. What appears to occur is that while pedaling and shifting gears at the same if a slight “bump” or jar in the road is encountered the chain will at that precise moment fall from one cassette sprocket to the next. When the chain happens to encounter the section of ‘missing” teeth on the next sprocket you get the “skip” sensation. Because a number of conditions need to happen all at the same time this issue is very intermittent. To also substantiate my observations take a look at the new RED cassette (2013 model), and you will notice that SRAM got smart and have all the teeth in each sprocket. And one last detail, I went and bought a XG1090 cassette (has no missing teeth) and the problem cannot be duplicated.

Hope this helps clarify the issue you’re having.


Regards,

Bikerbear


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