9 Speed Ultegra Chain Skip

sansabar said:

The two outside gears on the rear cassette of my Ultegra 9 speed have an ocassional skip as if they are trying to shift.
The chain and cassette are clean and the chain has no stretch. It shifts smoothly in all gears and have no issues with the front deraileur.
Is it possible to correct and adjust for these two gears without effecting the others?

is the derallier cage bent at all? how about the derallier hanger? is it straight?

Rideastrong said:

is the derallier cage bent at all? how about the derallier hanger? is it straight?

Everything appears straight. Never hit or dropped. All shifts are immediate with no drag. The rattle begins after a few strokes in the outer two gears. It hasn't jumped yet but it is enough to keep me in the saddle.
While the bike is on the stand I have looked down the cassette when in these gears and the chain is slightly rubbing on the preceding gears, but stops doing this once it is shfted to the third gear.

are you on the big ring at the front?

sansabar said:

Everything appears straight. Never hit or dropped. All shifts are immediate with no drag. The rattle begins after a few strokes in the outer two gears. It hasn't jumped yet but it is enough to keep me in the saddle.
While the bike is on the stand I have looked down the cassette when in these gears and the chain is slightly rubbing on the preceding gears, but stops doing this once it is shfted to the third gear.

If you derailer hanger and derailer are straight, and the upper and lower presets on the derailer are fine, you could play so ever slightly with the cable tension. But also check to make sure the cassette is still snug onto the cassette body. It is rare that these come loose, but it wold hurt to check it. If it is loose it will cause irradic shifting.

Are you sure that these 2 gears are not overly worn? Also how many teeth on these gears? If it is the 11, 12, 13, 14 tooth cogs these ones will skip easier when worn that the larger cogs just due to the number teeth in contact with the chain.

gclark8 said:

are you on the big ring at the front?

It seems the same both ways.

gclark8 said:

are you on the big ring at the front?

like Gclark is asking. if you are in the large front ring, you might just be cross chained and if so i would expect some rubbing.

Rideastrong said:

If you derailer hanger and derailer are straight, and the upper and lower presets on the derailer are fine, you could play so ever slightly with the cable tension. But also check to make sure the cassette is still snug onto the cassette body. It is rare that these come loose, but it wold hurt to check it. If it is loose it will cause irradic shifting.

Are you sure that these 2 gears are not overly worn? Also how many teeth on these gears? If it is the 11, 12, 13, 14 tooth cogs these ones will skip easier when worn that the larger cogs just due to the number teeth in contact with the chain.

The teeth are not worn. I am beginning to develop some concern as I am planning on putting a lot of miles on this bike (used LeMond Buenos Aires/ex cond). I have recently replaced the crankset and bottom bracket (172.5 to 170) and am not against changing out the derailleur "just in case". Should I decide to change out the derailleur would I benefit any upgrading to a dura ace 7700 from the ultegra 6500? And if I moved to a DA would I need to change out the chain?

Rideastrong said:

like Gclark is asking. if you are in the large front ring, you might just be cross chained and if so i would expect some rubbing.

Most of the riding is in the small ring.

sansabar said:

The teeth are not worn. I am beginning to develop some concern as I am planning on putting a lot of miles on this bike (used LeMond Buenos Aires/ex cond). I have recently replaced the crankset and bottom bracket (172.5 to 170) and am not against changing out the derailleur "just in case". Should I decide to change out the derailleur would I benefit any upgrading to a dura ace 7700 from the ultegra 6500? And if I moved to a DA would I need to change out the chain?

If you derailler is in good condition, ie the bushings are snug, and the cage is straight there is no real reason to change it. Going from Ultegra to D/A isn;t a huge difference other than the weight of your wallet after you buy the D/A. You mentioned you recently replaced the crankset and BB with new ones. Did you go from a triple to double or always have a double? If you went from a triple to double you probbaly have a long cage rear derailer and that 'might' cause some sloppy shifting. You always want to use the shortest cage rear derallier you can.

Also can you tell me what tooth config on the rear cassete you are using and how many teeth on the cog where it is rubbing?

Rideastrong said:

If you derailler is in good condition, ie the bushings are snug, and the cage is straight there is no real reason to change it. Going from Ultegra to D/A isn;t a huge difference other than the weight of your wallet after you buy the D/A. You mentioned you recently replaced the crankset and BB with new ones. Did you go from a triple to double or always have a double? If you went from a triple to double you probbaly have a long cage rear derailer and that 'might' cause some sloppy shifting. You always want to use the shortest cage rear derallier you can.

Also can you tell me what tooth config on the rear cassete you are using and how many teeth on the cog where it is rubbing?

Went from double to double(identical Ultegras). No problems, just wanted to force a higher spin rate with the 170s and changed the bottom bracket while I was at it.
I'm running a 12-27 and the 12 and 13 are where the skip is occuring.

sansabar said:

Went from double to double(identical Ultegras). No problems, just wanted to force a higher spin rate with the 170s and changed the bottom bracket while I was at it.
I'm running a 12-27 and the 12 and 13 are where the skip is occuring.

I am not suprized you are seeing a little rubbing in the 12-13 when using the 39 in the front. It is pretty common. You are at the max cross chain for the 39. You may not have seen it with your old crankset/bb because they could have shifted the offset just slightly.

If you are indeed skipping that is beacuse of a couple things, the cogs are worn and the chain is not making good contact (those lower cogs don;t have many teeth in contact when spinning, or the derailler is not aligned properly in those gears. If you look stright down from the top, the casette cog, and the pully should be straight. You could play with cable tension slightly, but likely that will affect the quality of shifting in the 23-27 combinations. Instead of using the 12-13-14 with the 39 shift to the 53 and use the combinations avaliable there. A 53-19 and a 53-17 will be very similar and will still allow you to spin at the rate you want.

If you are skipping i still think those cogs could be a little too worn to mesh correctly with your chain. Or your chain is too worn to mesh with the cassette. It is really hard to tell how worn those 2-3 lower cogs are when looking at them. See if you can borrow a cassette form someone and see if it fixes the problem. If you were local i would lend you a cassette to see if that issolates the problem.

Rideastrong said:

I am not suprized you are seeing a little rubbing in the 12-13 when using the 39 in the front. It is pretty common. You are at the max cross chain for the 39. You may not have seen it with your old crankset/bb because they could have shifted the offset just slightly.

If you are indeed skipping that is beacuse of a couple things, the cogs are worn and the chain is not making good contact (those lower cogs don;t have many teeth in contact when spinning, or the derailler is not aligned properly in those gears. If you look stright down from the top, the casette cog, and the pully should be straight. You could play with cable tension slightly, but likely that will affect the quality of shifting in the 23-27 combinations. Instead of using the 12-13-14 with the 39 shift to the 53 and use the combinations avaliable there. A 53-19 and a 53-17 will be very similar and will still allow you to spin at the rate you want.

If you are skipping i still think those cogs could be a little too worn to mesh correctly with your chain. Or your chain is too worn to mesh with the cassette. It is really hard to tell how worn those 2-3 lower cogs are when looking at them. See if you can borrow a cassette form someone and see if it fixes the problem. If you were local i would lend you a cassette to see if that issolates the problem.

Thanks for the input. I'm probably going to change out the derailleur and look into another rear cog. It may not be absolutely necessary but the bike does have about 2K on it and most of the other components are new. If nothing else I'll have backup parts. Thanks for the help.

Scott

sansabar said:

Thanks for the input. I'm probably going to change out the derailleur and look into another rear cog. It may not be absolutely necessary but the bike does have about 2K on it and most of the other components are new. If nothing else I'll have backup parts. Thanks for the help.

Scott

Scott - sounds good. like you said atleast you will have spare parts. If you buy a new cassette please buy a new chain. Also don't waste the money on the D/A stuff. I have both D/A and Ultegra and my Ultegra is just is good and about half the price of D/A. Also do you need the 12-27? Would a 12-25 work? If you use a 12-25 you can get away with a shorter derailer which will yeild crisper shifts. With the 27 you really should run the longer cage.

<li>12-25
12,13,14,15,17,19,21,23,25<li>12-27
12,13,14,15,17,19,21,24,27

Rideastrong said:

Scott - sounds good. like you said atleast you will have spare parts. If you buy a new cassette please buy a new chain. Also don't waste the money on the D/A stuff. I have both D/A and Ultegra and my Ultegra is just is good and about half the price of D/A. Also do you need the 12-27? Would a 12-25 work? If you use a 12-25 you can get away with a shorter derailer which will yeild crisper shifts. With the 27 you really should run the longer cage.

<li>12-25
12,13,14,15,17,19,21,23,25<li>12-27
12,13,14,15,17,19,21,24,27

That's an excellent idea. I'm not competing, just enjoying getting back into cycling after several years off. The only component "upgrade" I made was to move from a 105 to an Ultegra BB. Now I am Ultegra throughout. Think I'll look into a 12-25. Is there any difference in chain length should I move to a 12-25 from a 12-27?

sansabar said:

That's an excellent idea. I'm not competing, just enjoying getting back into cycling after several years off. The only component "upgrade" I made was to move from a 105 to an Ultegra BB. Now I am Ultegra throughout. Think I'll look into a 12-25. Is there any difference in chain length should I move to a 12-25 from a 12-27?

if you use a 12-25 and the shorter cage derailer your chain will be shorter.

Rideastrong said:

if you use a 12-25 and the shorter cage derailer your chain will be shorter.

Thanks for all of your help. I certainly have jumped back in with both feet!

Also, the new BB and crankset, are they 9 speed? 10 is different.

gclark8 said:

Also, the new BB and crankset, are they 9 speed? 10 is different.

Both 9 speed. Went from double 172.5 to double 170 Ultegra. No issues, just wanted to force a higher spin rate with the 170s and changed the bottom bracket (105 double to ultegra double) while I was at it.

OK, check the chain for wear with a gauge and inspect the cassette also. Consider a 13-23 or 13-25 cassette, that will force the cadence up too. I had almost never used my 12 and only occasionally the 25 so replaced it with a 13-23, now no more 16t & 18t gaps. 🙂