Sunrace Cassette and Deore Question
#1
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Sunrace Cassette and Deore Question
I am trying to fix a shifting problem on my Burley. The bike is factory equipped with a Taigra STi's, Deore rear derailer and a Sunrace 9-speed 11-32 cassette. The chain is a SRAM pc951 chain. I have adjusted the cables to get a perfect upshift(from small to big) but when I try to go down through the cassette the chain will stay on the cog it was on until I have shifted down twice. The chain will then go down 2 gears so I have to upshift one to get my desired gear ratio. If I only click down one gear nothing really happens except a bit of noise until I shift a second time. Anyone else had this issue? I am thinking maybe it is just a miss match combo but really the only thing non factory is the SRAM chain.
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What he said . . . or something else
Yes, it might be something binding between the cable and housing (a burr, kink, friction). You might try dripping a little chain lube into the housing.
Or, it might be too much adjustment. You might have made the downshifting (shifting to larger cogs / easier gears) TOO good. I've worked on indexed shifting systems before and got them where they seemed to shift flawlessly from smaller to larger cogs, but then they wouldn't shift back without hesitating.. Screwing the adjusting barrel back in a turn or 2 usually balanced things out.
Rich
Or, it might be too much adjustment. You might have made the downshifting (shifting to larger cogs / easier gears) TOO good. I've worked on indexed shifting systems before and got them where they seemed to shift flawlessly from smaller to larger cogs, but then they wouldn't shift back without hesitating.. Screwing the adjusting barrel back in a turn or 2 usually balanced things out.
Rich
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Asides of possible cable/housing issue mentioned, some lube on the STI inner workings could help.
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A couple of thoughts...
Terminology: Even though the chain is being move "up" the cassette, upshifting is technically the opposite... you upshift into gears that are "harder to push" and you downshift into gears that are "easier to push". I understood what you were trying to say, but it's worth while to keep the terminology straight or -- if you're like me -- limit your comments to describing what the chain is doing which you also did.
OK..... Question Time
1. Was it working well to begin with on the road when you took possession from KnoxBreezer?
2. If not, what was the chain doing as it ran up and down the cassette before you started to adjust it, in what direction, and between which number sprocket(s) (e.g., moving up from 2nd to the 3rd smallest sprocket).
3. What all did you adjust or change?
4. Have you been doing all of your adjusting in the workstand without any resistance on the rear wheel or have you road tested it with your stoker to see how it is shifting under load?
5. Before doing anything else, have you made sure that the B-screw is adjusted correctly? If you aren't sure, take a few minutes to review the infomation on Park Tool's rear derailleur adjustment "how-to" guide:
https://www.parktool.com/repair/readhowto.asp?id=64
Anxiously awaiting your feedback (well, not really... but feel free).
Terminology: Even though the chain is being move "up" the cassette, upshifting is technically the opposite... you upshift into gears that are "harder to push" and you downshift into gears that are "easier to push". I understood what you were trying to say, but it's worth while to keep the terminology straight or -- if you're like me -- limit your comments to describing what the chain is doing which you also did.
OK..... Question Time
1. Was it working well to begin with on the road when you took possession from KnoxBreezer?
2. If not, what was the chain doing as it ran up and down the cassette before you started to adjust it, in what direction, and between which number sprocket(s) (e.g., moving up from 2nd to the 3rd smallest sprocket).
3. What all did you adjust or change?
4. Have you been doing all of your adjusting in the workstand without any resistance on the rear wheel or have you road tested it with your stoker to see how it is shifting under load?
5. Before doing anything else, have you made sure that the B-screw is adjusted correctly? If you aren't sure, take a few minutes to review the infomation on Park Tool's rear derailleur adjustment "how-to" guide:
https://www.parktool.com/repair/readhowto.asp?id=64
Anxiously awaiting your feedback (well, not really... but feel free).
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Also, especially with a tandem, because of the extra long cables and frame, it might be adjusted just fine empty, but when loaded, the frame sags a bit, pulling the cables a little tighter. Therefore, you may have to tweak it "on the fly." Tandems are persnickity that way.
#7
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Originally Posted by Old Hammer Boy
when loaded, the frame sags a bit, pulling the cables a little tighter. Therefore, you may have to tweak it "on the fly." Tandems are persnickity that way.
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#8
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Originally Posted by TandemGeek
OK..... Question Time
1. Was it working well to begin with on the road when you took possession from KnoxBreezer?
1. Was it working well to begin with on the road when you took possession from KnoxBreezer?
Originally Posted by TandemGeek
2. If not, what was the chain doing as it ran up and down the cassette before you started to adjust it, in what direction, and between which number sprocket(s) (e.g., moving up from 2nd to the 3rd smallest sprocket).
Originally Posted by TandemGeek
3. What all did you adjust or change?
Originally Posted by TandemGeek
4. Have you been doing all of your adjusting in the workstand without any resistance on the rear wheel or have you road tested it with your stoker to see how it is shifting under load?
Originally Posted by TandemGeek
5. Before doing anything else, have you made sure that the B-screw is adjusted correctly? If you aren't sure, take a few minutes to review the infomation on Park Tool's rear derailleur adjustment "how-to" guide:
https://www.parktool.com/repair/readhowto.asp?id=64
https://www.parktool.com/repair/readhowto.asp?id=64
Originally Posted by TandemGeek
Anxiously awaiting your feedback (well, not really... but feel free).
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Reinforcement....
1. The closer the upper jockey wheel is to your cogs as it travels up and down the cassette, the more precise the shifting will be. The "B Screw" should be nearly all the way in, as illustrated on Park's web site given that you have a 32t, even closer to being all the way in for a 34t. Something to keep in mind if you have reason to change the size of your rear cassette...
2. For tandems, more so than single bikes, you will need to make a final "tweak" to the rear derailleur using the in-line cable adjuster (found on bikes that use indexed shifting) while riding the tandem with a stoker. This has more to do with how the drive chain will perform while under the very high tension that is developed by a tandem team and less to do with potential frame flex-induced shifting issues which are fairly rare nowadays. Learn how to use your in-line adjusters while you're working on the bike in the stand so that you can make "on the fly" tweaks to dial out chain chatter... it doesn't usually take more than 1/2 a turn, but you need to be sure you're able to know which way to turn the adjuster's barrell to get the desired effect otherwise you may find that you make things worse, not better.
3. Anytime you cannot dial-out shifting problems with your rear derailleur, suspect a bent derailleur hanger and have a bike shop check it with an alignment tool.
1. The closer the upper jockey wheel is to your cogs as it travels up and down the cassette, the more precise the shifting will be. The "B Screw" should be nearly all the way in, as illustrated on Park's web site given that you have a 32t, even closer to being all the way in for a 34t. Something to keep in mind if you have reason to change the size of your rear cassette...
2. For tandems, more so than single bikes, you will need to make a final "tweak" to the rear derailleur using the in-line cable adjuster (found on bikes that use indexed shifting) while riding the tandem with a stoker. This has more to do with how the drive chain will perform while under the very high tension that is developed by a tandem team and less to do with potential frame flex-induced shifting issues which are fairly rare nowadays. Learn how to use your in-line adjusters while you're working on the bike in the stand so that you can make "on the fly" tweaks to dial out chain chatter... it doesn't usually take more than 1/2 a turn, but you need to be sure you're able to know which way to turn the adjuster's barrell to get the desired effect otherwise you may find that you make things worse, not better.
3. Anytime you cannot dial-out shifting problems with your rear derailleur, suspect a bent derailleur hanger and have a bike shop check it with an alignment tool.
Last edited by TandemGeek; 09-11-06 at 09:29 PM.
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Originally Posted by TandemGeek
3. Anytime you cannot dial-out shifting problems with your rear derailleur, suspect a bent derailleur hanger and have a bike shop check it with an alignment tool.
If you have a steel frame or the frame has a steel derailleur hanger, a hanger alignment tool is nice to have. I often pack one with me when I travel with the bike in a soft case, as the frame sometimes gets bashed in wierd ways in transit and you never know what's going to be bent at the other end of the trip. The derailleur hanger is pretty vulnerable to bending in transit.
- L.
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Originally Posted by TandemGeek
3. Anytime you cannot dial-out shifting problems with your rear derailleur, suspect a bent derailleur hanger and have a bike shop check it with an alignment tool.