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#1
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Repair Sram twist shifter?
I have Sram 9.0 twist shifters and am having trouble with the rear
shifter. The shifter seems like it is not snapping to the center of the shift detent, so on certain gears I have to nudge it slightly to prevent noise and/or skipping. So two questions: One, what's the expected service life of these shifters? I'd say I have maybe 400 hours use on them in dry dusty conditions. Two, anything I can do to service the innards? |
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#2
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Repair Sram twist shifter?
On Sep 10, 3:50 pm, Dave wrote:
I have Sram 9.0 twist shifters and am having trouble with the rear shifter. The shifter seems like it is not snapping to the center of the shift detent, so on certain gears I have to nudge it slightly to prevent noise and/or skipping. So two questions: One, what's the expected service life of these shifters? I'd say I have maybe 400 hours use on them in dry dusty conditions. Two, anything I can do to service the innards? I've used SRAM for a number of years. Just in case the problem is not with your shifter, fastidiously check the rear derailleur hanger alignment. I've found SRAM indexing to be pretty tolerant of wear, dirt, dirty cables, etc., BUT I have occasionally had indexing problems. I tried a number of approaches to fixing these problems, and replacing the derailleur hanger restored the shifting quality (for my cases anyway). My hypothesis is that the rear derailleur hangers get a bit bent and that the geometry of the SRAM rear derailleurs makes them more sensitive than Shimano derailleurs to hanger misalignment. I never did manage to realign a bent hanger adequately, but then I've worked without the proper alignment tool in a poorly lit garage. I've never had a problem with the shifters. BP |
#3
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Repair Sram twist shifter?
Depends on the age of the shifters. Older ones (not sure specifically
of 9.0) were almost all plastic. I thought they were great and had no problems (a lot lighter too). Last year at Interbike I asked SRAM why they went away from plastic, after all they started as a plastics company. First response was increased reliability and accuracy. That said, your problem is much more likely to be related to cables and housing. Usually, the more direct routing (and perhaps increased cable travel) keeps shifting accurate for a long time without maintenance versus Shimano. That would be the first thing I would look at as your description of having to nudge the shifter fits right in with a bit of excess friction. I'm not a cable lube guy, but if I was, I wouldn't do it in your riding conditions. If you do, that could be the problem. After that, derailleur hanger alignment as already mentioned. Then bent derailleur. Only then would I think about the shifter. |
#4
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Repair Sram twist shifter?
On 2007-09-10, Dave wrote:
I have Sram 9.0 twist shifters and am having trouble with the rear shifter. The shifter seems like it is not snapping to the center of the shift detent, so on certain gears I have to nudge it slightly to prevent noise and/or skipping. So two questions: One, what's the expected service life of these shifters? I'd say I have maybe 400 hours use on them in dry dusty conditions. I'm not sure about the 9.0 shifters, but I had some cheaper ones wear out after a couple of thousand miles with the same symptoms. On that model the detents and the molding that held the spring could both wear over time. The 9.0 design is somewhat different but it could run into the same kind of problems if the internals are made of plastic. Two, anything I can do to service the innards? The first thing I'd do is replace your cables and housings. Excessive cable friction will cause the same symptom. If that doesn't work, open it up following the grip replacement procedu http://www.sram.com/_media/techdocs/SL_X_9SL_9_7_Ro_At_Ins02_02.PDF If you don't see anything obviously wrong (excessive wear, broken or disconnected coil spring, etc), you *might* try lubricating the interface between the fixed and rotating parts. I'm not sure what lube would be safe for that plastic though, so I'd exhaust all other options first. I have never worked on 9.0 twist shifters, so take this with a grain of salt. I'm going off of my experience with another model plus the drawings in the manual. |
#5
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Repair Sram twist shifter?
Dave wrote:
I have Sram 9.0 twist shifters and am having trouble with the rear shifter. The shifter seems like it is not snapping to the center of the shift detent, so on certain gears I have to nudge it slightly to prevent noise and/or skipping. So two questions: One, what's the expected service life of these shifters? I'd say I have maybe 400 hours use on them in dry dusty conditions. Two, anything I can do to service the innards? Investigate control wires/casing first, especially f there are any plastic ferrules in the system. We like skinny smooth wires running in 5.0 casing with 5.0 metal ferrules. Then look at chain wear and derailleur tab alignment, more likely than shifter wear. SRAM suggests their own non-petroleum-based lube inside the shifter. -- Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971 |
#6
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Repair Sram twist shifter?
On Sep 10, 8:13 pm, A Muzi wrote:
Dave wrote: I have Sram 9.0 twist shifters and am having trouble with the rear shifter. The shifter seems like it is not snapping to the center of the shift detent, so on certain gears I have to nudge it slightly to prevent noise and/or skipping. So two questions: One, what's the expected service life of these shifters? I'd say I have maybe 400 hours use on them in dry dusty conditions. Two, anything I can do to service the innards? Investigate control wires/casing first, especially f there are any plastic ferrules in the system. We like skinny smooth wires running in 5.0 casing with 5.0 metal ferrules. Then look at chain wear and derailleur tab alignment, more likely than shifter wear. SRAM suggests their own non-petroleum-based lube inside the shifter. -- Andrew Muziwww.yellowjersey.org Open every day since 1 April, 1971 Thanks all for the good suggestions. I replaced the cable, housing, and aligned the der tab (which was slightly off) all at once so I don't know what exactly fixed the problem, but its fixed. One interesting discovery...I had a difficult time installing the new cable in the shifter and had to disassemble it. I discovered burrs in the plastic all along the path where the cable bends to exit the shifter which were jamming the new cable. Turns out older SRAM twist shifters like mine need 1.1 mm cables, not the 1.2 mm shimano standard. I had been using 1.2 all along and I think this is what caused the burrs. |
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