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Old 04-02-12, 03:40 PM   #1
equinoxx
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sram rival / bent rear derailleur??

The rear shifting in my bike has always been very abrupt, to the point there is a twang that reverberates through the (titanium) frame every time I upshift to a smaller rear cog. From viewing/reading tutorials, I understand the jockey wheels in the rear derailleur should typically line up with whatever rear cog is selected.

On my bike, the rear derailleur seems a bit skewed. Not sure if this is causing the abrupt shifting or whether it is an issue at all. Would appreciate any input. For what it is worth, the rear derailleur shifts through all the gears up and down, its just not very smooth on the upshifts.

Pictures:
[on small ring gear up front]




[on big ring up front]


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Old 04-02-12, 05:00 PM   #2
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Kinda hard to tell from the photos but, the 2nd from last looks like the derailleur hanger might be bent forward at 3 o'clock. A derailleur alignment gauge will tell you for sure but not everyone owns one of those. Id try a new hanger.
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Old 04-02-12, 06:53 PM   #3
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Obviously, I can't be sure from a photo, but I strongly suspect that all is fine. I base that on the fact that shifting is crisp in both directions, which is about as good as it gets. Your noisy upshifts is characteristic of Sram index systems which are said to shift even more positively under power than Shimano, which was always the gold standard.

There's no touch so when the escapement in the lever lets it out one click it does so quickly and the RD responds as fast as the cable allows. All I can suggest is that you try to lighten the pedal load a bit during the shift, and power up after it engages the new sprocket.

You might double check the hanger alignment, but don't spend dough for a replacement since newly installed hangers need to be straightened also. But I suspect that no matter what you do or spend, hardware changes won't help. Ease up on the pedals and get used to the Sram system. Anyway, it could be worse, at least you don't have one of those freehubs that sound like chainsaws.
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Old 04-03-12, 02:50 PM   #4
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Thank you both for your responses. A replacement hanger is pretty cheap. I'll give that a shot and see if it makes a difference. If not, I will get used to the shifting eventually
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Old 04-03-12, 03:07 PM   #5
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Then take the bike to a Bike Shop, and their Alignment gage will bring it into the needed
Perpendicular to the axis, parallel to the centerline plane.

even a new dropout wont necessarily bring it into the kind of precision,
a little tweaking the derailleur hanger alignment gage will.
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