Derailer travel
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Derailer travel
I'm upgrading an older road bike that came with a Shimano 600 non-indexed derailer. I've installed a 105 8 speed STI shifter and an 8 speed cassette. The problem is that some shifts are correct, while others skip a cog and go to the next. I've spoken to several bike mechanics and they said my derailer should work fine since the indexing is done at the shifter. Here's what I found; The cable travels a toltal of about 7/8" out from the shifter to go from 1st to 8th gear. The derailer, however, requires only about 1/2" to 5/8" cable travel to move from the smallest to the largest cog. This results in the derailer going the full range of gears before the shifter has had a chance to advance it's full travel and so, it seems that maybe the ratio of derailer cable travel to derailer movment is not what it should be for this shifter setup. Bottom line; Do I need a new derailer? Are there varying ratios for different derailers?
Thanks,
Rich
Thanks,
Rich
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Originally posted by Coaster
I'm upgrading an older road bike that came with a Shimano 600 non-indexed derailer. I've installed a 105 8 speed STI shifter and an 8 speed cassette. I've spoken to several bike mechanics and they said my derailer should work fine since the indexing is done at the shifter. Do I need a new derailer? Are there varying ratios for different derailers?
Rich
I'm upgrading an older road bike that came with a Shimano 600 non-indexed derailer. I've installed a 105 8 speed STI shifter and an 8 speed cassette. I've spoken to several bike mechanics and they said my derailer should work fine since the indexing is done at the shifter. Do I need a new derailer? Are there varying ratios for different derailers?
Rich
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If it's jumping from one gear to the next, I'd be wondering about the condition of the cogs and/or chain. Are both of these components used? If so, they are probably worn out, and need replacement.
Otherwise, I'd keep adjusting the derailleur. Perhaps the derailleur is not compatible with the shifters-this can happen when you mix-and-match old and new components. Chances are, a 6-cog derailleur is not compatible with newer stuff.
Otherwise, I'd keep adjusting the derailleur. Perhaps the derailleur is not compatible with the shifters-this can happen when you mix-and-match old and new components. Chances are, a 6-cog derailleur is not compatible with newer stuff.
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Originally posted by D*Alex
Chances are, a 6-cog derailleur is not compatible with newer stuff.
Chances are, a 6-cog derailleur is not compatible with newer stuff.
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Well, that makes sense to me. The cassette and chain are new, the only thing left is the derailer. The indexed type probably has a longer cable travel (and a slower action) than the non-indexed type.
Thanks,
Rich
Thanks,
Rich