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Convert downtube to STI

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Old 09-25-06, 02:56 PM
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Convert downtube to STI

Hi all,

Is is possible to convert a shimano seven speed downtube shifters to STI? I know the older STI shifters aren't that good. Can the 9 speed shifter be made to work with a seven speed cassette?
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Old 09-25-06, 02:57 PM
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7 speed Sora STI would be a great choice.
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Old 09-25-06, 05:20 PM
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Older Shimano 7-speed RSX were good and functional shiftrer with decent reliability. Sora shifters are a less convenient design but work ok.

9-speed shifters won't work with a 7-speed cassette since the cog spacing is different. One work-around is to install 8 cogs of a 9-speed cassette on a 7-speed freehub and lock out one click with the limit screws. That gives you compatible 9-speed spacing, lets you use your 7-speed hubs and adds one more cog to your choices.
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Old 09-25-06, 05:45 PM
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Originally Posted by shakadude
Hi all,

Is is possible to convert a shimano seven speed downtube shifters to STI? I know the older STI shifters aren't that good. Can the 9 speed shifter be made to work with a seven speed cassette?
Yes, they have sora 7 speed STI still available everywhere.
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Old 09-25-06, 08:39 PM
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See this page

In practice, since 7 speed and 8 speed spacing are very similar, you could use a 9-speed shifter with your 7-speed cassette if you install the cable according to the alternate cable routing (see link above).

Or build your own 8-speeds-out-of-9 cassette. (see this)
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Old 09-26-06, 05:44 AM
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Wouldn't it be alot easier to just put a nine speed wheel on the back? If your riding a seven speed I'm guessing you have 126 rear spacing and spreading to 130 would not be that hard.
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Old 09-26-06, 06:29 AM
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if the bike is steel, this is true. Unfortunately, aluminum will weaken if spread even that much. I say pick up a shimano 8-speed cassette and older 8-speed shifters. That's what I plan to do on my commuter once I wear out the wheels.
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