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Old 08-07-10, 07:50 PM   #1
psychling78
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Shimano Sora STI 3300 7 speed shifters used for 8 speed rear?

A guy on a Well-Known Auction Site is attempting to sell a set of aforementioned shifters and claims that they will work with an 8-speed cassette. Seems odd to me. Ideas?
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Old 08-07-10, 08:16 PM   #2
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They won't index properly. Period. Don't buy into a problem.
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Old 08-07-10, 08:35 PM   #3
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7-speed and 8-speed cassette spacing is a "hair" off. Some people claim to have mixed and matched 7-speed and 8-speed parts with satisfactory results but I've personally never been pleased when I've tried it.

Bottom line, I might give it a try if I already owned all of the respective components but, if I were buying components, I'd hold out for matching parts.
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Old 08-07-10, 08:47 PM   #4
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Even if the click-stop spacing were right, the 7-speed shifter simply doesn't have enough click stops to put the chain on all eight of your cogs. By definition, it won't completely work.
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Old 08-08-10, 12:22 AM   #5
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If you need the brifters and they are cheap enough, I'd vote to get them and buy a 7-speed cassette. Even if you got 8-spd brifters (or could make the 7-speed work properly somehow) the one extra gear isn't going to make or break the quality of your ride.

I say, $20 brifters with a 7spd is way better than $150 brifters with 8 speed.
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Old 08-08-10, 03:02 AM   #6
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It'd be a good setup for an old frame you didn't want to respace... but only if you ditched a cog and used a narrower cassette body (with an OCR, I reckon you could have a rock-solid 7spd wheel despite 120mm OLD).

I suspect 7spd indexing across 8spd spacing could be set up to shift rather well, albeit with a fairly narrow window of proper adjustment. But anyway, increasing your spacing is easy - you can just cut washers from plastic sheet.
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Old 08-08-10, 01:38 PM   #7
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Thanks, all. My suspicions are confirmed. I'm poor but not yet so poor to give up my 8 for a 7. The STI is just something I'd like to try someday. Still on downshifters -- just raced for the first time in a while yesterday and felt a bit at a loss.... but then it was a cat 4/5 crit, so what can you do? Thanks again.
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