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Old 04-20-14, 12:53 PM   #1
nesteel 
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Shimano Sora front double shifting problem

Okay, general rundown: Bike is an '86 Centurion Lemans RS. Recently put on the following components: Sora 2x9 brifters, RD, FD (double), Weinmann XP27 wheels w/9 speed SunRace cassette. Bike was already equipped with a Shimano FC-2300 crank. I made an aluminum shim to adapt the 31.8 dia. FD to my 28.6 seat tube. It act's like the shifter for the front doesn't have enough pull. It will shift from the small chainring to the large chainring, and vice versa on the stand, but not when I'm riding. Any theories?
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Old 04-20-14, 01:11 PM   #2
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Could be you need to set both trim and outer limit to allow a more aggressive shift action. Or it could be that you have too much pedal pressure during the shift. Older chainrings don't have ramps and pick-up pins like modern ones do, so a bit more rider help through the shift is called for.
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Old 04-20-14, 05:54 PM   #3
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Well, after two days, and countless test rides, I gave up on ever getting the this particular Sora double FD to work. No amount of tweaking, adjusting the limits, or anything else for that matter, would allow it to shift to the large chain ring while riding.
Out of curiosity, I threw an older RSX triple FD on it, adjusted it properly, and SHAZAM, works beautifully. I may try a Sora triple FD at some point, but for now I'll just enjoy riding it, and having full access to all 18 gears (although I rode 23 miles this morning using only the bottom 9).
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Old 04-20-14, 06:22 PM   #4
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Sounds like you made a good decision. I have also had several battles with Sora front shifters and brifters and they can be difficult. They seem much less forgiving when it comes to overal setup than other setups. My quess would be the BB on your bike is couple mm's off ideal spec length wise which is OK on a double with most shifters but not with Sora's. Using a nicer triple FD with slightly more capacity is a perfectly OK way to get around this.
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Old 04-25-14, 07:36 PM   #5
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Update: Finally got the Sora FD to work. The other two FD's I tried were okay/not ideal, and I decided to dig a little deeper. Upon checking the chainline, and realizing the bottom bracket spindle was too wide (I bought the bike as a partially assembled from a small independent bike "shop". NO MATTER WHAT, ALWAYS CHECK THE BASICS), I bit the bullet and went to the bike shop I prefer. Picked up a modern sealed bearing BB in 110 width, assembled it, put the Sora FD back on, adjusted it, and life is good. I've got about 20 miles on it, and it shifts SO much better.
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Old 04-25-14, 07:55 PM   #6
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Does zukahn get a prize?
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