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Old 05-14-08, 07:29 AM   #1
salzman18
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Gearing question...chain sound

Hi, first time poster. I just had a custom bike built and everyone pushed me to get campy record components. Previous to this I had Shimano Ultegra. After putting some miles on the new bike, I have a few questions:

--My Campy is 50:34 up front and 12-25 in back. I am a bit surprised that when I am in my smaller ring up front, I begin to hear some chain sound when I am 3 gears from the smallest in back. I can trim the sound out using the left paddle while in the 3rd from smallest but as I go to the second and finally smallest, I can't. By the way, I have a Wipperman chain. Now I know what you are all going to say...you aren't supposed to cross chain lilke that anyway, but there are times when you have to for a few minutes and my lowly Ultegra doesn't make a sound in any gear. Is this normal? If so, it's a bit of a shame that I have almost 3 gears that can't be used. What then makes Campy so great? I love the ergonomics of the hoods but from a pure shifting point of view, I like the Shimano better.

--Also, the Shimano has 50/36 up front and 12-28 in back. With the Campy setup my ultimate lowest gear is not as low as with the Shimano. There is also not as much overlap between the high range (big ring up front) and low range as with the Shimano. In other words with the Shimano, the highest gear in the low range is higher and the lowest gear in the high range is lower than with the Campy. I like this becasue in practice I could be going along at 18 mph in the large ring up front and see a hill coming up...I can then switch down to the small ring up front in anticipation of the hill and still not "over rev". Then, I have 10 good gears to use as I go up the hill. With the Campy, I can't do this becasue when I switch from the big ring to the small ring the gearing is too low for the speed and I end up "over revving". So with the Campy, I have to shift from big rignt to small ring somewhere in the middle of casette. I hope that some of this is making sense to someone. I guess my question is...they must know what they're doing at Campy so what is the thinking behind the gearing? Am I missing something?

It seems that with the Shimano, I get more usable gears and a wider overall range of gears.
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Old 05-14-08, 07:52 AM   #2
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I lost my concentration on the 3rd paragraph.... but as for your 2nd, I get the same thing you are getting with your Campy on my Ultegra components. Once I'm on the 3rd highest gear in the back I start to get some chain rub on the front derailleur, I can do a slight "trim" adjustment and it's fine, but in the 2nd highest and 1st highest gear it will always rub. I don't have any issues with it, I'm used to it and I don't cross chain.

Was your Ultegra 10 spd or 9 spd?
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Old 05-14-08, 08:03 AM   #3
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Thanks. The ultegra was 10 in back.
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Old 05-14-08, 08:54 AM   #4
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Using the big-big and small-small combos is called cross-chaining, and is generally frowned upon as it puts more stress (and wear) on your drivetrain components due to the extreme angle you are forcing the chain to take. Furthermore, modern road bikes, especially higher performance frames, have shorter chainstays. This makes the angles even more extreme and is usually the cause of the chain rubbing while in the 2nd smallest cog. Unless you are riding a longer wheelbase touring frame, there isn't much you can do about it. Having 20 possible combinations doesn't give you 20 usable or even useful comnbinations.
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Old 05-14-08, 09:07 AM   #5
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If the chain is rubbing on the front derailleur cage, you can trim it out with the brifter. If the chain is rubbing on the inside of the big chainring, there isn't much you can do except use a longer bottom bracket.

Compact cranks, with their big difference in chainring diameters, are more prone to having the chain rub on the big ring when in the small ring.

BTW, my experience with Campy is that the front shifting is pretty reliable, even under a considerable load, so very early shifting to the small ring may not be essential.
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Old 05-14-08, 09:14 AM   #6
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Thank you to all. I appreciate all of the input. You are right that on the smalles ring up front and smalles cog in back the chain itself is actually rubbing the outer ring. I think this didn't happen on the Shimano becasue the inner ring was a bit larger. I also get the feeling that the Wipperman chain is not as flexible side to side as the Shimano.

The real question is...whey does everyone go for these compact gears?
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