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Old 04-16-12, 08:26 PM   #1
Mtbnomore
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Campy Athena chainring moving side to side under load

Okay, so let me start by mentioning a few things:

- The frame is an All-City Mr. Pink frameset with PF30 bottom bracket (it's steel).
- I equipped the bike with a Campy Athena groupset (Power Torque crank), and installed Power Torque PF30 cups with a headset press.
- The crankset Power Torque bolt (14mm, what a MONSTER) is plenty tight.
- I checked the chainring bolts, and they're all tight too.

Now, the problem I'm having is, when I'm climbing, pedaling at a high cadence, or really just pedaling in general, I can see the chainring moving 2-3mm left to right with each pedal stroke. I can see this if I look straight down through the front derailleur while I'm riding. After reading this thread: http://www.bikeforums.net/showthread...bottom+bracket , I am thinking of using Loc-tite on the cups. Will that get rid of the lateral movement though? Or should I maybe try getting adapters and a thread-in bottom bracket? Is the problem that it's a steel frame?

Any ideas would be great.
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Old 04-16-12, 08:50 PM   #2
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1st thing... there is an adapter for press fit 30 (PF30) and power torque??? just asking because i never seen that one. And if you are using something like a BB30 adapter that shoudlnt work too good eventho they share the 30 mm bb shell. The issue is that PF30 BB the outer shell is 46 mm i believe and the BB30 is 42... probably the play u see is coming from that tiny difference.

No idea if PF has kinda a set of cups with threads on them to thread the PT cups, Sorry i cant help you more because I havent move to BB30 or any oversize BB on any of my bikes yet, so i have not get into the standards more deeply.

Good luck.

ps: forgot this... once in place that shouldn't move that makes me think that maybe you got the wrong cups??, anyway I would add an extra wavy washer just in case, the other thing, did you measured the BB shell?? maybe is not 68 but less?? The cups you need are IC11-PT46 just in case.

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Old 04-16-12, 08:58 PM   #3
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Back in the day a few MMs of flex was the norm. Today it's reason to doubt the reason to get up in the morning.

I also don't try to follow all the possible combos of Bb standards and the resultant adapters needed to mix such. But if you have the correct set up then try lock tight on all. Then if there still is flex you might try out for the Olympic team, or learn to pedal a smooth circle. Andy.
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Old 04-16-12, 09:01 PM   #4
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You're right. I keep confusing the two (PF30 and BB30) when it comes to those adapters.

I checked the spacing, and it is 68. Thanks.
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Old 04-16-12, 09:13 PM   #5
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Ahhh, sounds like a bent chainring..
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Old 04-16-12, 09:19 PM   #6
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When it's in the repair stand though, there is no movement at all. Could a bent ring still be the case?

@Andrew: I typically wouldn't mind the movement, but it makes for FD/chain rubbing in a variety of gears beyond just when I'm cross-chaining.
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Old 04-16-12, 09:43 PM   #7
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Quote:
Originally Posted by Mtbnomore View Post
When it's in the repair stand though, there is no movement at all. Could a bent ring still be the case?
That information would have been helpful. I have read that improper installation can cause some lateral movement. Here is a thread discussion one person's fix and others that believe any problems are installation errors. http://forums.roadbikereview.com/cam...ue-189836.html

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