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Discussion Starter · #1 ·
Today, while riding as usual, my Chorus 11 crank set suddenly got stiff and wouldn't turn an inch!

I realised that something was definately wrong with it. Eventually, using a little of force, it got moving again but the tightness came and went and luckily i arrived home within 15 minutes since the problem started.

While i rode, i realised that when the crank set was rather tight to pedal, the chain set was sort of swaying to and fro by a few milimetres.... when the crank set was loose and felt normal to ride on, the chain set rotated as usual.

Immediately upon arriving home, i undid my Chorus 11 crankset and I think i found the cause of the problem. The spacer that fits between the left crank arm and the bottom bracket cups was bent in 4 areas, which sort of explained the strange rotation of the chain rings when the crank set was so tight to ride on.

I looked around my apartment but could not find a similar spacer to replace it with. I remounted the left crank arm without this damaged spacer.

Do you think the crank set will develop problems later?

Have any of you had this problem before? How did you deal with it?:idea:
 

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ishmaelmuscat said:
Today, while riding as usual, my Chorus 11 crank set suddenly got stiff and wouldn't turn an inch!

I realised that something was definately wrong with it.
Wow, aren't you the observant guy! :rolleyes: Sorry, couldn't resist.

ishmaelmuscat said:
Immediately upon arriving home, i undid my Chorus 11 crankset and I think i found the cause of the problem. The spacer that fits between the left crank arm and the bottom bracket cups was bent in 4 areas, which sort of explained the strange rotation of the chain rings when the crank set was so tight to ride on.
:mad2: That's not a spacer, it is called a wave washer. It's supposed to look this way, and it is essential for the function of this crankset.

ishmaelmuscat said:
I looked around my apartment but could not find a similar spacer to replace it with. I remounted the left crank arm without this damaged spacer.

Do you think the crank set will develop problems later?
You need this part, and your crankset has a serious problem already. Hard to tell from your description. Take the bike to a competent bike shop.
 

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thoughts...

That's a wave washer not a spacer and the shape of it is normal. Most likely, either one of the BB cups has unscrewed a bit, or one of the bearings is totally trashed. If the center fixing bolt was loose, it would not get harder to turn.

Take the whole thing apart, put new bearings in and be sure the cups are installed properly, with greased threads torqued to 35Nm.
 

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Matnlely Dregaend
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Bianchi-Campagnolo
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My understandig is that the drive side retaining clip's only function is to keep the right crank arm in place when the left crank arm is not mounted.
 

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no....

kbwh said:
My understandig is that the drive side retaining clip's only function is to keep the right crank arm in place when the left crank arm is not mounted.
As a mechanical engineer, I can assure you that the clip performs a vital function. If it's not in place, then forces toward the right could move the entire crank toward the right, squash the wave washer and unload the right side bearing.

The other amusing idea is that it's there as a safety feature, so the right crank arm won't fall off. I guess it's OK if the left side falls off.
 

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Bianchi-Campagnolo
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I need a drawing to comprehend what you're saying in you first paragraph, C-40. Shall google.
 

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here...

kbwh said:
I need a drawing to comprehend what you're saying in you first paragraph, C-40. Shall google.


The wave washer sits between the lef bearing and the cup. It pushes to the left, on the left side bearing and transmits a force that holds the right bearing against the face of the cup. If the clip was not there, nothing would keep the crank from moving side to side, except the wave washer and it squashed completely with a little over 60 pounds of force.
 

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Matnlely Dregaend
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well...

orange_julius said:
Despite dire warnings on the installation manual, it is really astonishing how many people leave out the clip and/or the wave washer.
If fools leave either part out, the crank will not work for long. You have to be real idiot to ignore the instructions, then whine because the bearings crapped out quickly. Each part has a definite function.
 

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I'm a smart guy. The instructions did not tell me to remove the clip after installation, so I left it in.
Thanks for drawings and links, guys. I've done some investigation myself as well. And I think I got it.
 

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C-40 said:
If fools leave either part out, the crank will not work for long. You have to be real idiot to ignore the instructions, then whine because the bearings crapped out quickly. Each part has a definite function.
My favorite "trick" of the illuminati is to insert the center bolt from the non-drive side... :mad2:
 

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C-40 said:
As a mechanical engineer, I can assure you that the clip performs a vital function. If it's not in place, then forces toward the right could move the entire crank toward the right, squash the wave washer and unload the right side bearing.
While you are certainly correct on this, I have always wondered how big of a deal it might be to not have the clip in place. After all, it does take quite a bit of force to overcome the pressure from the spring washer, and I am not sure under what circumstances, if ever, you would see such large side forces. But, of course, better safe than sorry, and in any case the Campy instructions are gospel, most of the time, anyway... :D
 

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Discussion Starter · #15 ·
No wonder...

Pirx said:
Wow, aren't you the observant guy! :rolleyes: Sorry, couldn't resist.



:mad2: That's not a spacer, it is called a wave washer. It's supposed to look this way, and it is essential for the function of this crankset.



You need this part, and your crankset has a serious problem already. Hard to tell from your description. Take the bike to a competent bike shop.
No wonder i was baffled how it ended up in such a state.. i never really noticed it before.:mad2:
 

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Discussion Starter · #16 ·
Thanks

C-40 said:
That's a wave washer not a spacer and the shape of it is normal. Most likely, either one of the BB cups has unscrewed a bit, or one of the bearings is totally trashed. If the center fixing bolt was loose, it would not get harder to turn.

Take the whole thing apart, put new bearings in and be sure the cups are installed properly, with greased threads torqued to 35Nm.
Thanks! Going to a bike shop now to have the cups analyzed and re-installed.
 

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Discussion Starter · #17 ·
Still there

DrSmile said:
My guess is the retaining clip on the drive-train side has gone amiss... this would push the left crank towards the frame every time you applied power.

It looks like this:



$5 from

https://www.universalcycles.com/shopping/product_details.php?id=16125&category=2634
I know about the function of this retaining clip. It was always there and still is. Since you mentioned it, should the clip be place on the cups after crankset installation tightening or before?
 

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ishmaelmuscat said:
I know about the function of this retaining clip. It was always there and still is. Since you mentioned it, should the clip be place on the cups after crankset installation tightening or before?
Well, the instructions say that it should be put in place immediately after you place the drive-side crank onto the cup/BB ...
 
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