Cannondale lightweight compression top cap problems

Discuss light weight issues concerning road bikes & parts.
thisisatest
Shop Owner
Posts: 1980
Joined: Sat Jun 13, 2009 4:02 am
Location: NoVA/DC

by thisisatest

take the lightweight compression plug apart. grease the threads of the small aluminum screw, the threads of the main "body" of the assembly, and the underside of the top cap itself where it would rest on the stem.
let me know how it goes.
ive installed many of these assemblies and have not heard any one of them creak.

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Miller
Posts: 1275
Joined: Thu Sep 21, 2006 8:54 pm
Location: Reading, UK

by Miller

OwenJames wrote: Nothing was said about installing it upside-down, tightening it to 1,000,000nm by mistake, sawing it in half to save even more weight, or putting it in that machine Jeff Goldblum uses to teleport himself in the The Fly...


Wow. Love it!

centhar
Posts: 22
Joined: Mon Feb 27, 2012 11:59 pm

by centhar

take the lightweight compression plug apart. grease the threads of the small aluminum screw, the threads of the main "body" of the assembly, and the underside of the top cap itself where it would rest on the stem.


^^This. :thumbup:

OwenJames
Posts: 166
Joined: Mon Apr 11, 2011 3:16 pm

by OwenJames

Right.

Update on my headset woe.

Despite swapping out the new compression plug for the older heavier one, I was still having the problems, so decided to get to the bottom of what was happening in a bid to fix it.

So, here is exactly what I found...

-I took the headset apart, took the forks out and had a good look around. The top and bottom shoulders where the bearings sit in the headtube seem fine. No cracks, nothing split open, no odd patches of wear, etc.
-Bearings seem fine when turning them in my hands. Under compression I can not tell, of course as they are hidden in the frame during this state.
-The stem seems fine, nothing scratched or broken on the part that clamps the steerer. Bolts are fine.
-The ring that slides onto the top bearing as part of the compression system is fine.
-The bearings sit in the top and bottom of the head tube fine. They do move slightly but this is no different to any other frame I have played with.

So, everything, I think, is OK.

BUT...

When assembled, which I do correctly, I am still having a problem.

When I push hard 'down and left' or 'down and right' on the bars with my hands on the drops, the top bearing / compression ring / top bearing cover, etc, seem to shift sideways away from the side I am pushing down on. When it shifts, there is a knocking noise as something hits something else. When the top part of the headset shifts, the side that it has shifted to has an ever so slightly raised bearing cover, with the other side of the bearing cover pushed flush with the edge of the headtube.

I have tried compressing the headset extra tight with the compression plug, but no matter how tight it goes, the left to right shifting still happens.

I did not apply carbon assembly paste where the stem clamps onto the carbon steerer, which I am wondering might be an issue?

Anybody else had similar, as this is driving me mad and I feel I have tried everything!
Last edited by OwenJames on Tue Sep 10, 2013 11:50 am, edited 1 time in total.

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bikerjulio
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Joined: Fri Dec 11, 2009 10:38 pm
Location: Welland, Ontario

by bikerjulio

I have tried compressing the headset extra tight with the compression plug, but no matter how tight it goes, the left to right shifting still happens.


From this description it sounds that the top cap is bottoming out before the bearings are compressed. There can be a couple of reasons:

Compression plug not far enough into the steerer (or not tight enough), and top cap is bottoming on it.

or

Insufficient spacers such that the top cap is bottoming out on the top of the steerer tube. (with the assembly compressed by hand pressure on the stem before tightening, there should be 2mm between the top of the stem and the top of the steerer tube).

Pictures of your setup might help. Don't try to ride the bike until this is resolved.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

OwenJames
Posts: 166
Joined: Mon Apr 11, 2011 3:16 pm

by OwenJames

Hi,

Thanks for the speedy response.

I have checked and I have adequate spacers. There is approximately 2mm of space as you describe. I have a 3mm

I have reseated both of the compression plugs I have several times to ensure they are not bottoming out and the problem remains. I have also checked the tightness of the inner part of the compression plugs, with both plugs. Again, no issues.

It really is very strange.

I have a SuperSix Evo, which is carbon; dumb question, but it is possible to ovalise a carbon headtube, like you can with metal?

OwenJames
Posts: 166
Joined: Mon Apr 11, 2011 3:16 pm

by OwenJames

Oh, and I have never crashed it, or done anything silly when riding it. I treat it extremely well.

Causidicus
Posts: 325
Joined: Tue Apr 17, 2012 11:20 am

by Causidicus

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Last edited by Causidicus on Tue Jun 17, 2014 10:51 pm, edited 1 time in total.

OwenJames
Posts: 166
Joined: Mon Apr 11, 2011 3:16 pm

by OwenJames

Causidicus wrote:
OwenJames wrote:When I push hard 'down and left' or 'down and right' on the bars with my hands on the drops, the top bearing / compression ring / top bearing cover, etc, seem to shift sideways away from the side I am pushing down on.

Sounds like a missing steerer conical bearing locator to me.


Hi.

What does that look like?

Is that the small silver ring with angled edges that slides down the steerer tube and sits into the inside race of the top bearing, before the black Cannondale top bearing cover goes on?

This is a link to the complete headset on CannondaleExperts; are you referring to the part at the bottom of the picture in the middle?

http://www.cannondaleexperts.com/Cannon ... p_356.html

If so, I have installed that.

Causidicus
Posts: 325
Joined: Tue Apr 17, 2012 11:20 am

by Causidicus

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Last edited by Causidicus on Tue Jun 17, 2014 10:50 pm, edited 1 time in total.

OwenJames
Posts: 166
Joined: Mon Apr 11, 2011 3:16 pm

by OwenJames

When you say the bearings are loose in the frame, how loose do you mean?

On the top and bottom of the headtube, the bearings drop in, but there is a tiny amount of movement on all sides. I assumed this was normal, and I seem to remember the exact same thing with my CAAD9. The bearings have an angled edge where the sit in the headtube on the top and bottom, on an angled shoulder, so I thought that once they were seated in the correct position, the small amount of play did not matter and was part of the design...

For anyone else who has taken a headset apart on an Evo, or any carbon frame for that matter, how tight are the bearing units to put in?

The fact that the bearings drop in to the top AND bottom and have some slight play (like way less than a mm) is telling me (I hope!) that it is supposed to be like that.

I suppose I should have mentioned that all this started when I switched from a Deda Zero100 stem to a Deda Superleggero stem... Could this be a case of the stem slipping a tiny bit on the carbon steerer and allowing play...?

Causidicus
Posts: 325
Joined: Tue Apr 17, 2012 11:20 am

by Causidicus

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Last edited by Causidicus on Tue Jun 17, 2014 10:49 pm, edited 1 time in total.

OwenJames
Posts: 166
Joined: Mon Apr 11, 2011 3:16 pm

by OwenJames

'Bingo' as in, you think think that both the top and bottom of my carbon headtube have flared at the same time? Is that even possible?

Causidicus
Posts: 325
Joined: Tue Apr 17, 2012 11:20 am

by Causidicus

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Last edited by Causidicus on Tue Jun 17, 2014 10:49 pm, edited 1 time in total.

OwenJames
Posts: 166
Joined: Mon Apr 11, 2011 3:16 pm

by OwenJames

Well, if they are the wrong size, then Cannondale put the wrong Cannondale SuperSix Evo headset in the Cannondale SuperSix Evo frameset they sold me.

When I say they are loose, I mean that they are not an interference fit, rather they drop into place without having to be forced, which also means they can be wiggled about slightly once in position. I honestly assumed this is the same for all integrated headsets... If anyone knows different, do say!

Anyway, I do really appreciate your input.

If we shift to an alternative reality where it is not the bearings or the headset, and all the parts are in place, is there anything else you could imagine it to be?

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