Headtube bearings confusion - please advice

Discuss light weight issues concerning road bikes & parts.
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PixelGarden
Posts: 3
Joined: Fri Feb 17, 2017 12:24 am

by PixelGarden

Issue was solved :D
Last edited by PixelGarden on Sat Mar 03, 2018 7:24 pm, edited 3 times in total.

joejack951
Posts: 345
Joined: Fri Feb 18, 2005 6:50 pm
Location: Wilmington, DE

by joejack951

Integrated headset cartridge bearings are rarely, if ever, pressed into the frame. Instead, they are centered in the frame by a conical surface molded into the frame itself (or cut into a metal race inserted in the frame) and a matching surface cut into the bearing. If the dimensions of those cuts does not agree with the frame dimensions, you can have a headset that is either too tall or, worse, too short when assembled. Another possible cause of a too tall headset stack would be an improperly/not fully seated crown race. Someone could also have added shims when they were not needed.

Regardless, it looks like your mechanic fixed the issue. The grease will keep the bearings from creaking.

by Weenie


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Calnago
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Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

It certainly sounds to me like your mechanic doesn't have a clue, and worse, he sent it back to you completely messed up. Those are pressed in bearings/cups (combined). The bearings are not slip fit, but pressed into the cups themselves. There is supposed to be a gap between the crown of the fork and the bottom cup. Removing the fork should not result in a bunch of loose bearings falling out. And be very careful about using a standard headset removal tool on a C60. It is extremely easy to catch the lip of the bonded in alloy sleeve (versus the lip of the bearing cup). You need to ask them exactly what they did first of all, but whatever it is they did, I really don't think (from what you said), that they had a clue what they were doing. No idea. But at this point, they owe you a completely new Colnago Headset (those bearings and cups are from Acros, and a pretty specific size). Did you buy the bike there? I can't imagine it's a Colnago dealer, if that's what they did to your headset. Also, ask them why they thought the beraing was a millilmeter too big. This I want to hear. It they say because it was "stuck" in the cup, then scream bloody murder and inform them that it's supposed to be "stuck" in the cup. It's a pressfit cup and bearing assembly. The cup and bearing get pressed into the headtube as a unit. The bearings themselves were pressed in to the cups at the Acros factory. Aaachh. Hate to hear LBS mechanic stories like this.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

joejack951
Posts: 345
Joined: Fri Feb 18, 2005 6:50 pm
Location: Wilmington, DE

by joejack951

Shows what I know about Colnagos!

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showdown
Posts: 232
Joined: Fri Sep 17, 2010 4:48 pm

by showdown

Like Cal said, there's supposed to be a 1mm gap between the bottom of the headtube and he top of the fork. This is by design. The headset bearings are not supposed to fall out of the headtube at all. They are pressed in and while not permanent are snug. My bike came directly from Colnago USA where I watched them build the bike. They used the same Loctite 640 on the headset and bottom bracket.

Your mechanic messed up big time.

Image

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Calnago
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by Calnago

@Showdown: The headset cups/bearings are installed at the factory. Are you saying you actually witnessed them pressing in the headset at Colnago USA? It's certainly possible I suppose that they may have shipped a frame without a headset already pressed in but I can't imagine why. Was yours some sort of warranty replacement frame or something, where they may have just used the headset from your old frame? I'm curious.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

PixelGarden
Posts: 3
Joined: Fri Feb 17, 2017 12:24 am

by PixelGarden

Thanks for your help and comments, really appreciate it :thumbup:
Last edited by PixelGarden on Thu Nov 16, 2017 11:10 pm, edited 1 time in total.

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showdown
Posts: 232
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by showdown

@Cal

Yeah. We're a Colnago-sponsored team and and have a special relationship with them being in Chicago; we like to loiter at their offices and ogle all the cool Colnago stuff they have there.... I got the C60 TXOR (gray and neon orange) before it was technically available to the world so it came to the USA without the headset installed. I suspect it was just an oversight or something... It really wasn't a big deal to install and took all of 20 seconds.

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JKolmo
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Joined: Sat Feb 10, 2007 2:00 pm

by JKolmo

joejack951 wrote:Shows what I know about Colnagos!


He he, in addition: the C60 doesn't have a crown race.

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Calnago
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Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

Actually, the first C60's did in fact come with a split crown race, but because it is of the split variety, there is little chance of it not begin seated correctly under any type of compression at all. So, there's actually at least a couple versions of headsets that have been used in the C60 already. But I think very soon after they just did away with that altogether and incorporate the crown race directly into the fork molding, like many other manufacturers are doing now. I'm a bit worried for our OP, since while pressing in a new headset is quite easy with the proper tools, removing the cups, well... the lower cup at least, is not so straightforward due to the fact that the alloy sleeve the cup is pressed into is about 10mm deep while the bearing cup is about 9mm, leaving only 1mm of exposed alloy that the removal tool must spring and expand up against. I really scratched my head over this for a long time since despite having 3 different sized removal tools, the only one that would work had such a spring effect, and wide opening, that I could not get it to properly seat on just the bearing cup surface. It would instantly be seated on the edge of the alloy sleeve (part of the frame), and banging on that under the impression you were banging on the bearing cup would not be good. So, to OP... if you head off to the shop soon, keep that in mind. When I get around to it today I'll add a bit to this thread.
The thing about these headsets is that they should rarely if ever need servicing, so I doubt very many shop mechanics have actually removed one for any reason.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

PixelGarden
Posts: 3
Joined: Fri Feb 17, 2017 12:24 am

by PixelGarden

Thanks for all your input, it helps a lot!
Last edited by PixelGarden on Thu Nov 16, 2017 11:10 pm, edited 1 time in total.

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Calnago
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by Calnago

You did the right thing in not letting him touch it further. Take it somewhere else where they might actually try to understand how it's supposed to be before they start wrecking it.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

AJS914
Posts: 1949
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

Dang, this is why I like to work on my own bikes. I can't believe this mechanic just took the initiative to do something that wasn't requested.

I need to find a shop to face my new-to-me C40 because even though it was previously built up, it was never done. I've kind of dreading finding a good mechanic since I'm in a new city.

by Weenie


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