Headset Install Help...

Discuss light weight issues concerning road bikes & parts.

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boleiro
Posts: 18
Joined: Thu Sep 15, 2016 4:31 pm

by boleiro

just started a new build and already hit a snag... the lower bearing sits high on the crown race. Shouldn't the bearing cartridge sit flush on the crown race, not on the angled part? This is making the gap between the fork and frame really pronounced.

per the pics... anyone have any information that might help. Thanks!
crown race 2.jpg
crown race 1.jpg
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by Weenie


joejack951
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by joejack951

The bearing should only contact the crown race on the tapered inner section. If it contacted elsewhere first, the bearing would not be able to do its main functions (hold the steerer tube concentric to the headtube and allow it to rotate smoothly). However, as you’ve noted there is quite a large gap between the bearing and crown race.

Did those two parts come packaged together? If not, that’s the source of your issue for sure. As far as I can tell, there are no industry standards for the chamfers/angled cuts on the ID and OD of headset bearings, other than the angle of the cut. The depth can vary significantly between brands and aftermarket bearings are a total crapshoot.

You need to either figure out the specs of the bearing chamfer that match your crown race and find a compatible bearing or source a paired bearing and crown race. If you already did the latter and this is what you received, demand parts that fit properly. That gap is unacceptable. It should be 1mm max and closer to 0.5mm ideally.

boleiro
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by boleiro

thanks for the info... that confirms my thoughts. Yes, it's a new FSA headset, the crown race and bearing were packaged together. I'm going to go for a different headset.
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dannywin42
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by dannywin42

How big is the gap in the split in the crown race after you've installed it? Thinking aloud it might not be the race and bearing but rather the diameter of the fork shaft where the race is now sat. If it's a touch on the large side that could be causing the race to be over splayed and thus no longer fit inside the bearing ID properly and so you may have the same issue with another headset.

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joejack951
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by joejack951

dannywin42 wrote:
Tue Jan 07, 2020 8:49 am
How big is the gap in the split in the crown race after you've installed it? Thinking aloud it might not be the race and bearing but rather the diameter of the fork shaft where the race is now sat. If it's a touch on the large side that could be causing the race to be over splayed and thus no longer fit inside the bearing ID properly and so you may have the same issue with another headset.
Good point. I was assuming that the race was not split. If it is, that could definitely be the issue, too.

How does the race fit the bearing when not installed on the fork?

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Miller
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by Miller

When you offer up the fork to the frame, with the bearing installed, what does the gap look like then? Bearing in mind that for a full assessment you might need a proper fork install with the upper bearing in place and preload set.

boleiro
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by boleiro

***Duplicate Post***
Last edited by boleiro on Tue Jan 07, 2020 4:26 pm, edited 1 time in total.
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boleiro
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by boleiro

The crown race is NOT split... it went on easily with my trusty PVC tool. Unfortunately I don't remember how the bearing sat on the race before install... didn't pay too much attention to that. I have looked at a lot of pics online to see how it sits but can't find any pics besides the marketing pics that don't help much. But, I can say the bearing does seem to fit the crown race upper diameter perfectly sitting at the very top of the angled portion. I'm starting to think the lower bearing cartridge needs to be angled to allow it to sit more snug in the headube... hard to tell if the headtube has an angled area where the bearing sits in like the top does. I ordered another headset that matches the one I have now but it does have an angled lower bearding cartridge. As noted by Miller, I will try a full install with preload to see if this helps... and I'll try tomorrow with the angled bearing also.

thanks!
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kman
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by kman

My first thought was that the crown race may not be needed - some carbon forks are designed for the cartridge bearing to rest directly on the fork (eg Cannondale).
In the pic though, the crown race and bearing are definitely not mating correctly.

Check both these things and report back if you haven't fixed it. A tensioned installation of the headset/frame/fork would be a good idea, btu you should be able to tell without doing this, in my experience.
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flying
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by flying

I use FSA internal headsets & they fit nicely together
Not as shown in your pic...For some reason either you have wrong bearing or wrong
crown race?

Lower bearing is beveled bottom to sit on race & tapered at top into fork. (internal headset)

This pic is closest I can find to explain
p4pb8220182.jpg
Looking at your pic that bearing you have on there does not look like any internal headset lower bearing I have seen

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IrrelevantD
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by IrrelevantD

boleiro wrote:
Tue Jan 07, 2020 1:42 am
just started a new build and already hit a snag... the lower bearing sits high on the crown race. Shouldn't the bearing cartridge sit flush on the crown race, not on the angled part? This is making the gap between the fork and frame really pronounced.

per the pics... anyone have any information that might help. Thanks!

crown race 2.jpg
crown race 1.jpg
Neither of those photos look right. I don't think there should be a gap like that between the race and the crown of the fork. Bearing itself looks like it's either upside down, or making contact with where the steerer is bonded to the fork.
kman wrote:
Wed Jan 08, 2020 1:22 am
My first thought was that the crown race may not be needed - some carbon forks are designed for the cartridge bearing to rest directly on the fork (eg Cannondale).
In the pic though, the crown race and bearing are definitely not mating correctly.

Check both these things and report back if you haven't fixed it. A tensioned installation of the headset/frame/fork would be a good idea, btu you should be able to tell without doing this, in my experience.
I was thinking the same thing. I honestly can't recall the last time I had a full carbon fork that had a metal race. Maybe my '05 Tarmac, but definately nothing with a tapered steerer. They've all had a ~45º taper built into the crown for the lower bearing.

@boleiro, can you post pics without the race that came with the bearings? Do you remember having to take a race off when you removed the fork? Also, what is the model and year of the frame/fork? When you mention your "pvc tool" and adding preload to it, that concerns me as forcing a race or bearing someplace it's not suposed to be can cause damage, and your fork crown/steerer interface is not somewhere you want damage.
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joejack951
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by joejack951

IrrelevantD wrote:
Wed Jan 08, 2020 3:17 pm
I was thinking the same thing. I honestly can't recall the last time I had a full carbon fork that had a metal race. Maybe my '05 Tarmac, but definately nothing with a tapered steerer. They've all had a ~45º taper built into the crown for the lower bearing.
I would have thought the same but the picture showing the crown race on the fork made me think otherwise. If there was a tapered seat molded into the fork for the lower bearing there is no chance that crown race would be sitting as flush with the crown of the fork as it is. Also, you can see evidence of the slightly increase OD of the steerer in the area where the crown race is to be press fitted. This is all in line with a fork designed for a separate crown race.

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IrrelevantD
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by IrrelevantD

joejack951 wrote:
Wed Jan 08, 2020 3:59 pm
IrrelevantD wrote:
Wed Jan 08, 2020 3:17 pm
I was thinking the same thing. I honestly can't recall the last time I had a full carbon fork that had a metal race. Maybe my '05 Tarmac, but definately nothing with a tapered steerer. They've all had a ~45º taper built into the crown for the lower bearing.
I would have thought the same but the picture showing the crown race on the fork made me think otherwise. If there was a tapered seat molded into the fork for the lower bearing there is no chance that crown race would be sitting as flush with the crown of the fork as it is. Also, you can see evidence of the slightly increase OD of the steerer in the area where the crown race is to be press fitted. This is all in line with a fork designed for a separate crown race.
Ok, the way I was reading the conversation was that the crown race came with the headset bearings and my assumption was that the reason the race wasn't sitting flush with the crown was the taper of the race was sitting on top of the taper molded into the crown of the fork. Part of the reason I was asking if the OP could post pics of the fork without the race.
* There is a 70% chance that what you have just read has a peppering of cynicism or sarcasm and generally should not be taken seriously.
I'll leave it up to you to figure out the other 30%. If you are in any way offended, that's on you.

boleiro
Posts: 18
Joined: Thu Sep 15, 2016 4:31 pm

by boleiro

sorry for the silence... work. But I'll get more pics posted tomorrow of the fork without the bearing installed. To answer some questions:

1. the frameset is a brand new Cinelli Superstar Disc.
2. The headset including the race came packaged together. FSA C40 NO42. 42/52 but the lower bearing wasn't angled like it was advertised. I didn't realize it until after installing.
3. The fork steerer is carbon, but the base of the steerer where the crown race is installed is aluminum. Definitely requires a separate crown race.
4. The lower bearing was not angled at the inner or outer sides... I'm pretty sure this is the issue. the lack of beveled/angled sides is making the bearing sit higher on the crown race and headtube. I finally heard back from Cinelli (3 weeks later) and ordered the stock headset... this should work, hopefully.

this weekend I'll remove the crown race and should have the stock headset early next week.
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flying
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by flying

boleiro wrote:
Thu Jan 09, 2020 11:14 pm

4. The lower bearing was not angled at the inner or outer sides... I'm pretty sure this is the issue. the lack of beveled/angled sides is making the bearing sit higher on the crown race and headtube. I finally heard back from Cinelli (3 weeks later) and ordered the stock headset... this should work, hopefully.
For sure & like I said that is probably not a headset lower bearing...at least not one to be used with a tapered crown race or headtube for that matter

Good Luck correct headset should solve your problems

by Weenie


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