Author Topic: Lower headset gap?  (Read 1525 times)

kbernstein

Lower headset gap?
« on: May 05, 2024, 01:53:41 PM »
I have a ~2mm gap I don't understand and can't fix that didn't use to be there. This is from a carbonda 696 with the supplied headset, barely ridden only about 50km worth of shakedown rides
The lower split crown race don't sit flush with the lower headset bearing no matter what I do, I can't press it with my hands, tightening the steerer plug does nothing and there is no excess grease
I've tried fully omitting the split crown race like some people report but it steers like shit. But the gap disappears which confirms this is the culprit
Unless I'm crazy I think they used to sit flush and are supposed to



« Last Edit: May 05, 2024, 01:58:12 PM by kbernstein »



ausmtb8989

Re: Lower headset gap?
« Reply #1 on: May 16, 2024, 05:41:13 AM »
I also have the same problem with my LC MTB and that was provided headset.  Provided compression is nice and tight and there is no play, I haven't had any issues with the gap

kbernstein

Re: Lower headset gap?
« Reply #2 on: May 16, 2024, 06:57:31 AM »
I also have the same problem with my LC MTB and that was provided headset.  Provided compression is nice and tight and there is no play, I haven't had any issues with the gap
I've been rudely told elsewhere that was normal and I was a cretin for even asking. From all the 696 pictures I've seen none had such a gap but I couldn't find a closeup of the headtube. If a 696 owner can confirm? Also are the ZTTO or viaron headsets any good as a replacement?

Tijoe

Re: Lower headset gap?
« Reply #3 on: May 16, 2024, 07:13:19 AM »
There are 2 different headset bearing designs. One with 45 degree angle and the other being 36 degree angle/chamber.   One really doesn't want to mix and match the different angle bearing to different fork/centering rings.   With the above stated as one possible problem,  gaps are common even when the fork/centering ring and the bearing have the same angles.
(Tolerance stack up.)  Different bearing manufacturers can machine in larger or smaller OD chambers that cause the bearing to sit higher of lower on the fork/centering ring.  The same machining tolerances can happen with the centering ring.   

Almost all of my recent bike builds have a 1-2mm gap. 

Sebastian

Re: Lower headset gap?
« Reply #4 on: May 19, 2024, 01:55:58 AM »
There are 2 different headset bearing designs. One with 45 degree angle and the other being 36 degree angle/chamber.   One really doesn't want to mix and match the different angle bearing to different fork/centering rings.   With the above stated as one possible problem,  gaps are common even when the fork/centering ring and the bearing have the same angles.
(Tolerance stack up.)  Different bearing manufacturers can machine in larger or smaller OD chambers that cause the bearing to sit higher of lower on the fork/centering ring.  The same machining tolerances can happen with the centering ring.   

Almost all of my recent bike builds have a 1-2mm gap.

+1
Looks like your crown race clearly doesn't match the bearings inner race. Therefore the bearing sits on top of the crown race. Get another bearing or an entire lower headset. I can wholeheartedly recommend the CaneCreek 10 series enty level headsets. On the cheap side and still very good and durable.