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Headset Movement (Bearing versus Frame)


wilhelm-S
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I picked up some 'play' on my headset. Looking closer its seems to come from the top bearing... and more specifically there seems to be play between the bearing and the seat of the bearing (the frame). The bearing seems to sit loose within the frame regardless of the tightness of the headset assembly.

 

I have tried a new & old bearing, both fit loose withing the frame. With the cap installed there is about a 1mm gap between the cap and the frame...

 

Am I missing a shim / spacer or something?

 

Could it be wear & tear - microscopic movements chewing the frame  :eek:

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So, just double check you have the right size top bearing.

 

They come is 2 sizes. One is 1mm larger in outer diameter.

 

Another thing to look at is whether the top dust cap is actually putting pressure on the top race. There are often little half mm spacers on there to tweak it which people throw away.

 

Hope you get it sorted

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Nope, you're not missing anything. As Jewbacca says: just confirm that you have the correct bearing but that play is sorted by tightening the dust cap and stem.

Don't over tightening the dust cap as that will pull the butterfly out of the steerer. You may also need an additional spacer between the stem and dust cap if the steerer is too long for the stem alone.

 

Head sets are a b@tch to get sorted if the parts doesn't want to play ball  :cursing:. Good luck in getting it sorted

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Head sets are a b@tch to get sorted if the parts doesn't want to play ball  :cursing:. Good luck in getting it sorted

 

^^ This. And the Specialised team just loves to bring in their own unique standards.

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Often, through wear, design or slight variations in manufacturing, some play develops between the bearing and the frame. 

 

As the play is minimal, a simple shim, cut out of a coke can, works wonders.

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I installed a new bearing that looks identical, and once I picked up the movement - after a few rides, I re-installed the old bearing again just to make sure. 

 

But the play still persist even with the old bearing. 

 

If the dust cap is properly in place i.e. it puts pressure on the top race would that resolve the play between the bearing and the frame?

 

My logic tells me that due to the shape of the bearing seat, the harder the bearing is pushed down the more snug the bearing should be. The same goes for the race that pinches the steerer as its tightened... RIGHT?

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I installed a new bearing that looks identical, and once I picked up the movement - after a few rides, I re-installed the old bearing again just to make sure. 

 

But the play still persist even with the old bearing. 

 

If the dust cap is properly in place i.e. it puts pressure on the top race would that resolve the play between the bearing and the frame?

 

My logic tells me that due to the shape of the bearing seat, the harder the bearing is pushed down the more snug the bearing should be. The same goes for the race that pinches the steerer as its tightened... RIGHT?

 

 

Nope, you're not missing anything. As Jewbacca says: just confirm that you have the correct bearing but that play is sorted by tightening the dust cap and stem.

Don't over tightening the dust cap as that will pull the butterfly out of the steerer. You may also need an additional spacer between the stem and dust cap if the steerer is too long for the stem alone.

 

Head sets are a b@tch to get sorted if the parts doesn't want to play ball  :cursing:. Good luck in getting it sorted

 

 

^^ This. And the Specialised team just loves to bring in their own unique standards.

 

 

Often, through wear, design or slight variations in manufacturing, some play develops between the bearing and the frame. 

 

As the play is minimal, a simple shim, cut out of a coke can, works wonders.

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I found the problem... the dust cap (headset cap) was bent, and although the steerer is still counter-sunk within the stem the cap was in direct contact with the steerer and hence didn't push the stem downward onto the the top race, therefore not allowing it to clutch the steerer!\

 

Hope that makes sense!

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I found the problem... the dust cap (headset cap) was bent, and although the steerer is still counter-sunk within the stem the cap was in direct contact with the steerer and hence didn't push the stem downward onto the the top race, therefore not allowing it to clutch the steerer!\

 

Hope that makes sense!

This happens quite often, especially with caps that recess slightly into the stem.  A friend of mine was given a frame that had had a fork replaced after an accident.  After a number a of returns to the LBS it "was never right" and given away.  R15 on a 2.5 mm spacer and good for many more years.

 

Headset bearings are a minefield.  I have 20 variations in stock and there are many more.  It is not only the dimensions that are important but the seating angles as well.  Not always a case of take the one out as a sample because was the last mechanic on the ball? If you buy a new bike make a note of the bearings so that you can be sure to get the right ones in future. 

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