Integrated headset cups wearing down .

[accountantpete]

The point of integrated headsets is that the bearing does not contact the inside of the headtube directly as this would lead to wear and the loss of the frame.

Bearings are made to drop in but when the top cap is tightened the angled base of the bearing contacts the angled ledge thereby locking the bearing in place - there should be no movement of the outer bearing, just the centre.

The OD of the bearing can vary slightly as the efficiency of the system is mostly based on the angle - did you ensure that the angles of the new bearings matched that of the old ones?

 

[Yellow Saddle]

The Aheadset style headset on which all modern headsets are based is widely misunderstood. Headsets experience forces that no other bearing on the bike experiences to that extent and that is flex at the fork crown. If the bearing cannot move in the frame (like in older screw-in headsets) then the flex happens inside the bearing itself. The fore-aft flex in the fork from rider weight and obstacles causes the bearings to temporarily bind and slide instead of roll. The vibrational nature of this creates strong fretting, which we saw clearly in the fore-aft pitting in older headsets when they became indexed.

The aheadset patent calls for a bearing that can move inside the cup, so that flex happens between bearing and cup instead of between bearing race and ball. Hence, Aheadset headsets have loose bearings. No matter how stiff the fork and steerer, it still flexes. The entire headset is a wear part but in reality wear is slow. However, by seating the bearing directly in the frame - especially a carbon frame that cannot be machined nicely, you are looking for trouble. We see this in ovalising of the frame's head tube.

Preloading or tightening it does hold it in place when unloaded, but as soon as the bike is loaded, there is stress on the headset and movement has to go somewhere. Some manufacturers like Cannondale have addressed the problem with square bearings - square in that the bearing race outer looks like a standard cartridge bearing instead of the angled edge. This saves the frame but compromises the bearing's longevity.

We have made no progress with headset design since Aheadset was patented 25 years ago. The Aheadset was a huge leap forward but carbon and weight weenies have ruined it's utility. BBs have gone the same way. Since square taper nothing has mechanically improved, only gotten lighter. I'm a retro-grouch that doesn't like backwards progress.

 

[RecordAceFromNew]

We have made no progress with headset design since Aheadset was patented 25 years ago. The Aheadset was a huge leap forward but carbon and weight weenies have ruined it's utility. BBs have gone the same way. Since square taper nothing has mechanically improved, only gotten lighter.

+1.

The wear of a traditional aheadset bearing cap shown below from here is as good a proof as any that integrated headset is fundamentally inferior mechanically to traditional and semi-integrated, but of course wear is always dependent on use and to some extent the original fit etc, so ymmv.

 

[accountantpete]

+1.

The wear of a traditional aheadset bearing cap shown below from here is as good a proof as any that integrated headset is fundamentally inferior mechanically to traditional and semi-integrated, but of course wear is always dependent on use and to some extent the original fit etc, so ymmv.

Yes - but that will be a lightweight aluminium cap which is designed to wear out. The internals to the headtube are made of harder wearing metal.

There are millions of bikes with integrated headsets but I see relatively few problems arising even after many years service.

 

[Yellow Saddle]

Yes - but that will be a lightweight aluminium cap which is designed to wear out. The internals to the headtube are made of harder wearing metal.

There are millions of bikes with integrated headsets but I see relatively few problems arising even after many years service.

No, they're not. They're made from the same stuff as the rest of the frame. Soft au or carbon.

There may be millions of bikes out there with integrated headsets but that doesn't make it a good idea.

 

[Yellow Saddle]

+1.

The wear of a traditional aheadset bearing cap shown below from here is as good a proof as any that integrated headset is fundamentally inferior mechanically to traditional and semi-integrated, but of course wear is always dependent on use and to some extent the original fit etc, so ymmv.

This failure is not from the type discussed here. This is a Chris King headset from a few years back. Chris King was too "special" to pay the licensing fees to Aheadset and instead, tried to bypass the patent with its own design which was crap de-luxe. Instead of using a compressing conical split ring at the top, CK decided to go for a flush fit bearing instead that slip-fitted over the steerer. This caused a deep wear ridge in the steerer and lots of headset play. So much so, that the caps came out of alignment during braking and fretted against the other parts, often with an audible (and certainly tactile) clunk.

It just so happens that when the patent expired a few years back Chris King decided that a compression ring was a good design after all (especially now that it was free) and implemented it. I have zero respect for such shenanigans. Good design should be rewarded with royalties. The rest of the industry gladly paid the pittance of a royalty on the millions and millions of cheaper-than-CK-headsets they produced.

 

[User6179]

The OD of the bearing can vary slightly as the efficiency of the system is mostly based on the angle - did you ensure that the angles of the new bearings matched that of the old ones?

Yes same angles 36 x 45 , I would guess if the angled ledge wears down then the bearing cant contact it then the upper part of the cup would need to hold the bearing in place .

 

[User6179]

Just back from a 50 miler and still no play in headset with the insulation tape wrapped round the bearing .

 

[mistera]

I know this is an old post, I have a similar problem on an old Klein. Thinking of using the baking soda and superglue trick, however want to know what happens when you need to replace the bearing if you have super glued it in?

 

[Yellow Saddle]

I know this is an old post, I have a similar problem on an old Klein. Thinking of using the baking soda and superglue trick, however want to know what happens when you need to replace the bearing if you have super glued it in?

It's not a problem. It will not be stuck so fast that you can't get it out. Superglue is not that super.