Carbon steerer rings, ring of death

Hey,

A very thoughtful forum member recently reached out to me about some full carbon forks I had up for sale. There are 2 imprinted rings where the bearings would sit on the steerer which I thought little of at the time. He pointed me towards information that clearly shows it can lead to failure.

I am posting here to see what people may know about this and to also bring awareness to anyone like myself who may of overlooked this issue without any information.

I know next to nothing about this other than steerer failure is fatal. Any information is appreciated!

I will try and update information here that may help people when I understand it a bit better.

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Minimals that’d been used with a king headset?

I noticed the band in your ad.

King headsets are shite for this.

In this case it doesn’t look very significant. If you lay something like a steel rule or Stanley blade up against the steerer it’ll illustrate a lot more clearly how much (or little) wear there is.

I’ve bought an alloy steerer fork with quite a significant groove (also from a King headset) but the price was right in that case and I would definitely be more reticent to buy a carbon fork with any kind of damage.

If the damage to your steerer is as minor as it looks and you can photograph them to show that more clearly then you’ll probably get them sold for a decent amount.

I had decided to keep them before discovering they may be a risk. I agree the damage is probably as little as it could be and I'm considering my options with them.

They are minimals with king headset but I'm unsure if it was due to the previous headset being loose for a while. I never saw them between the change and can't remember if it was there when I last greased the bearings.

A few sources I found reckon loose headsets are to blame but there seems to be several theories about how it can happen.

I'm considering gluing a metal pipe inside for safety if I decide to keep.

Edit: the top bearing cover is a tight fit on the steerer but it is a good cm above the highest band. The rest of the headset doesn't seem to touch the steerer but I could be misunderstanding how it all works.

Circled here is what looks like a crack but it is infact a scratch about double the depth of the rest of the indent. Apart from that, it's even.

I will get some better photos tomorrow with a rule against it.

Thanks for the reply!

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Leuscher teknik has done a youtube video titled steerer fork failure. The first fork he talks about is a bianchi fork with the rings from the compression ring worse than yours plus a couple of other issues as well but he did say it can kill you so this fork was taken off the road. Sorry i can't post a working link but should be pretty easy to find.

I think it can be the actual headset cup that makes contact with the steerer or the very edge of the bearing or something.

IMO it’s a pretty fatal flaw in King headsets and it’s very telling that they defended their decision not to pay the licence fee to use the wedge system by saying their design was better yet changed to a wedge design as soon as the licence ran out.

It seems like it’s a known problem (especially among mechanics, show any decent mech that steerer and they’ll know you’ve used a King headset) but for some reason no one wants to call CK out on it. Like CK stuff holds such reverence that folk don’t want to talk ill of it.

All I know for certain is that I’ve personally never come across that kind of steerer damage that was caused by anything other than a King headset.

I do have a King headset on one of my bikes (it was in a bundle of stuff I bought which included the fork with the damage that I mentioned in my last post) but I threw away the CK scuff washer and top cover and run it with a wedge and top cover off an £8 eBay fake.

I don’t think the structural integrity of your fork will be affected really. Afaik the damage happens via wear and not compression so the damage you see on the surface should be the extent of it if you know what I mean.

Cheers, I will find and watch it. The more to put me off the safer my face is!

That's good to know and I agree, its surface wear for sure.

I will most likely go with it and check often to see if it gets worse.

It puts me off CK a lot. I will look into replacing the right parts to improve it as I have one on another bike too.

I actually don't have the scuff washer on either of the headsets. I never knew they were a thing as neither had them.

@M_V is this the wedge version?

https://www.merlincycles.com/chris-king-inset-griplock-bearing-cap-1-1-8-215540.html?utm_source=PHG&utm_medium=AffiliateMarketing&utm_campaign=phg-GB&ucpo=133478&gclid=EAIaIQobChMInKKb1OCh7wIVybTtCh2QSQQOEAQYASABEgLQKfD_BwE

The same guy has done a video on fork steerer compression plugs and says long sleeved compression plugs offer the best support and may be better than glueing a pipe inside for support as you may struggle to even get a decent compression plug in once you've added extra material to the inside. The same guy has done loads on carbon steerers I'm just watching them now and what has really surprised me is how often he describes something as severe delamination on things i would have considered minor cosmetic and totally fine. He's a carbon expert and i barber so I'm going take his advice on this and check all my forks now. Starting with the one with a Chris King.

Not entirely sure.

I remember I tried to find CK branded versions of the bits I needed and gave up. I already had the fake headset so tried it out and it was close enough.

A long compression plug makes sense and my steerer is short so if it cracks, in theory it would still be held in place. That's worst case too so I think it would be ok. Edit: I would most likely see damage before it is fatal.

I'm going to start watching. I'm sure half my bike parts will be at risk now!

This is a pic of it in parts. It seems right with the split retention clip?

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Ah ok yeah that looks like it.

I looked at it on my pone before and couldn't/didn't see that image.

Great, I will probably invest in one then. I reckon getting a 1 inch one for my other bike may not be possible though.

Interesting. I also have a groove in my carbon steerer from the older style CK headset, later replaced with newer wedge style top parts. Mostly because the original repeatedly worked loose though.

The bike's been relegated to the turbo for the foreseeable future though. Might have another look, can't really remember how bad it is. Didn't realise it was a widespread issue.

I reckon getting a 1 inch one for my other bike may not be possible though.

Top bits of this might work (if it really is 1", the photo is obv of a 1 1/8" headset).

Good call, cheers!