Hi all,

Got another strange one.

Has anyone ever experienced this.

Got a Solaris Max frame I’m building up for a mate. With my fox 32s the superstar headset works fine (tapered steerer).

Move the crown race over to his new pikes I’m fitting and they bind. It appears that the taper on his fork starts about 3 or 4mm higher up the steerer than on my 32s.

It means that the steerer is fouling the middle part of the headset cup as it is inserted.

I’m thinking we need to order a different lower headset cup- probably a hope one.

The current one is a cheapy superstar one.

Is it 100% a steerer headset compatibility issue or could it be the pikes steerer isn’t machined correctly in which case they will need to go back.

I’ve measure with a caliper and my 32s have about 20mm before the taper starts. His pikes have about 23mm. That’s with no crown race fitted.

All of this is with the same crown race and bearings etc.

Anyone seen this before on an ec44/40 lower cup?

Cheers

Sounds v odd. Don’t wish to infer stupidity, but are you sure you have installed the bearing? Yes, I’ve made that mistake before.

Yes. You can see the lip and a tiny score on the anodising of the steerer.

It’s a 44mm head tube and it’s like the superstar one doesn’t sit the bearing proud enough. But it could be these new forks don’t taper soon enough (manufacturing issue).

Do you have a friend’s frame and forks to play working out….?

Sounds like a headset problem to me, a 44/40 lower cup should be able to take a 1.5 steerer no problem, therefore the start of the taper on the steerer should be irrelevant.
Can you measure the inside diameter of the cup?

I can. I’ve ordered a hope bottom cup. Figure I can see if it runs freely before fitting the cup to the frame. Send the headset back if the fork is the issue.

External, integrated, semi-integrated problem?

Note that I’m not sure I’ve got the problem right – my understanding, not your explanation, to blame.

There is no standard on the steerer taper so it’s perfectly possible you’ve simply hit an incompatibility.

you need a external bottom cup on the cotics (it’s how Cy designed them) even if you running a 1″1/8 straight steerer.
Hope HSCH https://www.hopetech.com/_repository/1/documents/Hope-Lower-Headset-Compatibility-Chart.pdf

https://www.cotic.co.uk/geek/page/tapered

It’s the lower Superstar headset cup. A friend had the same issue, I think he trimmed/machined a bit off the cup.

I have one sitting in my spares box, he recommended I did the same.

Ah that helpful breadcrumb. Thanks.