Stay Away from Shimano PRO Headsets!

I got lured by cheap prices into buying a Shimano PRO brand headset, and I wish I hadn't.

What follows is the email I sent to my Shimano rep. It should lay out the most egregious issues with the headset.

Hello, 

I'm having an issue with a brand-new PRO 1 1/8th" External Cup headset, and I was wondering if anybody else had this issue. What's going on is that the headset has play unless I crank it down hard, but then it doesn't turn well, obviously.

Here're the bullet points:

• While tightening, I have to go past the point in which the steerer can turn on its own from the weight of the front wheel before the play goes away. 

• I took it apart and inspected the compression ring, and noticed it has a tiered design so that it actually fits into the upper part of the headset like a Lego piece. I figure this is preventing the wedge from expanding as it would with a different headset (just a theory) so I tried using another brand's wedge, but it wouldn't fit under the PRO upper.

• I checked the bearings and they're fine. PRO crown race on the fork looks fine too. 

The headset came fresh out of a new box from Shimano and I don't think I'm missing any parts. The parts I have all look cosmetically fine, and the cups went into the faced/chased frame without issue in the same way I've done for years. 

Any guesses? 

Thanks

The rep Shimano set me up with admitted right away that he'd never used or installed a PRO headset, then he asked some dumb questions that amounted to nothing, and that was it. If he comes up with a solution at a later date, I'll change this post to reflect that, but it's been a week so far and the problem persists. This speaks to a bigger issue within Shimano though. Not only did they release a poorly designed component onto an unsuspecting public, but they didn't even train their reps in ways to mitigate questions about their dumb design. "Duh, I've never worked on one a them before" is not an excuse I can stomach from a company representative! Shimano is acting increasingly like SRAM these days and it has me worried.

Below are some pictures that show exactly what the problem is.

I'm usually don't judge on aesthetics, but the PRO headset is thick, blocky, and gross looking. I think the stack height on that lower cup is almost a centimeter. 

This is what the upper cup and cap look like. 

As you can see, the compression ring has a notch, or tier that fits into the bearing cap. I'm guessing this has something to do with the headset play because otherwise there's no difference between this headset design and any other. Why they did that, I can't imagine. The compression ring on the FSA headset below doesn't notch into the bearing cap and it works great. 

FSA compression rings are flat on the top. You can see that the ring makes a cone that corresponds to the bevel on the inner bearing. There's another cone on the fork that does the same thing. Together, they sandwich the bearings to the cups and headtube to make a snug, solid mechanism that moves rotationally but not vertically or laterally. 

Another view of the stupid shelf design on my workbench. 

Update: another mechanic got in the fray on an online message board I frequent and said that the problem could be more than the ring, that the source might be from poor machining or a fundamental design flaw in the bearings. He had some proof to back it up, but I won't publish that because without a way for me to test his proof, it seems a little like educated speculation (which I'm not against, since that's what this whole post is, really, but I don't want to drag him into it). At this point, sure, I suppose I agree. Point is, the Shimano PRO headset is just not a good headset by any definition. The online person suggested I switch to a different brand, and I think I will. Waste of money! Ahhh!

Double Update: I switched to a Cane Creek 40 headset, and all my problems have been solved.