Why do some Zero Stack semi-integrated headsets have an extended top cover?

For sportive riders who can’t slam their stems.

Beats me. Had one of these on my Reign and it sopped me getting the bars low enough so I took it off. The headset works fine without it but is slightly more exposed.

I think its so you can get the correct axel to crown height, which may require a zero stack at the bottom of your headset. You may not need to lower the stem on top.

alternitively its to stop dumb asses slaming their stem so far that they find they dont fit the next frame then posting threads on here with nonsense about steerer extenders etc etc

I think its so you can get the correct axel to crown height, which may require a zero stack at the bottom of your headset. You may not need to lower the stem on top.

As the name suggests “axel to crown height” is the fixed distance between the fork axle and fork crown, a headset won’t change that 😉

Frames are designed around traditional, semi integrated or integrated headsets- the frame determines which one you need.

The reason for the extended top cap cover is simply to replace the normal spacers. They are generally sold in a variety of sizes to get the right fit. Only reason for this top cap on the headset is aesthetics over normal spacers really…

DanW – I meant that some Headsets stick out below the frame more than others, so that would extend the axel to crown height.

But as you say, its got nothing to do with the top part though, only the bottom bit.

I had to get a zero stack for my bike and Chris King didnt do one, so I went for a hope one. I was not worried about the top bit as I have a 5mm spacer under my stem. But the headset needed to be flush with the bottom of my frame for the forks to be just right.

The reason for the extended top cap cover is simply to replace the normal spacers. They are generally sold in a variety of sizes to get the right fit. Only reason for this top cap on the headset is aesthetics over normal spacers really…

I’ll go with that. Ta.