Neco Headset Expander Top Cap Star Nut Plug Bolt Stem Expanding Nut Bolt Carbon Fiber Cap Cover Long Large Size (Extra Large Alu Cap 1-1/8)

Great expander for the price! Functions and fits as it should and torqued down with zero issues.

Great product, I was able to repair my bike and get it back on the road

I bought the long one for my carbon steerer tube, and it is working fine with the extension I put on. I figure it'll give the tube some beef to strengthen it.

I was a little concerned by the people who posted reviews saying this compression plug slipped, even when torqued to spec. But, I decided to take a chance because I wanted something longer than usual in order to provide extra strength to the carbon steer tube. As it turned out, this design is no different than any other (except for the length). It is made well, and has a surface that is textured to grip well on the inside of the steer tube. It worked as expected, and just as well as any other. I question whether the people who said it slipped were in fact applying too much torque to the cap screw. Too much torque would definitely cause even a properly secured expanding compression plug to slip, but it's important to know that very little torque is actually needed when tightening down the capscrew. Apply just enough to prevent the headset from knocking. On my bike that was only about 3 N-m. Any more and you'll ruin your headset (the bearings). One other thing, the title -- Neco Headset Expander Top Cap Star Nut Plug Bolt Stem Expanding Nut -- is incorrect because this is neither a headset, nor a star nut. A better title might be "Neco Steertube Compression Plug / Expanding Nut, includes top cap".

These should be considered mandatory for any fork with a carbon steerer tube, as they prevent compression damage to the steerer. In addition to the stem clamp, the compression ring which centers the top bearing race of a threadless headset also compresses the carbon steerer, and does so exactly at the point where the torque exerted by the stem on the steerer is maximum. The damage to the carbon steerer is referred to in the carbon bike business as the “ring of death.” Therefore, one should use a compression plug tall enough that the plug extends inside the steerer below the level of the compression ring. The deeper the better, as if the steerer tube breaks, only the compression plug will give you steering control of the bike.

The top expansion wedge has a different angle than the lower one. Thus as you tighten it and the wedges pull together, the top expands more than the bottom. This means there will be more force on the inside of the steerer tube right at the top of the plug and less at the bottom of the plug. This seems pretty dangerous. You could easily damage the steerer tube with this localized force. I wouldn’t install this on my bike and just returned it.

Wont slip down in to fork tube because of ridge at top. Extends all the way down past headset bearing, giving support inside entire carbon fork tube. The top of my expensive fork had been overtightened with a small 3/8 inch long vertical crack starting at top of tube. I didn't want to cut the fork down any further so sought something that would provide more clamp support within the fork tube. After fitting this part and riding a couple of hundred miles on gravel, I disassembled for inspection and the crack has not expanded, I believe due to the support added behind the clamp area of the stem clamps. A bit heavy (alloy) but worth it for peace of mind.

Installed a carbon fork on my bike and kept the tube half inch over the stem so needed a little more support for tightening the stem. If your new carbon fork brings an expander plug, chances are it’ll be enough to cover just the stem. Just measure from top of tube to bottom of stem clamp and that’s the length you’ll need. You don’t want your bottom part of the stem crushing your new carbon fork

I’ve just installed it in my arrival mtb which has a rockshox lyrik ultimate. It has an aluminum steer tube. The star washers kept coming up when trying to preload the bearings. I tried different star washers and none of them worked. Soon as I put this new expander top cap it grabbed without any slipping. I’ll be testing tomorrow on the trail. As long as it works I don’t care about the extra weight. The description says carbon cap but it’s aluminum which doesn’t really matter. What is important is the fact that it allows you to preload the bearings properly.

Bought 80mm for my MTB, works just fine. And was delivered on time. Thanks! Nope, did not work well. I replaced it with conventional starnut.