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Hi All,

Why I should never work on my own bike. Surprised I can even change a tire..

Anyway, I wanted to replay my stem and noticed I needed to remove the headset stem cap. Bike has a Chris King threadless headset. Instead of doing research to know that one only needs to remove the cap NOT loosen the screw in the start nut! The cap as a hex shaped hole which should have been a clue. But I a 5mm allen wrench will fit through the hex hole in the cap and it fits into the start nut screw. So I loosed the star nut and now the top bearing cap has an uneven 1mm gap and the bearings are not tight (wobbles).

Chris King's web site mentions a special tool and that the start nut should be 15mm below the top of the steerer tube. This is after cutting the stearer tube to be 3mm below the top of the stem. My LBS did not do it this way. They left the stearer tube longer and used spacers above the top of the stem so the headset cap would fit properly.

I assume the Chris King instructions should still apply, star nut 15mm - 18mm below the top of the stem. Has anyone put together a CK headset without their special tool for the star nut? I wanted to go on a ride today and tomorrow but looks like a no go. All the LBS's are closed. I am an idiot.
 

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I'm a bit confused about what you're talking about, your description is pretty bad. Are you replacing a stem? Or repositioning one? What did you do with the top cap bolt? You removed it then stuck an allen through the top cap and somehow moved your star nut?

A star nut should be at a depth of 15mm from the top of your steerer tube; a star nut setting tool is usually used to do this but it can also be achieved with other tools. You can use spacers on top of the stem, if you have a lot and it's not reaching the star nut then you could use a longer top cap bolt. You also need a gap of several mm's at the top of the spacer stack, or below the top of the stem if you have no spacers on top, to allow some compression of the headset on preload as well as to seat the top cap. You might want to review headset info on parktool.com such as this one http://www.parktool.com/repair/readhowto.asp?id=65
 

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tdiclub Member
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I am having trouble with a compression plug also

On a Look HCS 1" carbon steerer, I have re-inserted, came loose and went to my team LBS. Re-insterted and came loose again. I am guessing the mechanism on the plug is bad, ie not compressing. What other options to a compression plug are out there?

TIA
 

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Do not use a star ring in a carbon steer, use only a compression plug! If you are not very sure of what you are doing, take it to the LBS before you permanently damage something or risk having a component failure during a ride. If I understand your problem correctly and you are a competent mechanic, you need to reset the height (depth) of the compression plug. Completely remove the plug from the steerer. Screw the bolt in only 1 or two turns. Insert the plug into the steerer by pushing on the bolt. The plug should be positioned roughly in the middle of the stem. Set the preload by tightening the bolt, you may have to play with this a couple of times to get the correct preload with the plug in the correct position. Torque the stem bolts and all should be good.
 

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Attempting to use a star-fangled nut setup in a carbon fork will likely lead to destruction of your fork (at best) or a rig that you think will work but fails completely yielding serious injury. Compression plugs were designed to replace star-nuts. Don't be foolish and get yourself killed.
 

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BrknDreams6 said:
Hi All,

Why I should never work on my own bike. Surprised I can even change a tire..

Anyway, I wanted to replay my stem and noticed I needed to remove the headset stem cap. Bike has a Chris King threadless headset. Instead of doing research to know that one only needs to remove the cap NOT loosen the screw in the start nut! The cap as a hex shaped hole which should have been a clue. But I a 5mm allen wrench will fit through the hex hole in the cap and it fits into the start nut screw. So I loosed the star nut and now the top bearing cap has an uneven 1mm gap and the bearings are not tight (wobbles).

Chris King's web site mentions a special tool and that the start nut should be 15mm below the top of the steerer tube. This is after cutting the stearer tube to be 3mm below the top of the stem. My LBS did not do it this way. They left the stearer tube longer and used spacers above the top of the stem so the headset cap would fit properly.

I assume the Chris King instructions should still apply, star nut 15mm - 18mm below the top of the stem. Has anyone put together a CK headset without their special tool for the star nut? I wanted to go on a ride today and tomorrow but looks like a no go. All the LBS's are closed. I am an idiot.
Okay. It sounds like you're talking about a compression plug... not a star nut.

First off most star nuts have a 5mm allen key hole, and a 6mm hole on top of it. The 5mm bolt will loosen/tighten the whole assembly (which you did it sounds like), and the 6mm hole will compress everything together. You don't need some random star nut setter that the Chris King website mentions. I'm assuming that site assumes you're using an alloy steerer (not a carbon one like yours)... which is also probably why you're so confused.

To get it right, you're going to have to put the whole thing back together and loosen the top cap until it practically falls out of the rest of the assembly. Drop that into the steer tube, tighten the 5mm bolt (to get a grip on the inside of the fork), then tighen the 6mm cap (to compress everything together). Just play around with it. Hopefully you know how to adjust a regular headset. You should see how it works. Its pretty self explainatory.

Or you can just bring it to your LBS... Given you bought the bike from there, I'm sure they'll do it for free. It doesn't take longer than a minute.
 

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The preload on the headset cap is actually pretty important. Too loose and.....well, you know what happens already. Too tight and you will cause excessive wear on the bearings and possibly even make your steering tight and less responsive. The idea is to get it as loose as possible but with no lateral play at all. The difference between too loose and too tight is about 1/4 turn of the wrench. Learning to do it an get it right is an important skill in my opinion and I'd suggest you fuss with it until you get it right.

Test for play by applying the front brake and rocking the bike back and forth. You can feel play very easily. There should be none at all. But, if you pick the bike up, the steerer should swing back and forth just like it does when the headset is too loose. That's the magic spot. Good luck.
 
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