Carbon steer tube

[Matthew]

I am about to put together a new Moots compact and it will be my first bike with a carbon steer tube. This is probably a silly question but do I use a compression plug or star nut? It is a Moots branded Alpha Q fork. Are there any tips to setting up a headset with this or any carbon steer tubed fork. It makes sense that I would not use a star nut as it will probably damage the tube on installation. Is this correct? Also, do some headsets come with a compression plug? I feel I should know this stuff already but I just want to make sure I don't screw things up. Thanks, Matthew.

[vqdriver]

i think in another thread it was said that its was safe to use the starnut in a carbon steerer. apparently, cannondale does this stock.

personally, i'd just assume use a compression plug. there's no reason not to.

btw, i get mine with the fork, not the headset.

[Peter P.]

Alpha Q uses a plug which is GLUED in place. The fork should come with the proper plug. Obviously, the plug is installed after the fork is cut to the desired length.

Instructions can be found at the bottom of the page, here (http://www.truetemper.com/Performance_Tubing/technical.asp) . Many people will find the glue supplied is not sufficient in quantity, so they buy extra, sometimes from the hardware store.

You're right; an star nut should not be used with carbon steerers.

[David Kirk]

No star nut please. Unless we are all named in your will then go nuts. Otherwise no star nut in a carbon steerer.

dave

[jmc22]

From the Alpha Q website:
Q: Do I need to use the Insert Kit supplied with the all-carbon forks? Will a compression plug work?
A: You must use the insert to comply with the warranty. A compression plug provides an anchor for the head set tension bolt. The insert does this and more. It also reinforces the steerer at the clamp area to support the clamping force of the stem better than any carbon tube with only a compression plug. Thirdly, the insert stiffens the top portion of the steerer for a more solid feel in the stem and handlebars where torque is generated. The insert provides the most solid connection possible and is well worth the time to install it.

[Serotta_Carbon]

[QUOTE=David Kirk]No star nut please. Unless we are all named in your will then go nuts. Otherwise no star nut in a carbon steerer.

Dave,

Thanks for beating me to this one!

Do not pound star nuts into carbon tubes!!!

[soulspinner]

No star nut please. Unless we are all named in your will then go nuts. Otherwise no star nut in a carbon steerer.

dave

:D

[Sparky69]

Congrats on getting an RSL :beer:

[Dave]

A lot of problems with the Alpha-Q can be blamed on the manufacturer's poor instructions, aluminum support tubes that were too short and too little glue supplied.

I installed on of these and it had such a large gap between the support tube and steerer that the tiny package of glue wouldn't even begin to fill the gap. Rather than use 5-minute epoxy, I mixed both tubes of some JB Weld and slathered it on heavily. I turned the fork upside down so the glue would not run down into the steerer and let it cure for at least 24 hours before using.

The tube is supposed to extend below the upper headset bearing. The instructions were not clear about that (at that time), but I wasn't using much steering tube spacer, so mine went plenty far into the steerer. The maximum at that time was only about 2cm of spacer, but a lot of users left the steerer long enough for 3-4cm and the result was a support tube that was not set deeply enough.

[oldpotatoe]

i think in another thread it was said that its was safe to use the starnut in a carbon steerer. apparently, cannondale does this stock.

personally, i'd just assume use a compression plug. there's no reason not to.

btw, i get mine with the fork, not the headset.

DO NOT use a star nut in a carbon steerer!! Regardless of what cannonbdale may be doing.

[happycampyer]

The fork should have come with a manila folder with the aluminum insert, some epoxy and the instructions. As others have said, many people prefer to use JB Weld instead of the supplied epoxy, and the instructions from Alpha-Q have left something to be desired. If you didn't get the packet with the fork, I would check with Moots who should have it.

Mr. Lopez,

Your participation here is greatly appreciated by me and many others I'm sure. Is there an F4 in the works perhaps?

[Matthew]

I appreciate all the help. I have not picked the frameset up yet so I was a bit uneducated on the Alpha Q fork and how they work. I feel a little silly now but am glad I turned to you knowledgable folks here on the forum anyway. Matthew

[jpw]

DO NOT use a star nut in a carbon steerer!! Regardless of what cannonbdale may be doing.

Why would Cannondale be doing it?

[oldpotatoe]

Why would Cannondale be doing it?

Posted by VQdriver-"i think in another thread it was said that its was safe to use the starnut in a carbon steerer. apparently, cannondale does this stock."

[Dave]

An "carbon" steerer that can accept a starnut must have an aluminum liner. The start nut digging grooves into carbon is a definite no-no. C'dale's instructions warn about any type of scratches being a potential cause of failure.

[Bob Ross]

re: Cannondale doing things differently

in a not-so-recent thread over on roadbikereview.com, I had pointed out that contrary to nearly every other carbon fork manufacturer, Cannondale does not endorse the practice of putting a spacer above the stem/under the top cap.
(The exact quote, from the apparently no longer available document http://www.cannondale.com/asset/iu_files/techcenter/2006_cannondale_carbon_fork_headset_stem_technote_ en.pdf was "DO NOT INSERT spacers between the top of the stem and top cap...It is very important that no spacers ever be installed above the stem, since this will raise the top cap and may allow the stem to crush the steerer tube.")

to which someone else responded
"Cannondale uses a long cylindrical plug to reinforce the steerer tube from the inside, hence the warning against top spacers. If you would put a top spacer on a Cannondale-plugged steerer, the plug might not reach down far enough to act against the clamping forces of the lower pinch bolt."

Not sure if this explains anything about Cannondale's use of star nuts, but it seemed somewhat germane.