Star Nut Conundrum

[cmb5286]

Originally Posted by GregL

This has been covered in multiple threads over the years. I once removed a star nut from a Cannondale carbon fork (which was approved for their specific star nut). The previous owner had pushed the star nut down into the steerer tube and used a compression plug instead. Before building up the bike, I decided to remove the star nut and carefully inspect the steerer tube.

I secured the fork so that it could not move, then drilled out the star nut very carefully. The key was to NOT have the drill bit become stuck, spinning the star nut and ruining the fork. I started with a drill bit that was just slightly larger in diameter than the threaded center hole in the star nut. I then used progressively larger drill bits until the star nut fell apart. The process was quick, easy, and effective. The fork served me well for years to come.

Greg

I think the key here is not to have the star nut spin. Trying to think of a way to ensure this.

[charliedid]

Star Nut Conundrum sounds like an obscure 70' prog rock band

[MikeD]

Has anyone actually had a star nut spin, or are we just theorizing here? Is the center threaded portion aluminum or steel?

[AngryScientist]

I would first confirm that the star nut is not an approved solution based on the fork mfg, if not, I'd just push it further down and use a compression plug above it.

That steerer tube looks beefy and in good shape. All these cries to get a new fork are overboard IMO. It's easy to spend someone else's money though, I guess.

[nicrump]

I'm happy to be corrected but I've never, since seeing my first carbon steerer(30 plus years ago) seen a carbon fork with a carbon steerer that DOES NOT have an internal metal sleeve bonded spec'd with a old fashioned start nut.

Having said that, the steerer ID does look very clean, I'd push it down, only as far as needed to clear the compression plug as they often decrease in ID towards the bottom.

[Dude]

Originally Posted by nicrump

I'm happy to be corrected but I've never, since seeing my first carbon steerer(30 plus years ago) seen a carbon fork with a carbon steerer that DOES NOT have an internal metal sleeve bonded spec'd with a old fashioned start nut.

Cannondale, around early to mid 200s had a few forks that were carbon steerer, star nut and no sleeve. I worked at a shop, saw a bike come in like that, called Cannondale and they said “it’s supposed to be like that.” I was really surprised.

That’s the only one I’ve heard of.