does anyone know how the star nut comes out of the center of a threadless stem?do you just drive it on thru the stem?i need to cut the stem a inch or so .and id like to reuse the star nut.thanks in advance
threadless headset star nut?
- Thread starter beentryin
- Start date
You can drive it through with a socket extension or something similar (top to bottom) and reuse if necessary. However, they're not designed to be reused. A new one is less than three bucks.
Star Nut at JensonUSA.com
Star Nut at JensonUSA.com
Just gently drive the nut a little deeper with a punch and hammer. Sometimes the riveted nut on those star nuts gets loose and spins freely. You might want to put a fresh one in. In which case simply drive it all the way out through the bottom. Then install a new one through the top.
Sheldon Brown's Bicycle Glossary St--Sz
Sheldon Brown's Bicycle Glossary St--Sz
My nephew had the same problem... what he did is put spacers on top of the goose neck, so he did not have to cut the stem nor replace the star nut... a lazy way of putting it, but you would spend probably a couple of dollars for the spacers. Then you can put lights or speedometer on top of the goose neck since it has an extension... 
Headset (bicycle part) - Wikipedia, the free encyclopedia
This picture shows the spacers that can be use without cutting the steer tube
http://www.sheldonbrown.com/images/headset-threadless.jpg
Servicing Bicycle Headsets
Star Nut
Star Fangled ® Nut
A special nut that is designed to be hammered into the steerer of a bicycle with a thread less headset, such as a Dia Compe "Aheadset" ®. The adjusting bolt screws into the "Star Fangled Nut."
The star-fangled nut has two barbed steel flanges that allow it to be forced downward into the steerer, but which prevent it from moving upward.
If you ever need to remove a star nut, the easiest way is by driving it down and out the bottom of the steerer with a hammer and punch.
Star nuts are only for use on metal steerers and should never be used on carbon steerers. Forks with carbon steerers generally come with special expansion plugs that serve the function of a star nut, without the sharp edges that might damage the fragile carbon steerer.
Star nuts are available in several diameters to fit different types of forks.
This picture shows the spacers that can be use without cutting the steer tube
http://www.sheldonbrown.com/images/headset-threadless.jpg
Servicing Bicycle Headsets
Star Nut
Star Fangled ® Nut
A special nut that is designed to be hammered into the steerer of a bicycle with a thread less headset, such as a Dia Compe "Aheadset" ®. The adjusting bolt screws into the "Star Fangled Nut."
The star-fangled nut has two barbed steel flanges that allow it to be forced downward into the steerer, but which prevent it from moving upward.
If you ever need to remove a star nut, the easiest way is by driving it down and out the bottom of the steerer with a hammer and punch.
Star nuts are only for use on metal steerers and should never be used on carbon steerers. Forks with carbon steerers generally come with special expansion plugs that serve the function of a star nut, without the sharp edges that might damage the fragile carbon steerer.
Star nuts are available in several diameters to fit different types of forks.