I think my star fangled nut is screwed....?

[steady10101]

Hi

im i need of some help...or it's just me being stupid

when trying to tighten my top cap it just spins....now ive been told this is due to my star fangled nut not holding in place and to fix it it would need to be knocked down from the top......

my question is if i cannot remove the top cap as it is just spinning with the sfn how am I supposed to do this.....?

(sorry if posted in the wrong place or being posted before....i did look )

 

[Rohloff_Brompton_Rider]

first thing is to see if either the nut or bolt thread is stripped. take a hammer and a piece of wood or something similar to stop the hammer damaging bits. you need to either knock the forks downwards or handlebars upwards. the idea being to get some bite. try this several times in between each effort try and undo the bolt (ccw). if this doesn't work then the only options left are either drill out the bolt head or sacrifice your stem / bars clamp and hacksaw above the steerer tube perpendicular to the floor.

once you have removed the stem and can see the star nut, you can make a judgment on which bits need replacing.

if you have a soft top bung (bit the bolt goes thru) eg, plastic, alloy etc then you can take a drill with a small drill bit and drill a circle of small holes around the bolt head and pull the stem off (takes a bit of force but does work)

or get lbs to do it for you.

 

[02GF74]

are you sure it is star nut? they are not supposed to be used for a carbon fibre steerer, but instead an expanding type bung is used. ofcrouse there is no reason why that type of fitting cannot be used in a metal steerer - they are notorious for spinning round.

you need to take the bolt and cap out to see what is going on inside; then post again if more advice is needed.

 

[steady10101]

you see the thing is i cant get the cap and bolt out as they just spin round and round....and i can see its a star nut when i look up the bottom of the forks and they aint carbon so it would be a star

 

[Jonathan M]

A few things come to mind here:

Does the SFN manage to hold the thread on another bolt?

Could the SFN be too far down the fork steerer?

Are you using the right bolt (is it long enough?)

 

[MartinC]

If you can see the sfn then that's a good start. It sounds like either the thread has stripped or the threaded sleeve in the sfn is turning in the star part.

If you can look up from underneath the forks while you turn the nut you might be able to see what happenning. One of those jobs where you'll need at least 3 pairs of hands and a light in the right place - where your head is.

If the thread has stripped then I'd suggest putting a drift on the bottom of the bolt from below - through the hole at the bottom of the fork crown and driving it upwards to try and get new thread to engage. If you manage to get the bolt to move up 5mm or so you should be able to cut it with a hacksaw underneath the top cap.

Another avenue of attack might be through the spacers. If you can Dremel one of these off then loosening the stem may give you enough space to get a hacksaw blade underneath the top cap.

If the bolt is spinning in the sfn then drilling it may be difficult.

Big hacksaw across the top cap may work - cut it in half. If there's a spacer on top of the stem this may not even touch the steerer tube.

 

[e-rider]

if it just spins then try just lifting it off (remember to loosen the stem bolts first)

 

[youngoldbloke]

Screwdriver from below through SFN to jam it/stop it moving enough to unscrew bolt? Otherwise +1 to lifting off, using bars to pull upward.

 

[steady10101]

just to let every1 know its ow sorted thanks to advice of a few of you....

i put a large drill bit up through the bottom and hit it hard to try and get the sfn to hold in place...this didnt work but a managed to hit the whole thing and top cap out of the top

upon further inspection the silver spacer between the 2 star nuts had grooved where the sfn's attach.....

cheers for the help folks