Star Fangled Nut Fell Into the Steerer Tube. :'c
 

Hi there,

As I was riding home I started to feel that my headset was loose; there were strange noises I didn't like coming from there, and play.

So I went on YouTube, smashed in some how to's and got on my way to tightening the headset.

Here's what I did:

1. Loosened the two screws on the stem.
2. Removed top cap
3. Tightened the screw that attaches to star fangled nut. Play was still felt.

Logic: "huh, maybe it's something else that's causing the problem."

Not logic: "Let's see what happens when I loosen the screw."

4. Loosened screw that attaches to star fangled nut.
5. Watched sadly as star fangled nut descended 10 cm down into the steerer tube.
6. Tried removing the fork to see if I could get the nut out from the bottom. Then realized the bottom of the fork is not hollow....
7. Cried slowly and came to bike forums.


I'm wondering how I can take out the descended fangled nut; maybe by separating the steerer tube from the rest of the fork somehow? Is that even possible?

Or maybe I can get a really long allen wrench or a strong, thin magnet and pull it out from the top; but I doubt that considering the nut only goes one way.

Bah. May I have a hand please? :bang:

I can't make much sense of your post, but here's a try:
1) You could just leave the nut where it is and push a new one in place.
2) Maybe turn the existing nut over 180 degrees (use a punch) then pull it out the top.

I thought about just getting a new one in place, but then I'd still have the other one in for no reason, doesn't seem like a clean fix. l:

As for the second option, I can't really reach the nut as it's pretty far inside the tube, but I'll try to turn it if I find something long enough to reach it.

There is no screw to hold a star-fangled nut. What you must have is an expansion plug. If you loosen the expansion bolt, it will fall into the steerer. Turn the steerer upside down and it should fall out.

It's the top cap bolt that affects the headset bearing play, not the expansion plug bolt.

I pulled a well fitted star nut apart .. the 2 spring steel stars are fixed to the threaded center by an Aluminum
core riveted together.. once in parts they come out on edge..


that sounds about right, only a 1" type star nut in a 9/8" fork has any possibility of being Loose..
but if it worked before , i expect this ,( its not a star-fangled nut at all) was a distinct possibility.

Well, whatever it is, it's not coming out by just flipping the bike upside down.

I fished an expansion nut out of my CF fork with a piece of wire (and fork upside down) that the previou owner or shop mechanic had dropped in and left there.

http://bikeforums.net/attachment.php...hmentid=327639http://bikeforums.net/attachment.php...hmentid=327640http://bikeforums.net/attachment.php...hmentid=327641

This is the top cap

http://bikeforums.net/attachment.php...hmentid=327642
http://bikeforums.net/attachment.php...hmentid=327643
This is the dilemma; the now expansion plug is so far down, the laptop camera won't even pick it up.

If it is a star fangled nut , there nothing wrong with leaving it in there . Even if you were going to put a new one in there , the new one would drive the old one down deeper anyway . Just replace it and be done with it .

Got any tips?

You have (had?) an expansion plug in the steerer , not a star nut. The "top cap" you show has internal threads that screw down over a male extension on the body of the plug. Tightening the plug itself requires a 5 mm allen key used in a central 5 mm recess in the plug body. So, get a long 5 mm allen key and use it to reach down into the steerer to turn the plug bolt to loosen it further. Then shake it out.

Replace the body in the steerer far enough down so the top cap threads onto it securely to set the headset preload and tighten it with the 5 mm allen.

BTW, NEVER use a starnut in a carbon steerer.

I see, that makes things a lot simpler, now to find a long allen key. Hmm, maybe I can attach something to a shorter one to make it longer, kind of like when people use a wrench and attach pipe to it.

A few questions for you if you'd like to answer them: what's my 'top cap' actually called? What does pre-load refer to? And when you say 'body in the steerer', I'm assuming that means replace the expansion plug into the steerer, right?

(sorry about that, I'd prefer to ask and learn than shut up and learn the hard way)

then take the fork out of the bike,. probably just have to remove wheel from one end
stem from the other, and remove the brake caliper

if you cannot figure it out, at least you have it in hand, to take to your LBS ,
and maybe they are able to do it .. different approaches..




yea some Carbon steerer forks are not open bottom tubes , like metal steerer ones are..


good luck, happy fishing..

Get a set of 3/8" drive hex bits and use a long 3/8" extension to create a long hex wrench. If the thing fell down, it should fall back if the bike is turned over and you shake it a bit. A magnet might also work to pull it up. When you reinstall it, put some side pressure on the plug, so it doesn't fall down.

http://bikeforums.net/attachment.php...hmentid=327656

Screw driver + Hex key + Duct tape.

Yeah. :D

Couldn't have done it without all of your help!

Based on your questions, and they way you got into this problem initially, I have to conclude you are completely at a loss as to understanding how any of this works. At this point, I highly recommend taking the bike to a good bike shop and let them get it sorted out. THEN read a good bike repair manual or one of the on-line tutorials on threadless headset adjustment.

Hi,

Your problem was reading the wrong instructions for a different
type of headset arrangement to the one you actually have fitted.

You were correct up to stage 3.

With a starnut you omit stage 2 and simply tighten the central bolt
two finger tight, and then reverse stage 1, tightening the stem.

For your arrangement stage 4 should have been refitting the top
cap two finger tight to adjust the play, its possible stage 3 was
not necessary, as the plug and cap are only used to set preload,
the preload is held in place by a properly tensioned stem.

A long flat blade screwdriver of the right width will loosen the
allen bolt in the plug further, and hopefully letting it fall out.

Refit by screwing on the end cap 2/3 or so and adjusting the
central bolt so its a tight fit but will still push in. Then remove
the cap and tighten the centre bolt. It does not need to be
tight, two/three fingers should be fine. Then refit the cap
and use that to adjust the play, usually two fingers.

Then tighten the stem fully.

rgds, sreten.

The only way of replacing a star flanged tube nut, which
should never be necessary unless its over-torqued by an
idiot is to drive it out downwards with some brute force.

If the forks have no bottom opening you just move it
down out of the way and fit a a new star flanged nut,
tapping it into the tube with a hammer, bolt fitted.

That's some clear and succinct wisdom; agree entirely. There are some repairs/adjustments that if done incorrectly offer the opportunity for serious injury. Is your face worth it?

Bikes have been high-tech-ed seems people buy a bike past their mechanical skill and tool collection .

I, in the Shop , since I did something else for a few years , like Bike tours, when I came back

the gee whiz factor has moved down the price points a bit. and the stuff just racers used
was made compulsory by the manufacturers. and dangled in front of consumers .

by promotionally touting it all.. New ! Improved! ..

Maybe a CD with all the specific component service manuals could be included with new bikes

would you pay extra for that?

oh well at least it got sorted .. OP there are other compression plugs for carbon steerers some you just epoxy in the threads so the center bolt does not haveto do 2 things .
1st expand inside the tube. then pull down to preload the headset,

some use 2 separate wrenches and do one at a time.. .

Hi,

Screwing things up is all part and parcel of the learning process. Some will / cannot
ever learn and pretension abounds. Personally I would make no assumptions about a
persons general competence when they are posting about the wrong end of the stick.

rgds, sreten.

Well, I figured the expansion nut was there for good. I took some wire (say light coat hanger wire) and poked it. Imagine my surprise when it moved. The nut was the three piece kind with an Allen headed bolt with a center hole threaded for the top cap. I got a long Allen wrench and unwound the bolt with the bike upside down to make sure the tension was off the expansion nut Then I took the wire and bent the end slightly to I could stuff it in the the empty hole (of the expansion nut, the hole that the top cap screws into) and gently work it out as the nut was relaxed enough to slide out with a little teasing. Otherwise I would have left it there. I was surprised I got it out...twice. The 2nd time was because I messed up reinstalling and it fell back down.

Well, screwing up when the consequences are minor is one thing and screwing up when it can get you badly hurt is quite another. Headset adjustments, if done improperly, can fall in the later area. This is one place where you want to learn the right way first!

Hi,

I agree. But so far it is an inconvenience and if the expansion plug can be
extracted it will be straightforward to put back together properly and safely.

One assumes the stem must have been loose in the first place.

rgds, sreten.

Right, so after all of these shenanigans, I've learned this: the fork is simply a piece of nicely shaped metal that goes through the frame--but it needs something to hold it in place; using only the stem bolts as a clamp would work, but it's not enough, and it might damage the steerer tube over time, so manufacturers decided to add a second way to hold the fork/steerer to the rest of the bike. There are many ways to go about this second step, including the starnut and the adjustable plug. I had the latter, and all it is is a small piece of metal which expands as a bolt goes down it's thread, allowing it to stay held to the walls of the steerer. This now stuck piece of metal acts as an anchoring point that can be used to pull up the steerer/fork and hold it in place. This hoisting is done by the end cap,which has internal threads that attach to that small piece of metal in the steerer tube. The more I tighten this end cap, the more compressed the entire fork/frame/stem assembly will be, or the amount of preload it has; which affects how freely the bearings can move, and in turn, how freely the whole system moves.

So, keeping all of that in mind, this is what I did to put the plug back in, step by step, as you instructed.

1. loosened the stem bolts

2. screwed in the end cap to the plug 2/3 of the threads

3. Placed the end cap/plug into the steerer tube as far as the end cap would allow.

4. Partially tightened the plug bolt, allowing the plug to anchor itself into the steerer tube, but still allowing it to move down if necessary.

5. Removed the end cap, because you told me to

6. Tightened the plug bolt more securely; it was now wholly anchored in.

7. Screwed the end cap back on, this time screwing it down until there's no play in the headset. The system was now held together vertically; I couldn't pull apart the stem and fork by mere force if I wanted to.

8. Re-tightened the stem bolts using the manufacturers recommendation, without a torque wrench as I do not have one. The system was now secured horizontally, the wheel and fork and handlebars became one continuous mechanism; they all moved dependently with one another when turned.

9. Checked to see if the system is free enough by lifting the bike and swinging the handlebar/fork/wheel back and forth; if it moved freely and even, I'd be set; if the movement was choppy and uneven, I'd have to try again.

10. It was free, and even.

Only thing that strikes me as different from when I started this morning is that the steerer/fork now moves independently when the two stem bolts aren't screwed in, even if the end cap & plug are in place. It didn't use to do that, but maybe that's because I've now messed with it, so it's more malleable than when it rolled out of manufacturing. (By the way, in case if you are all curious, I didn't buy this CAAD9 from a bike shop, I got it off of Craigslist on the cheap, practically new, and with no manual).