Broken head nipple, how to remove?
 

Hi,

The nipple was gripped, couldn't move it and eventually broke (half the head is missing), much like the nipples in this picture:

http://fcdn.mtbr.com/attachments/whe...y-img_3615.jpg

The suggested extraction method is to use a flat screw driver but the spoke is too ''engaged'' into the nipple and preventing me to use the flat screwdriver. Is there a special tool for this? Do I have to cut the spoke?

You can remove the nipples from the spokes on the opposite side of the wheel to allow you to push the spoke through the rim far enough to grab the broken nipple.

Yes, you should use a spoke wrench, not a screwdriver.

Here's how you can remove it easily if it isn't corroded onto the spoke.

Mount the wheel in the bike and tighten the QR. You'll need a pair of long nose pliers that can grip the nipple down in the well of the rim. Push the rim over at the brake (grab rim and stay or fork blade in one hand and squeeze) toward the damaged spoke or nipple, slightly - just enough to slacken the one spoke. Unscrew the nipple, and replace to roughly the same depth. let go and true.

I have a spoke wrench and tried to un-tighten the one that broke with it.
@Jiggle, Just to make sure I understand what you are suggesting is to unscrew the spokes to allow me to reach the broken one?

Do you suggest to change all the nipple since I will have undone most of them? I believe the material is brass.
@FBinNY, so you say, while the wheel is installed on the bike, I put the brake, put some pressure on the wheel (the damaged nipple is oriented like in the picture?), try to grab the broken nipple with a nose plier & unscrew? How should I position the broken nipple (toward me I bet)? Which spoke should I release prior to that?

Little diagram:
http://bikeforums.net/attachment.php...hmentid=417064

Loosening the opposite end will involve multiple spokes, roughly 1/4 -1/3rd of the wheel. If doing that, you might as well slacken everything, because it'll probably be easier to re-establish even tension. If you also want to replace all the nipples you have the option.

But totally reworking the wheel isn't necessary. My method should allow easy replacement and realignment. Even cutting and replacing the one spoke is easier. So consider the options and decide how much effort you feel is warranted for the wheel.

This is exactly what I'm NOT suggesting. line up the damaged spoke/nipple near the fork blade or seat stay. Grab the rim and pull it SIDEWAYS toward the blade, which will slacken/detension the spoke. Do this only enough so you can turn the nipple, because excessive side deflection can cause the wheel to spring into a potato chip shape.

BTW- if you lack the strength, or if the blade is too far for your one handed grip, you can deflect the rim by way of a tourniquet. Wrap a strip of cloth one turn trapping the blade and rim, with some kind of stick trapped. Twist the stick to tension the loop and slowly pull the rim across until you see the spoke begin to go slack. This method has the advantage of precise control, and is easier to hold while you make the switch.

Take a flat screwdriver with a blade that fits the spoke nipples well (width of blade and thickness of blade). Use a dremel tool with a cutting disc to cut a slot in the middle of the blade so the blade can fit on the slot on the spoke nipple over the protruding end of the spoke. Place a drop of a penetrating lubricant on the threads at the protruding end of the spoke, and another at both the broken part, and the other end of the spoke to aid in unscrewing the broken nipple.

Unscrew the broken spoke nipple.

Last suggestion is quite seductive!
FBinNY, I am a bit afraid not doing it correctly. Is there any video showing this technique? I'm quite a newbie!
The wheel is in the bike, I exert sideway tension and the spoke should come out of the rim, correct? Would it be easier/less risky if I loosen some spokes?
Should I sit on the frame of the bike or no pressure at all (beside the one I exert with my hand on the rim)?

Little diagram again to illustrate what I understood. Sorry, native french speaker here!
http://bikeforums.net/attachment.php...hmentid=417093

yes, but not enough to make the spoke fully slack or raise it in the rim. Just enough to lower the tension so the nipple turns more easily. If you want, try at a good spoke and se how the side pressure makes the nipple much easier to turn.

So you're only relaxing some tension, and will still need a long or needle nose pliers, or a modified screwdriver (see a prior post about making one) to remove the nipple.

I use vice grips on rounded and broken nipples.

Using vicegrips can be self-defeating. When you tighten the jaws, you are crushing the nipple body onto the spoke threads, making it harder to unscrew the broken nipple. Easier to use a modify screwdriver/nipple driver to remove the damaged nipple.

[QUOTE=RoadGuy;17297677] Using vice grips can be self-defeating. When you tighten the jaws, you are crushing the nipple body onto the spoke threads, making it harder to unscrew the broken nipple. . . . QUOTE]

Or, you can rotated the nipple 90 degrees in the vise grip, crush it again, and just remove the now more broken (preferably in half lengthwise) nipple. You might have to do it a few rotations, but brass is soft, and like a paper clip, will break eventually.The spoke should still be good if you didn't "Over Crush". Then you just replace the nipple and true the rim.

[QUOTE=hkhailey;17298538]That's pretty much what I've done.

Reading between the lines of the OP, I suspect that the OP's issue isn't with the shank (tubular extension) of the nipple, but with removal of the head which is recessed in a double wall rim.

He describes the shank as broken, so breaking it more won't help. Possibly there's enough left that he can grab and turn it with pliers or a vice-grip, but if not, he still has to remove the head, and if he breaks the shank off completely won't be able to turn it from that end.

Ultimately he'll need a purchase on the head itself, either with a screwdriver slotted to clear the spoke, or with long nose pliers, or some other way. My method of detensioning the spoke will reduce the needed torque and help with whatever method he uses.

One more method he might use.

Find or buy a socket wrench or nut driver which is slightly too small to fit over the head. Using a bench grinder, spin grind the OD at a shallow angle to form a circular chisel point. Tap it down over the head and it'll shave the head to a hex, then use a fresh nut driver to remove the now hex shaped nipple. (Do not try to drive it with the cutting edged tool whose thin walls will fail.