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Any ideas on how to get a broken screw out of the hole?

33K views 33 replies 14 participants last post by  TomH 
#1 · (Edited)
I putting the water bottle cages onto my brand new carbon fuji road bike and everything was just peachy until the last screw. I tightened in increments set the torque wrench to 3Nm. Tested the wrench on my bed to make sure it was in fact very low torque. Well, I was doing the last bit of tightening when I heard the crack..... Heart sank, instantly sick to my stomach. Undid the top screw and saw that the screw snapped off in the hole.

On all of the other screws, the torque wrench "broke" with hardly any force at all, which makes me think it was a faulty screw. At least I hope it is because I forgot to undo the rest of the screws before leaving for class. Nevertheless, I now have a screw stuck in my frame. :mad2:

How exactly do I get this out? I was planning on bringing it to my lbs after class at 4:30, this has to have happened to more people than just me. And also getting the torque wrench calibrated somewhere before I use it again.

Am I screwed? (no pun intended)

The Fuji manual for my bike says between 3Nm and 4Nm but no more than 4Nm.

Thanks for the help...

EDIT: Also, should I have my roommate (who knows bikes) go take off the other waterbottle cage? In case those screws are over-torqued?
 
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#3 ·
The shop will use something called a screw extractor. they drill a hole in the stuck screw, and thread in the extractor, which is basically a tapered screw with coarse reverse threads. Hopefully it grabs the broken screw and backs it out. It's a bit of a pain with a screw that small.

Why didn't you listen to Kerry, and just use a little allen key and gentle finger pressure? ;-)
 
#4 ·
You mean you sheared the head off the machine screw?

One way to get rid of these is to drill them out. The best is with a left-threaded drill bit, because sometimes the drill unscrews the screw. Otherwise, putting a hole through it tends to relieve some of the pressure on the screw, so it's easier to get out some other way, maybe with needle nose pliers. If that's not working, a purpose-built stuck bolt removing kit can help. It comes with a tool that cuts threads into the inside of the screw, to get a better purchase on it.

Of course, that involves taking a drill to your new carbon fiber bike. If you're not pretty confident you can do it without damaging the frame, the LBS might be a better choice.
 
#5 ·
wim said:
Bring it to a bike shop and have them get it out. For one, the extractor you need may cost more than what the shop will charge you. For the other, advice given here doesn't seem to impress you all that much. So there's a chance you'll do more damage.
http://forums.roadbikereview.com/showthread.php?t=226675

Thats probably what overtorqued the screw in the first place.... I may be a little heavy handed... Thats why I bought a torque wrench:idea:

Thank you for you concern, and advice though. I definately was not going to touch it myself. haha
 
#6 ·
JCavilia said:
The shop will use something called a screw extractor. they drill a hole in the stuck screw, and thread in the extractor, which is basically a tapered screw with coarse reverse threads. Hopefully it grabs the broken screw and backs it out. It's a bit of a pain with a screw that small.

Why didn't you listen to Kerry, and just use a little allen key and gentle finger pressure? ;-)

Must be my massive finger muscles... I wanted to redo them with a torque wrench incase I was a little heavy with the pressure... I'm a little OCD, sometimes thats not a good thing. :rolleyes:
 
#7 ·
Calibrations

Nick09 said:
Must be my massive finger muscles... I wanted to redo them with a torque wrench incase I was a little heavy with the pressure... I'm a little OCD, sometimes thats not a good thing. :rolleyes:
Courtesy of the late Sheldon Brown
 
#8 ·
Nick09 said:
Thats probably what overtorqued the screw in the first place.... I may be a little heavy handed... Thats why I bought a torque wrench:idea:
Well, sometimes there are unintended consequences. At the lower end of their range, torque wrenches are not nearly as reliable as educated fingers.

One way to go after these small screws is to tighten the screw with one hand and rattle the gadget which the screw is supposed to hold with the other. When the gadget (in your case, the bottle cage) stops moving, give the screw another 1/4 turn and let that be good enough. Check after the first few rides and retighten just a tad if needed. If you get good at this, you can fix stuff on the road without a torque wrench. That's a valuable skill!
 
#9 ·
Well, it was a no go for the shop near me, which surprises me a bit, but it looks like I'm off to Lowes at somepoint. I don't think I am confident enough to do it myself though. I may wait until I am in Greenville. They have a few bike shops there.

wim, thannks for that advice, I'm defininately not going to use the torque wrench for the little stuff anymore, which then begs the question, why did I even get it? haha O well, it has to come in handy at some point.

Thanks to all for the advice!
 
#10 ·
Sometimes you can use a dremel or similar tool to cut a slot in the end of the screw and then use a screwdriver to remove it. I might even try to super glue or epoxy a small attachment to the end of the screw and after it sets, remove it...shouldn't be too tight without the head right? Just don't get messy and glue it in place.
 
#11 ·
Your problem is that it's going to be very difficult to avoid damage to the threaded insert, called a "rivnut" which will be made of fairly soft alloy. You did not say what the screw material is. If it's also alloy you stand a better chance with the methods above, but I'm not too hopeful.

You can try, but if the rivnut gets too badly damaged, an option is to install two new rivnuts, say about 1/2" away from the current ones.
 
#12 ·
Nick09 said:
wim, thannks for that advice, I'm defininately not going to use the torque wrench for the little stuff anymore, which then begs the question, why did I even get it?
Well, it can serve as a teaching tool of what certain torques feel like. Don't know your wrench, but it may be one that's better suited for high torques, like 40 Nm on crank bolts and such. Using a torque wrench like that on water bottle cage screws would be like what the Germans call Spatzen mit Kanonen schießen - - shooting sparrows with cannons. :)
 
#13 ·
where are you located?....any good jeweler can drill a hole in the center of a 3 or 4 mm screw and then you could get a small easy out into the hole. it really shouldn't be a big deal, I know i would have no problem getting it out... even if you can only run it IN, you should be able to get it out of the frame then
 
#15 ·
I am at Clemson, and the screw is made out of an alloy. Not sure of any jewelers around here, but it sounds like it is worth a try. The screw really isn't extremely small, looks like a regular 1/4 inch, but that is certainly too small for me to try and drill anything. My dad is coming down this weekend, and he said that we could run up to Greenville to see if someone at one of the bike stores up there could get it out.

@andulong: I was going to try to put a dot of super glue on the end of the broken head, and see if it would stick enough to get it unscrewed. Only problem with that is like you said, it could get messy and I could wind up gluing the screw in the hole.

Stupid idea with the superglue???? If i manage not to superglue the screw in, but fail to get it out, would it ruin the chances of a bike shop or a jeweler drilling a hole?
 
#16 ·
no super glue OK?
 
#24 ·
Sounds like a job for Duck Tape

Sounds like a job for Duck tape; forget about the screw, just duck tape the bottle cage to the frame; who cares how it looks. Are you that much of a bike snob that you will be concerned about everyone from RBR saying "look at Nick09, he has his water bottle cage duck taped to the frame". :rolleyes:

Am I also to understand that students at Clemson don't know how to screw? :blush2: Spend less time on your bike young man.
 
#25 ·
Tommy Walker said:
Am I also to understand that students at Clemson don't know how to screw? :blush2: Spend less time on your bike young man.
The problem was not the screwing... Just screwing to hard. :p

Turns out that all I needed was eyebrow pluckers... Felt stupid as the guy at the shop took it out in two seconds.
 
#26 ·
You mean he just grabbed it with tweezers? You mean enough of the screw was sticking out to be grabbed? YOU NEVER SAID THAT! You said it "snapped off in the hole," implying that the break was at or below the surface of the nut.

I (and plenty of others) would have advised you to try to grab it with needle-nose pliers.

If you're not going to be precise with your descriptions, you're required to post clear pictures ;-)

Glad it got worked out with no damage. Enjoy the bike.
 
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