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So I stupidly rounded a couple of my inner chainring fixing bolts trying to tighten them up to correct torque. I rushed the job and did it on the floor instead of a workstand as I should have to get the right angle.

 

Anyway I got myself some replacement bolts as I cant bare to look at what I have done. I am actually disgusted with myself. I have not tried yet but any home tips for getting them out without using a extractor kit or LBS? I feel like there is a one shot chance of getting them out before they are totally rounded 

 

Thanks 

21 comments

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Canyon48 [1102 posts] 5 months ago
3 likes

Use a torx key.

It must be slightly bigger than the diameter of the whole and may need a few taps to wedge it in place.

That's how I've removed rounded hex's previously.

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shawdogg [20 posts] 5 months ago
0 likes

Did EXACTLY the same thing this morning to one of mine, going to try torx key tonight as had success with method on a previously rounded bolt I had though think it will be a little harder to tap in this time being on the chainring. Good luck!

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Canyon48 [1102 posts] 5 months ago
1 like

If it's a very stuck chainring bolt (as many are), soaking them in a decent penetrating oil will probably help somewhat.

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Shades [434 posts] 5 months ago
0 likes

Easyout with a drill?  Had a similar situation with some siezed bolts securing mudguards and the pannier.  Slightly corroded bolts stripped immediately; had to get pretty brutal with the easyout and a drill to get them to move.  Even destroyed one of the Easyouts in the process.

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SpikeBike [125 posts] 5 months ago
0 likes

Sorry I should have said. Yes they are Torx bolts. I had a creak so was doing the make sure nothing is loose check. They apparently should be 12Nm-14Nm when dry so I went for 10Nm as a check. Its a new groupset so no seizing. It is defo all my fault.

I thought maybe a thin rag with the torx or a flat head screwdriver?

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Canyon48 [1102 posts] 5 months ago
1 like
SpikeBike wrote:

Sorry I should have said. Yes they are Torx bolts. I had a creak so was doing the make sure nothing is loose check. They apparently should be 12Nm-14Nm when dry so I went for 10Nm as a check. Its a new groupset so no seizing. It is defo all my fault. I thought maybe a thin rag with the torx or a flat head screwdriver?

Oooh, that might be a bit more difficult then.

I've had good success with putting a rubber band over the end of the tool before trying to undo a stripped bolt.

Worst case, get a dremel and cut a slit in the bolt, into which you can get a flat head.

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IanMunro [48 posts] 5 months ago
1 like

Assuming they aren't made of cheese/ali 12-14 sounds pretty standard to me. What makes you think that's ridiculously high?

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StraelGuy [1586 posts] 5 months ago
0 likes

Correct, ft/lb values are approx 3/4 of nm ie 20 nm is approx 15 ft/lbs.

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Innerlube [47 posts] 5 months ago
1 like
Canyon48 wrote:
SpikeBike wrote:

Sorry I should have said. Yes they are Torx bolts. I had a creak so was doing the make sure nothing is loose check. They apparently should be 12Nm-14Nm when dry so I went for 10Nm as a check. Its a new groupset so no seizing. It is defo all my fault. I thought maybe a thin rag with the torx or a flat head screwdriver?

Oooh, that might be a bit more difficult then.

I've had good success with putting a rubber band over the end of the tool before trying to undo a stripped bolt.

Worst case, get a dremel and cut a slit in the bolt, into which you can get a flat head.

Most of these bolts are recessed, but I’ve come across some which protrude enough to cut a cross slot with a cheap hacksaw, then use a flat head driver to undo. Never bought a dremel but the old tv ads would suggest they would be ideal for the job for the more usual recessed bolts!

 

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fukawitribe [2601 posts] 5 months ago
1 like

5-10Nm for alloy bolts and 8-12Nm for steel would seem pretty normal - Campag 11s is 8Nm dry apparently (bike.owner will correct if wrong), Shimano was 8-10Nm IIRC but just had a quick look some of the newer stuff seems really high, e.g. T30s on the Dura Ace cranks is 12-16Nm (presumably dry). The FSA K-Force L and Omegas from my Wilier are 12Nm wet, no idea about the others.

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SpikeBike [125 posts] 5 months ago
1 like

12-16Nm say the specs. I bothered to read it before I went to do it. I am just an idiot with fat hands

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kil0ran [1177 posts] 5 months ago
1 like

Now that they're in why do you want to remove them? Chalk it up to experience and unless it's Red or Dura-Ace just replace the crankset when the rings wear out.

If you do need to remove it if you haven't done so already take the crankset off the bike, try bashing a larger-sized torx into the hole, then clamp the tool in a vice and use the crankarm as a lever.

Are you sure the bolt isn't cross-threaded? I've managed to cross thread a couple in my time (the recurring theme here appears to be trying to do it on the bike rather than removing the crankset)

You'll need to be slightly careful as the threads on the chainrings aren't particularly deep.

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SpikeBike [125 posts] 5 months ago
1 like
kil0ran wrote:

Now that they're in why do you want to remove them? Chalk it up to experience and unless it's Red or Dura-Ace just replace the crankset when the rings wear out.

If you do need to remove it if you haven't done so already take the crankset off the bike, try bashing a larger-sized torx into the hole, then clamp the tool in a vice and use the crankarm as a lever.

Are you sure the bolt isn't cross-threaded? I've managed to cross thread a couple in my time (the recurring theme here appears to be trying to do it on the bike rather than removing the crankset)

You'll need to be slightly careful as the threads on the chainrings aren't particularly deep.

Yeah they don't need to come out now it's just that it is pretty new (<100miles) and it irritates me. Maybe I should just chalk it up to experience? I was hoping for an easy fix but might make it worse.

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kil0ran [1177 posts] 5 months ago
1 like
SpikeBike wrote:
kil0ran wrote:

Now that they're in why do you want to remove them? Chalk it up to experience and unless it's Red or Dura-Ace just replace the crankset when the rings wear out.

If you do need to remove it if you haven't done so already take the crankset off the bike, try bashing a larger-sized torx into the hole, then clamp the tool in a vice and use the crankarm as a lever.

Are you sure the bolt isn't cross-threaded? I've managed to cross thread a couple in my time (the recurring theme here appears to be trying to do it on the bike rather than removing the crankset)

You'll need to be slightly careful as the threads on the chainrings aren't particularly deep.

Yeah they don't need to come out now it's just that it is pretty new (<100miles) and it irritates me. Maybe I should just chalk it up to experience? I was hoping for an easy fix but might make it worse.

I know that feeling. I'm amazed that they work loose, and they're worth checking reasonably frequently. Last time I did it I had one missing and another very loose - unsurprisingly there was quite a bit of creaking.

If you do have a go at removing it the big advantage of clamping the torx key in a vice is that you can push down hard on the chainring (cover teeth with a rag) and persuade the bolt loose with the crank arm. Should stop the tool from slipping. 

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shawdogg [20 posts] 5 months ago
1 like

Success! Managed to hammer torx key in and remove the offending bolt this morning. Replaced all bolts now and ordered Park tools 5mm hex just to be safe. 

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DaSy [853 posts] 5 months ago
1 like

In my experience, it is often the case that the Torx driver tip was not fully inserted into the head that causes it to strip, but that it generally tends to then strip just the upper portion of the head splines.

I would take the crank-set off the bike to get better access, then insert the T30 driver carefully into the head and gently wiggle it and push it down, to try and get it to seat deep into the head. Chances are that there are some good splines deeper into the head. Once it feels like it is as deep as it will go, tap the driver gently with something like a big screwdriver etc, just to get a good seat, then gently and smoothly attempt to undo the bolt.

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Canyon48 [1102 posts] 5 months ago
1 like
shawdogg wrote:

Success! Managed to hammer torx key in and remove the offending bolt this morning. Replaced all bolts now and ordered Park tools 5mm hex just to be safe. 

Good news!

Lesson learnt maybe? We've all done it 

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DaSy [853 posts] 5 months ago
0 likes

Good news, also I wasn't just stating the bleedin' obvious above, I must have been typing whilst you were wrenching!

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SpikeBike [125 posts] 5 months ago
1 like
shawdogg wrote:

Success! Managed to hammer torx key in and remove the offending bolt this morning. Replaced all bolts now and ordered Park tools 5mm hex just to be safe. 

 

I want picture to see if mine is worse lol!

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muraii [1 post] 3 months ago
0 likes

This is an old thread and I'm new here but I wanted to chime in and say I have done something similar but more particularly egregious. I utterly destroyed my h-limit screw head on a ~2010 Campy Record rear derailleur. I have no idea how it became seized other than poor maintenance (it's probably not been turned in at least a couple of years).

 

I started out with a decent Philips-head screwdriver, and when that did nothing I moved up to a better screwdriver on which I could exert more torque, which properly munged the screw head. Then I used some penetrating lubricant and a hacksaw to cut a flathead notch, and thereafter succeeded only in doing more damage to the poor thing. I found a small (#1) screw extractor bit and went at this m4 screw with decided passion, even resorting to using a my smallest bit to help create something the extractor bit would bite.

 

I eventually resorted to going to my LBS who promptly just broke the top of the screw off and gave me some well-meaning-but-probably-bad counsel about the fact that the limit-screw spring was exposed therefore the whole RD was toast. So my RD sits on my basement workbench waiting for me to probably disassemble it and pry the screw body out without damaging the whole thing. Failing that, I'm researching a replacement I can afford, which will not likely be another Record for US$600 but could be a much less-expensive Veloce 10s.

 

It'll all have been worth it. Before this debacle I didn't realize how poor I'd been maintaining my bike, and now through several forums and YouTube videos and the Branford Bikes knowledge base and other assorted online sources have demystified the proper maintenance and composition of bicycles.

 

Hi from the States and thanks for not being jerks like on another bike forum.  1

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DaSy [853 posts] 3 months ago
0 likes
muraii wrote:

So my RD sits on my basement workbench waiting for me to probably disassemble it and pry the screw body out without damaging the whole thing. Failing that, I'm researching a replacement I can afford, which will not likely be another Record for US$600 but could be a much less-expensive Veloce 10s.

 

Have you tried removing the parallelogram plate (that has the limit screws on it) from the deraileur? From memory, it is just a couple of coach screws at either end. Then you can access the shaft of the limit screw from the rear. A set of mole grips on the screw shaft and rotate the plate, after a liberal application of penetrating oil, should get it out. I have replaced the whole parellelogram plate on a couple of Campy Record rear deraileurs which is very straightforward. I think the screws are available as a spare part from Campag.

 

Edit to say, here's a link to the screws on their own in the US http://www.bikeman.com/DP9898.html