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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 

19 comments

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Canyon48 [990 posts] 1 month ago
4 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] 1 month 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 [990 posts] 1 month 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 [387 posts] 1 month 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 [96 posts] 1 month 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 [990 posts] 1 month 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 [44 posts] 1 month 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 [1442 posts] 1 month 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 [43 posts] 1 month 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 [2446 posts] 1 month 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 [96 posts] 1 month 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 [923 posts] 1 month 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 [96 posts] 1 month 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 [923 posts] 1 month 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] 1 month 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 [824 posts] 1 month 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 [990 posts] 1 month 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 [824 posts] 1 month 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 [96 posts] 1 month 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!