Rounded/stripped bolts - tips please.......

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.

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

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.

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. 

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.

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.

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

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

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.

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

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!

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.