I'm trying to take the reflector off of some old French track pedals but can't remove one of the bolts holding the reflector on because the bolt holding the reflector onto the pedal rotates with its nut and it has a smooth, round head with no screw drive at all, so I can't find a way of producing any torque to remove the nut by holding the bolt in place. I even tried "clamping" the bolt head with some pliers by putting the head of the bolt against one jaw of the pliers while the other jaw was against the inside of the pedal itself, but the bolt still rotated freely even when applying as much pressure as possible with the pliers.

Pedal inside Pedal outside

Additionally, when I removed the plastic reflector from its metal housing (which I'm trying to remove), a rusty thin strip of metal fell out (highlighted in green in the photo); Is this possibly some clue to removing the bolt?-- I had no problems removing the bolts on the other pedal, but I'm unsure of the internal "configuration" of the reflector, i.e. if the other reflectors on the other pedal also have this weird metal strip thing. However, I'm reluctant to remove the other reflectors to check because whenever I take anything off of this bike, there is a very good chance that it'll break in the process and I won't be able to get it back on.

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    I think you need to slide the bolt left or right enough that the square underside engages in the slots. As currently positioned it's in the space between crossing slots and so can spin around. May 15, 2016 at 1:20
  • I guess you want to save the bolt for authenticity? If not, attack it with a dremel and cutoff wheel. Consider adding some penetrating oil to the threads and leave it to sit overnight. Another option is to use a nut splitter to cleave the nut in two, and hopefully leave the bolt as-is. You'd need a new nut.
    – Criggie
    May 15, 2016 at 2:11
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    @Criggie: I guess you want to save the bolt for authenticity? > No, I just don't have stuff like a dremel or cutoff wheel... but some oil might actually be possible. May 15, 2016 at 7:31
  • @DanielRHicks: I took a look at the other bolt and tried putting it back on and it does in fact "lock" into the slot so it doesn't spin around, but the bolt in question doesn't do that; It seems to be stripped. I suppose the only option might be to cut it somehow? May 15, 2016 at 8:51
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    My point is that it's positioned in the crossing point between the horizontal slot and the vertical one. You need to slide it over to engage in the slot. May 15, 2016 at 12:03

2 Answers 2


I expect that when you try to turn the nut you'll rind that the round bolt head is eccentric on the bolt. Side on it looks like the sketch below, and means the bolt won't rotate once it's in the hole.

eccentric head bolt

This is quite old school, and they're very easy to manufacture with only fairly basic hand tools. Imagine trying to cut a hexagonal hole into a pedal using only a drill and file.

  • So if OP cuts some kind of square blocker with a round hole in the middle and straight edges that will sit between where the metal folds out, it should lock up the round head enough to undo the nut on the other side? Cunning!
    – Criggie
    May 15, 2016 at 7:02
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    I checked the other bolt (which I did manage to remove) and the head is unfortunately not eccentric. However, I did see that it has a small unthreaded part underneath the head which has two opposing sides which are parallel and while the other two sides are rounded; Might there be something thin enough to stick between the pedal and the bolt head which can be used to hold these two sides? May 15, 2016 at 7:29
  • Good idea - how about some combination of tongues from a spark plug gap gauge, something like bimmerboost.com/… Or even a well-aimed small flathead screwdriver might be all it takes.
    – Criggie
    May 15, 2016 at 7:59
  • The bolt appears to be stripped because it's not staying in place like the other ones do... May 15, 2016 at 8:52
  • Then its knackered. Split the nut or cut it off, and replace with a new one.
    – Criggie
    May 15, 2016 at 11:20

You might succeed with a screw extractor. If you can drill into the head, this will give you purchase. It depends on how hard the bolt head is. I recommend center punching before drilling. Some penetrating oil on the threads might help as well.

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