Ruined chainset thread. Help me back from this

petemadoc
petemadoc Posts: 2,331
edited June 2014 in Workshop
A moment of stupidity has caused the following problem, is there a way out of this?
14384451356_50b86cf757_k.jpg

The non drive sideu has a central bolt which is used to set the bearings so the torque is only 1.5N. I've stupidly overtorqued it which has resulted in the Allen bolt rounding off and being unusable.

So now it is too tight and I can't loosen it. How do I recover this?

Comments

  • nicklouse
    nicklouse Posts: 50,675
    You only adjust it after slackening off the two pinch bolts.

    So order up a new one. Slacken off the pinch bolts jam something into the old bolt and undo.

    Fit new bolt adjust. Tighten up pinch bolts.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • paul_onabike
    paul_onabike Posts: 194
    As the part is now only fit for the bin you can try either hammering a slightly larger allen key or torx bit into the damaged recess. Or you could do the same with a flat bladed screwdriver if you have one of suitable size. Before you do either though - you must undo the crank arm clamp bolts if they have been tightened. There are other ways of removing the adjuster, but try these first. It just depends what tools you have available.
  • jackc6549
    jackc6549 Posts: 30
    Last time I fitted some hollow tech II cranks (didn't have the little plastic tool), I found the jaw ends of a pair of pliers was a perfect fit to tighten the nylon bolt. Not sure of the size of the Fsa bolt, but might be worth trying if the above mentioned Allen key method doesn't work.
  • craker
    craker Posts: 1,739
    Those Mega-Exo cranks are doing my nut. I bought a torque wrench to do it properly - that bolt you've mangled is only torqued at 1.5 Nm which is barely more than finger tight. First ride after tightening... it's come off again. I've reached for my spare parts bin and pulled out an old Deore square taper crankset, think I'll have that on instead.

    On the other hand, the bottom bracket on my commuter is mega-exo and has survived a good few thousand miles and a couple of winters despite the bad press they get.

    My other FSA crankset I tightened that bolt to about 10 Nm after pouring a load of threadlock on it. So far so good (1 week ..)
  • petemadoc
    petemadoc Posts: 2,331
    I shall try your suggestions thanks peeps.
  • petemadoc
    petemadoc Posts: 2,331
    Quick thanks for your help peeps. The screwdriver method came up trumps in the end.

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