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Discussion in 'Maintenance and Servicing' started by christophe, Oct 1, 2012.

  1. :nopity:

    Hi Guys,

    Messed up a little :(

    After a day of thinking we where f'ing awesome and ready to man the pit team for stoner (read: changed over the tyres manually) I managed to snap a bolt when reattaching the disk onto the tyre.

    Not a huge issue right?

    My mate who "has done this before" assured me he could drill the bolt out.

    Please refer to the attached pic to see the result. In short - the new hole is a mess and bigger than the old tread.

    How the hell do I fix this?

    I desperately need my bike back on the road (P's test in two weeks).

    Any help would be very very much appreciated.



    Attached Files:

  2. Long term fix - drill and tap the hole to accept a slightly largely diameter bolt.
    Short term fix - do you really need all those bolts to hold the rotor in place, and would anyone notice if one was missing.....
  3. Is there room for a nut at the back?
    Sorry i dont know the layout you have.
    If theres room a longer bolt and nut is
    Well not as easy as leaving one of.
    You could glue a " show only " bolt
    Head on ....
    Dodgy as...

    Helicoil cud be the go but JD i recon
    Is on the money to simply tap bigger.
    Its not very hard to do on alloy.
    Tip make sure new bolt is a soft mild
    Steel - there is markings but basically
    Silver in colour ...
  4. Why did you take the disc off ?

    Your reality is-the wheel is farked.
    • Like Like x 2
  5. another idea would be to look for a good rim at the wreckers. you never know if they have your bike out there. and since you have already messed that one up, you should pretty well know what you are doing this time around.
  6. go to superbarnrepco and get a bolt removal kit.

    it's basically a tapered screw with a reverse thread... you drill a small pilot hole then screw this into it, as it goes in it tightens and as it's reverse threaded as it tightens it forces the bolt to undo.

    otherwise take the wheel to a mechanic, they pretty much ALWAYS have these kits, and get them to do it. might cost you a beer or two.

    eidt: didn't see your mates handywork. go to a wreckers and try for a new wheel.... otherwise sleeve or larger bolt is the only way...
    • Like Like x 1
  7. With mates like that, who needs enemies?

    A mate of mine destroyed the swing arm on another mate's dirt bike trying to undo a bolt with a mallet and a cold chisel because he didn't have the right sized socket and tried to be helpful. Gotta love it.

    I'd be taking it to the local bike shop / mechanic at this point, let them have a good laugh at you, then see if they can resize the hole to take a bigger bolt, or hook you up with a better solution.
  8. Should be an easy fix. Go to one of the local stores and get yourself a tap and die set. Simply tap a new thread into the hole, one big enough to repair the damage your mate has done. Then, just find a bolt in your shed that will fit the new thread! Either that or buy a new bolt from bunnings or what ever.

    Either that or get a mechanic to do it. Should realistically take 10 minutes.
  9. Just make sure you get it fixed properly.
    Don't risk anything less or take any shortcuts, theres just too much load on the rotor to risk it.
    Unless you really know what you're doing, its always best to try and stick with the original design specs.
    Even if that means a replacement rear wheel...
  10. Tap and die set or get a new rim from the wreckers?
  11. Hey geniuses,if he taps it to the next size up and uses a bigger bolt-the bigger bolt wont fit through the hole in the disc.What then ? Drill out the disc.
    Stop talking of things you have no idea about-you are dangerous.
    • Like Like x 4
  12. I thought that was understood, but apart from ruining an otherwise perfectly good disc (assuming the op's mate hasn't already), what's dangerous about it?

    First thing that comes to mind is that replacing the rim in future would mean replacing the disc as well, but otherwise what problems are there with the idea in theory?

    Would it be unsafe? Technically impossible? Too expensive?
  13. the wheel and disc would become unballanced.

    unbalanced wheel will give you shudders, this can sometimes be amended by weighting, but that is ment to counter balance for imperfections in the tyre.

    an unbalanced disc on the other hand, could be fairly dangerous.

    not to mention you are compromising the integrity of the wheel. maybe not greatly, but every little weak spot counts
    • Like Like x 1
  14. The best fix for this is time-sert.

    It is like a helicoil, but is case hardened steel, and a complete sleeve. It will allow you to use the original size bolt also, avoiding balance issues.

    Look them up. Time-sert.
  15. take the thing and see if it can be Heleicoiled , thats basically where the hole
    is tapped bigger and a thread insert is screwed in making it back to orginal.

    its yoru best chance and maybe only , and worth the ask, the photo isnt good enough,
    the main issue is going to be - how much damage as there is only a small tolerance in size. and accuracy of location - this is a precise location and a few thou will be a fail.
    lots of workshops - genaral mechanics etc will have a basic helicoil set on hand.
    it wont be cheap because of "pain in arse factor" and the mechanic if smart will say something like - no guarantee if it works or not , because thats life - ask derryn hinch.
  16. o fark vtr soz mate i didnt read your post ,
    i dont know what time inserts are - ive been out the game quite a while.

    just google they look much better than helicoil - they were a fiddly idea but still could save ya neck
    when in deep.

    nice tip vtr i would imagine most places wouldnt have helicoils anymore with those insert things.
  17. Wow, I must admit I'm surprised to hear that making what seems to be such a tiny modification to the disc could affect the balance enough to be even a minor issue.

    The amount of steel in the hole should be the same, so I figured the only difference would have been a miniscule increase in the size of the bolt head. I was thinking a few grams at most, and it really didn't seem like enough to cause noticeable problems, especially so close to the hub, on a part that's bolted solidly to something else, not swinging around unsupported like the outside edge of the rotor.

    The physics seems wrong to be honest. Reminds me of that mythbusters episode where they taped a postage stamp to a helicopter blade and it did SFA.

    Having said all that, what the hell would I know? I'm just speculating. I assume you blokes have experience/evidence to support what you're saying, so I'll take your word for it.
  18. People break bolts all the time in worse places, it's just a process to follow at the end of the day, think of it like an unstoppable steamroller if you stick with the process. If at any stage if you are uncomfortable or don't think you can do it properly, step away from the bike. It takes a lot of guts to do that sometimes but it's better than persisting on and hoping for a solution to emerge.
    1) Remove sheared bolt via all methods available, if you can't do it, get someone who can to do it for you. There's plenty of ways to go about this as listed above, from DIY shadetree techniques (not listed above) to asking a professional (& I didnt mean a franchised bikeshop), appropriate heat, impact, penetrants, bolt removal kits as mentioned above which has a sticky from memory.
    2) Once removed, clean threads and assess, there may be enough material to hold the required torque. Apply judgement and compare to known minimum number of a threads a fastener of "X" size needs to hold a certain torque. Failing that...
    3) Replace threads, timesert or helicoil. Failing that...
    4) Replace wheel and punch friend in face for his kind work. And/or failing that
    5) Borrow friend's bike in 2 weeks time
    6) Regardless replace that bolt with correct size, pitch and grade, and consider doing all at this stage as you don't want to go through this again upon reinstallation with the other 5 old bolts.
    7) Get a copy of the service manual, read it, and invest in a torque wrench & med strength (blue) loctite/permatex
    • Like Like x 2
  19. Helicoil it
  20. Helicoil should do the job much better than making a larger threaded hole. I rode around with a bolt missing for a week when I snapped the head of a disc bolt while removing it. I don't condone it, but I had not issues.