Rounded off rotor bolt – HELP!

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  • Rounded off rotor bolt – HELP!
  • neilwheel
    Member

    1. If it’s a hex head, try a larger size torx bit, might need a tap with a hammer to get it seated.

    2. Then try cutting a slot in the head for a flat screwdiver.

    3. If that fails cut the head off and get some mole grips on the bit that’s left.

    You should be fine about the torque settings, just double check after first ride.

    doncorleoni
    Member

    As above…. But I would just leave it if you have installed and deal with it later. They are made of cheese so worst case just drill the head off and remove the remaining bolt with mole grips.

    There used to be a chap I rode with who only ran 3 bolts to save weight 🙂 and common for these xc weight weeny types. Crazy.

    chopchop
    Member

    Use a dremel or similar tool with a disc attachment, cut a groove big enough for the heftiest screwdriver you have then apply lots of downwards pressure whilst you use the screwdriver to take the bolt out.
    I should imagine you’d be fine replacing it without torquing them all up again.

    Edit, beaten to it

    Premier Icon Tracey
    Subscriber

    Angle grinder and a big flathead screwdriver always works for us

    shermer75
    Member

    If it’s the last one can you wriggle the rotor?

    PJay
    Member

    Tried wiggling the rotor but it catches unfortunately. New wheels so I don’t want to damage anything!

    Premier Icon scotroutes
    Subscriber

    If all else fails, grind/drill off the bolt head that’s damaged.
    Then remove the other five bolts and the rotor will come off.
    You’ll then have a little stub of the failed bolt (the thickness of the rotor). Grab this with a pair of molgrips and twist to remove.

    PJay
    Member

    I’ve just transferred a pair of rotors from my 26er to my 29er wheels. All went well except for some reason one of the bolts on the rear rotor (the last I was doing) rounded off and I can’t get it out. I’ve got a replacement bolt but how do I get out the other bolt?

    Also if I do get it out is it okay just to tighten in the new bolt as all the others are up to torque and were tightened alternately, or do I need to take them all out and start again?

    PJay
    Member

    Finally got there hacksawing a rather off centre slot for a screwdriver (had to be a tad careful not to hack the rotor or hub). Hopefully no harm done, except to my nerves.

    I’m starting to see the attraction of Centrelock!

    PJay
    Member

    Argh! Just had another one go refitting it! Fortunately I managed to back if off. Perhaps I need to consider rotor bolt a ‘use once’ affair!

    The torque settings on the SRAM Centreline rotor says to torque the bolts to 6.2 Nm which seems a tad high considering some Avids I had recommended 2-3Nm, can I torque them a little lower?

    Premier Icon jam bo
    Subscriber

    Best tip I got from here. Tighten a drill chuck onto the outside of the bolt. Comes out dead easy.

    Premier Icon bramblesummer
    Subscriber

    Steve Peat raced for years without all the rotor bolts.

    Is your allen key in good condition? If you’ve damaged 2 now then it’s likely worn. Worn allen keys will damage bolts very easily.

    Best replacement bolts around are the Hope ones. Nice deep torx heads and good quality bolt. I’ve actually had a torx bit break before the hope bolt. Lots available from everywhere, only a few pounds, and can be fitted to any rotor or hub.

    http://www.chainreactioncycles.com/hope-steel-disc-rotor-bolts/rp-prod9950

    PJay
    Member

    I’ll probably get some of those Hope bolts as spares for the next time I need to fit a rotor!

    Premier Icon Poopscoop
    Subscriber

    jam bo – Member
    Best tip I got from here. Tighten a drill chuck onto the outside of the bolt. Comes out dead easy.

    That’s new to me, will try that if ever necessary!

    swdan
    Member

    Yeah, could have done with that too a few months ago. Tried everything, large torx bit, cutting a slot in it, scree extractor. In the end did as above and drilled the head off, removed the rotor then used a pair of molgrip to remove the sticky out bit. Was pretty easy after I wasted two evenings on all the other methods!

    demelitia
    Member

    Something to consider for future use are the Wera Hex Plus and Torx L-keys. Very well machined, especially the hex keys which have some patented geometry to allow either more force to be applied with much less chance of rounding the head of fasteners.

    They aren’t cheap but they’re great value I think.

    shermer75
    Member

    I’m starting to see the attraction of Centrelock!

    I am a massive fan of the centrelock! 🙂

    Premier Icon Speshpaul
    Subscriber

    Chase the nasty blue thread lock off the new bolts before you use them. Use a tiny dab of copper slip, and the correct torque.

    stoddys
    Member

    Glad your sorted, your heart sinks, well mine did. I had 3 ,very embarrassing.
    I went down the easy out route. Drilled a hole down the middle, and used the easy out and they all undid fine.

    Might help some one in the future.

    PJay
    Member

    The threadlock is pretty tacky and to be fair I think that the bolts have been used 3 or so times before (and have had a rough time out in all weathers); I was probably asking for trouble.

    I think that from now on it’ll be new bolts each time.

    Premier Icon jonnyboi
    Subscriber

    rotor bolts can be reused plenty of times with no issues. I’d be looking at the quality of your tools first.

    Premier Icon leffeboy
    Subscriber

    Allen keys like screwdrivers do need replacing. Throw the old ones out as well. The Wera stuff is lovely

    Premier Icon teamslug
    Subscriber

    Might not have worked with your situation but a good tip I picked up when working with rounded or damaged hex or torq bolts is an elastic band or piece of inner tube stretched over the end of your tool

    teasel
    Member

    Scotscrote » Grab this with a pair of molgrips

    There’s two of the buggers…?!

    Saints preserve us.

    ChunkyMTB
    Member

    elastic band or piece of inner tube stretched over the end of your tool

    😯

    Kinky

    It might not be tool……it might be the bolt…..or the size choice?

    I think they usually T25….but a T20 will work just about…..perhaps some errors occur when T20’s are used accidentally!! 😉

    Premier Icon gofasterstripes
    Subscriber

    Be careful with using grease on the threads- approx 90% of bolt torque is lost in friction, so reducing it with grease can lead to proportionally large increases in total torque: you can bugger something up badly.

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