Page 1 of 2 12 LastLast
Results 1 to 10 of 14

Thread: Rotor Bolts

  1. #1
    2 YEAR PREMIER MEMBER RickS1K's Avatar
    Join Date
    Sep 2012
    Location
    Surrey
    Posts
    522
    Thanked: 151

    Rotor Bolts

    I need to replace my rotors as they've done 20k miles. I know most manufacturers say the bolts have to be changed every time you remove them. I've had them off once when I had a ding on the wheel repaired, and I reused them. The bolts look OK to me - is that enough, or should I change them this time?

    Cheers

    R

  2. #2
    Standard Member DrIoannis's Avatar
    Join Date
    May 2016
    Posts
    305
    Thanked: 62

    Re: Rotor Bolts

    The manual say, change them. What I dis is bought a set of titanium bolts and reuse them with proper torque and thread lock.


  3. #3
    2 YEAR PREMIER MEMBER JamieMac's Avatar
    Join Date
    Apr 2017
    Posts
    798
    Thanked: 357

    Re: Rotor Bolts

    The reason they tell you to replace them is the dry thread lock only works once. There’s nothing wrong with the bolts themselves being used again and again if you apply your own thread lock.

  4. #4
    2 YEAR PREMIER MEMBER MrSmooth's Avatar
    Join Date
    May 2018
    Location
    Camberley
    Riding
    S1000RR 18 Blue
    Posts
    168
    Thanked: 81

    Re: Rotor Bolts

    Quote Originally Posted by RickS1K View Post
    I need to replace my rotors as they've done 20k miles. I know most manufacturers say the bolts have to be changed every time you remove them. I've had them off once when I had a ding on the wheel repaired, and I reused them. The bolts look OK to me - is that enough, or should I change them this time?

    Cheers

    R
    Be careful, the disks/rotors experience significant heat cycles and with the threadlock the bolts might be tough to start to undo them. Ensure you have cleaned the bolt heads and that the tool you use has crisp edges. Keep everything straight and consider using a breaker bar to extend the torque on the tool and turn it gently to start it off. Also consider lifting the wheel rims onto long flat blocks of wood so you don't damage the wheel edges or a new disk/rotor when you fit the new ones. I speak from experience trying to remove some disks/rotors from another bike, had to drill out a couple of the bolts which I had rounded.

  5. The Following User Says Thank You to MrSmooth For This Useful Post:


  6. #5
    2 YEAR PREMIER MEMBER JamieMac's Avatar
    Join Date
    Apr 2017
    Posts
    798
    Thanked: 357

    Re: Rotor Bolts

    Undoing any bolt .... heat, heat and more heat around the area the bolt goes into. Hot air gun better than naked flame.

    .... and this will sound strange but partly do the bolt up little tighter as this will most likely break any corrosion instead of snapping the bolt, then undo.

    As Mr Smooth says make sure the tool fits. If the allen head is loose, use a bit of valve grinding paste in the bolt head to take up any play. They used to even do that on Concorde.

  7. The Following User Says Thank You to JamieMac For This Useful Post:


  8. #6
    2 YEAR PREMIER MEMBER RickS1K's Avatar
    Join Date
    Sep 2012
    Location
    Surrey
    Posts
    522
    Thanked: 151

    Re: Rotor Bolts

    So after reading all this and inspecting my rotor bolts I decided that I would replace them after all. I took them out last night (using a heat gun, cheers JamieMac) and they all came out without any issue whatsoever. Tonight I tried to fit the new rotors and new bolts and there's a problem. 9 bolts go in no problem at all, and one doesn't. I get it halfway down, then it doesn't feel like it wants to go any further. I didn't force it, just took it out and tried a few things:
    1. Cleaned the screwhole with wd40 and a cotton bud to clear out any debris I missed last night
    2. Tried different bolts - new and old - everything stops in the same place..

    So, it feels like it has cross threaded... I don't want to force it down....

    Thoughts?
    Last edited by RickS1K; 13th May 2021 at 08:19 PM.

  9. #7
    2 YEAR PREMIER MEMBER JamieMac's Avatar
    Join Date
    Apr 2017
    Posts
    798
    Thanked: 357

    Re: Rotor Bolts

    Run a ‘tap’ of the correct size down the thread in the wheel to clean out the thread. A tap and die set is cheap and worth having. J

  10. #8
    2 YEAR PREMIER MEMBER RickS1K's Avatar
    Join Date
    Sep 2012
    Location
    Surrey
    Posts
    522
    Thanked: 151

    Re: Rotor Bolts

    Like this https://www.toolstation.com/draper-tap-die-set/p10128? The probolt website says the bolts have an 8mm diameter.

  11. #9
    2 YEAR PREMIER MEMBER JamieMac's Avatar
    Join Date
    Apr 2017
    Posts
    798
    Thanked: 357

    Re: Rotor Bolts

    Check the pitch as well. An M8 bolt can like all bolts have multiple pitch. Probolt do a hand bolt tool which allows you to check size, pitch, length.

  12. #10
    2 YEAR PREMIER MEMBER preynol1's Avatar
    Join Date
    May 2017
    Location
    Hockley Essex
    Posts
    374
    Thanked: 241

    Re: Rotor Bolts

    If it’s the thread pitch on the bolt you would identify it after trying different bolts from the new batch. Have you done this?
    It the batch of bolts thread was wrong then the same issue would be seen in other holes.

    Overlay a new and old bolt the threads should interlock. If they done thread is different.
    Also measure bolt shoulder.

    Try the new bolts with an old disc. If it works it’s the disc hole dia or hole pitch.
    If it’s the same retap the holes gently.

    Couple of things, did you run down all bolts fully as you assembled or partially assembled / left loose before adding the final bolt?
    Is the issue common on both discs?


    Sent from my iPhone using Tapatalk

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •