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Thread: Rotor bolts?

  1. #1
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    Rotor bolts?

    OK. I give up. I have tried searches. I have called LBS. No one has the answer. It seems like some bike nerd out there should know this off the top of the head. And I am getting slightly frustrated.

    Question:
    I have a disc hub with no bolts. What do I ask for at the hardware store to get replacement bolts???

    I prefer socket head stainless if possible, because torx is dumbness. But I just need to know pitch basically. I am guessing they are M5.

    Before you even say it:
    No I did not take the wheel to the store yet....
    I am a commuter and don't have a car, and would rather get the information and then have the answer rather than carrying my wheel all over town like a goobenstein.


    Thanks brake gurus for any and all help.
    no chain no gain.

  2. #2
    um hmmm
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    Why wouldn't the bike shops you called just sell them to you? They must stock them..

  3. #3
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    M5x.8x10mm

  4. #4
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    m5 x 10

  5. #5
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    An issue to consider with rotor bolts is that if you get tall heads, then they will rub on the fork leg. Rotor bolts have generally thin heads so they have clearance. That is another reason for the torx head, as it strips much less easy than allen key
    Rimmer - "There's an old human saying - if you talk garbage, expect pain"

  6. #6
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    Quote Originally Posted by AlexRandall
    An issue to consider with rotor bolts is that if you get tall heads, then they will rub on the fork leg. Rotor bolts have generally thin heads so they have clearance. That is another reason for the torx head, as it strips much less easy than allen key
    Yup, a socket head is likely to rub on any suspension fork and even some rigid forks. That is the reason button heads are used. Then the socket (usually 3mm if hex) is shallow and easily stripped, hence the common use of Torx. Stripping bolt heads is dumbness
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  7. #7
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    We have a winner!

    Quote Originally Posted by gmcttr
    M5x.8x10mm
    Thank you for providing me with the correct information. Your input is very appreciated.
    no chain no gain.

  8. #8
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    I would think....

    Quote Originally Posted by 10speedbiopacefreewheel
    OK. I give up. I have tried searches. I have called LBS. No one has the answer. It seems like some bike nerd out there should know this off the top of the head. And I am getting slightly frustrated.

    Question:
    I have a disc hub with no bolts. What do I ask for at the hardware store to get replacement bolts???

    I prefer socket head stainless if possible, because torx is dumbness. But I just need to know pitch basically. I am guessing they are M5.

    Before you even say it:
    No I did not take the wheel to the store yet....
    I am a commuter and don't have a car, and would rather get the information and then have the answer rather than carrying my wheel all over town like a goobenstein.


    Thanks brake gurus for any and all help.
    ... stainless steel is a bad idea too. I mean, SS is prone to galling. Just get proper rotor bolts. Should be easy to find.

    Then again, I think Hope uses low profile hex head SS bolts. My Hope rotor bolts are getting a bit worn, and it takes a brand new quality allen wrench and lots of careful coaxing to remove them.

  9. #9
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    Hope advise that you use 5nm of torque on M5 rotor bolts... that's no where near tight enough to strip the head of any bolt imo (No matter what material or head type used)

    When I finally went through the effort to use a torque wrench I had to triple check that I was reading Hope's instructions right. And I'll be watching the rotor bolts closely cause 5nm of torque is hardly anything compared to my previous heavy-handed antics!

    I think your best off sticking to regular brake rotor bolts... fit them properly once and enjoy riding (5nm of torque and use blue loctite to ensure they don't fall out... just in case)

  10. #10
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    Mcmaster part # 92832A434 $6 for 50 plus maybe $4 shipping and you'll have them in a day or two.

    92832A434
    (Same as 92832A200)
    Class 8.8 Button Head Socket Cap Screw Zinc-Coated, M5 Size, 10 mm Length, 0.80 mm Pitch
    In stock at $5.82 per Pack
    This product is sold in Packs of 50


    Personally, I'd use stainless since I've only very rarely had problems with it galling in the 20 years I've been working on jetskis, and that's stainless in aluminum around saltwater. My KHS has regular allen heads and plenty of clearance for them.

  11. #11
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    I wasnt gonna say anything else but...

    It makes me smile that a guy can ask a black and white, straight forward question on here:
    What is the pitch of such and such bolt?

    and ten replies will come back.

    Only one person will answer the question.

    Fellas, Not that you needed to know but: This hardware is for installing my new bolt on cog. Therefore it will be a rear only application and the clearance is never an issue out back. Also, the cog may be swapped, even trailside, therefore it is preferred that a multi tool could unbolt it (not that I don't own a full torx and star set). I personally prefer Socket head hardware in this application and have seen others are using it successfully here on MTBR as well. On every rotor I have installed in my life, I have used the torx supplied by the manufacturer and do not disagree with them on rotor installation whatsoever. I acknowledge that Srams new XX group uses nothing but torx all over the place.
    My cog is now installed fine. I was at my buddies house last night having a beer with three shop employees and none knew the pitch of the bolt so I was sent home with an actual rotor bolt and put it to my thread gauge to match it out. M5 .8 x 10mm is the only information on here that was relevant to my question.

    Thanks to all the know-it-alls who didnt know the answer or the specifics of the situation but felt the need to chime in. This forum is good for information, but more so for laughs

    I still love yall,
    10speed
    no chain no gain.

  12. #12
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    So it wasn't for a brake rotor, but a fixie workaround? No wonder you got answers you didn't need....it was a question for the drivetrain forum! You really ride fixie on trail? Do you wear tight jeans when doing so? J/K, if you ride fixie on trail you da man!
    "...the people get the government they deserve..."
    suum quique

  13. #13
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    Quote Originally Posted by Bikinfoolferlife
    So it wasn't for a brake rotor, but a fixie workaround? No wonder you got answers you didn't need....it was a question for the drivetrain forum!
    Ditto!

    I did not give the bolt type because it had been correctly answered twice before I saw the question and well before the OP declared a "winner" (how did he know it was correct).
    mtbtires.com
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  14. #14
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    Smiles for miles fellas!

    Yeah I have been fooling around on xc trails for about two seasons riding a full rigid fixed 26er.

    I like it best but think it is not for 95% of people. Mainly do it for the challenge and to make old trails new again.

    I didn't feel the need to state the purpose of the bolts as it does not effect the answer to the thread pitch. Also, I didn't want this thread to be over run with questions about fixed mountain biking, seeing how this is not the place for such a topic.

    For those who have any interest, check the SS forums when I post my complete build.

    Again thank you to those who supplied the correct information to the actual question.
    The rest of you.... well... see ya on the trail!
    no chain no gain.

  15. #15
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    Quote Originally Posted by 10speedbiopacefreewheel
    ...I didn't feel the need to state the purpose of the bolts as it does not effect the answer to the thread pitch. Also, I didn't want this thread to be over run with questions about fixed mountain biking, seeing how this is not the place for such a topic...
    But you DID ask for replacement rotor bolts and added unnecessary details and comments ("...I prefer socket head stainless if possible, because torx is dumbness...") that invited discussion rather than just-the-facts thread spec. You likely would have received fewer replies had you mentioned fixies.
    mtbtires.com
    The trouble with common sense is it is no longer common

  16. #16
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    Quote Originally Posted by 10speedbiopacefreewheel
    Question:
    I have a disc hub with no bolts. What do I ask for at the hardware store to get replacement bolts???

    I prefer socket head stainless if possible, because torx is dumbness. But I just need to know pitch basically. I am guessing they are M5.
    ....
    Thanks brake gurus for any and all help.

    Notice this, the actual question.



    Furthermore, I felt that had the information about the socket head not been included more responses might have looked like this one:

    Quote Originally Posted by NeverFree
    Why wouldn't the bike shops you called just sell them to you? They must stock them..
    Which is a reasonable reply. You need bolts? then go to the LBS- cause they sell em.
    I expected more of that honestly, and that would've been my response too.



    But really who cares? let's let this thread die. I figured it out the pitch- You figured out that I'm nuts- (about bolts?) and the rest is nonsense. Verdad?
    no chain no gain.

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