Welcome to NESR! Most features of this site require registration, including replying to threads, sending private messages, starting new threads, and uploading files. Click here to register.

Results 1 to 10 of 10

K5 tapered front caliper bolts

  1. #1
    Senior Member
    Join Date
    Dec 2009
    Posts
    653

    K5 tapered front caliper bolts

    I'd like to shoot the person that thought putting tapered head bolts on K5 front brake calipers was a great idea. I'm sure each PO of this bike flinched every time they removed them. I'm just that last in line and the socket for the hex tool is toast. Even with a new hex socket tool has no chance of getting these out. The inside corners in the head are already rounded. With the tapered bolt head I can't grab it with anything. Drilling it or slotting it is a no go.

    To add insult to injury I had removed the 1st 3 bolts when the last one finally gave up and rounded off. Had a 5/8" bolt tig welded to the socket head of the stuck bolt to get it out. Didn't think to the others were in bad shape so...reinstalled them. Dumb move. Should have replaced them all. I can feel each of them giving a bit at the modest 20lbs of torque as I started installing them again. What a shit design.

    Thought to use the flange bolts from my GSXR1000. They were about 3/4" too long. Bikebandit and other sites typically list the OEM bolt with the same tapered head. The only sites that I see carrying flange head bolts for of the same length seem to be made from titanium, and are likely from questionable ebay sources over seas.

    While I get this latest bolt welded and removed I'd appreciate any suggestions for suitable replacements.K5 tapered front caliper bolts-05-front-caliper-bolt-jpg

    0 Not allowed! Not allowed!

  2. #2
    Lifer jasnmar's Avatar
    Join Date
    Mar 2012
    Location
    Chichester, NH
    Posts
    4,409

    Re: K5 tapered front caliper bolts


    0 Not allowed! Not allowed!

  3. #3
    Lifer golden chicken's Avatar
    Join Date
    Nov 2011
    Location
    Attleboro, MA
    Posts
    1,787

    Re: K5 tapered front caliper bolts

    A dab of valve lapping compound on the end of the bit before it strips the bolt has saved me some head/heartache in the past.

    0 Not allowed! Not allowed!
    What's the difference between a bolt and a screw?
    First you screw, then you bolt.

  4. #4
    Unsafe At Any Speeds Jim's Avatar
    Join Date
    Aug 2007
    Location
    :lurk:
    Posts
    12,504

    Re: K5 tapered front caliper bolts

    Pro-Bolt USA.
    can even get the stainless pre-drilled ones

    https://www.probolt-usa.com/stainles...c-ssfbmon190r/

    0 Not allowed! Not allowed!
    Last edited by Jim; 04-06-21 at 12:04 PM.
    EX 105
    Sponsors: Motul, Michelin, K&N, Woodcraft

  5. #5
    Lifer
    Join Date
    Aug 2008
    Location
    holland ma.
    Posts
    2,826

    Re: K5 tapered front caliper bolts

    Quote Originally Posted by Jim View Post
    Pro-Bolt USA.
    can even get the stainless pre-drilled ones


    https://www.probolt-usa.com/stainles...c-ssfbmon190r/
    Stainless is terrible for those bolts. You only get a few uses out of them before they begin to get suspect.

    A word of caution on those bolts, dont use allen keys with the rounded head. Only use ones that are flat and sit straight in.

    I use titanium for those bolts now. Its a pretty common type of bolt in ti.

    0 Not allowed! Not allowed!

  6. #6
    Resident Turkey Tricky Mike's Avatar
    Join Date
    Jun 2005
    Location
    The burbs... where dreams go to die
    Posts
    6,072

    Re: K5 tapered front caliper bolts

    Yeah, stainless, despite being pretty is often a poor choice for high-stress bolts. Cruising McMaster shows a regular M8 bolt in 316 stainless has a typical tensile strength of 70,000PSI compared to an alloy steel equivalent at 170,000PSI.

    0 Not allowed! Not allowed!

  7. #7
    Being A Dick PurplePackage's Avatar
    Join Date
    Oct 2020
    Location
    Chelmsford, MA
    Posts
    2,162

    Re: K5 tapered front caliper bolts

    So why can't you buy a 10.9 grade bolt that fits?

    1. Measure bolt length.
    2. Determine threading. They're always metric. Probably M8 1.25 but maybe not, so measure twice.
    3. Buy 2 replacement bolts (Amazon, Home Depot, etc.) that meet above, if you are paranoid use grade 12.9. Flanged bolts are nice but you can just use washers.

    0 Not allowed! Not allowed!

  8. #8
    Unsafe At Any Speeds Jim's Avatar
    Join Date
    Aug 2007
    Location
    :lurk:
    Posts
    12,504

    Re: K5 tapered front caliper bolts

    Quote Originally Posted by Tricky Mike View Post
    Yeah, stainless, despite being pretty is often a poor choice for high-stress bolts. Cruising McMaster shows a regular M8 bolt in 316 stainless has a typical tensile strength of 70,000PSI compared to an alloy steel equivalent at 170,000PSI.
    interesting. i have the stainless caliper, pad, and fork pinch bolts. never an issue. plus the torque spec is fairly low (16.5 ft/lbs) for pinch bolts

    0 Not allowed! Not allowed!
    EX 105
    Sponsors: Motul, Michelin, K&N, Woodcraft

  9. #9
    Super Adventurer SRTie4k's Avatar
    Join Date
    Mar 2009
    Location
    Dublin, NH
    Age
    39
    Posts
    5,677

    Re: K5 tapered front caliper bolts

    They're not guaranteed to round off just because they are stainless. It just becomes more likely vs non-stainless if they are torqued improperly, galled, rusted, etc.

    0 Not allowed! Not allowed!
    2023 KTM 890 Adventure R

  10. #10
    Resident Turkey Tricky Mike's Avatar
    Join Date
    Jun 2005
    Location
    The burbs... where dreams go to die
    Posts
    6,072

    Re: K5 tapered front caliper bolts

    Quote Originally Posted by Jim View Post
    interesting. i have the stainless caliper, pad, and fork pinch bolts. never an issue. plus the torque spec is fairly low (16.5 ft/lbs) for pinch bolts
    My skydiving rig has a reserve parachute I've never used.

    0 Not allowed! Not allowed!

Similar Threads

  1. Replies: 2
    Last Post: 06-14-12, 02:18 PM
  2. WTB: 06-07 GSXR Front Rotor Bolts
    By senecak19 in forum Wanted
    Replies: 2
    Last Post: 09-12-10, 08:03 AM
  3. WTB Front Caliper Suzuki GSXR 600 '01-'03
    By FirstLightning in forum Wanted
    Replies: 6
    Last Post: 07-03-10, 06:33 PM
  4. WTB 94+ EX500 front caliper
    By Pittenger5 in forum For Sale
    Replies: 14
    Last Post: 06-26-08, 11:23 AM
  5. radial mount brake caliper bolts?
    By akira700 in forum General Bike Related
    Replies: 19
    Last Post: 07-20-06, 11:14 AM

Posting Permissions

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