Rotor warped.

Discussion in '5th Generation 1998-2001' started by vikingGoalie, May 14, 2021.

  1. vikingGoalie

    vikingGoalie New Member

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    So i have some faint pulsing from the front brakes. Mechanic says it's a warped rotor, though he didn't put a gauge on it.
    I assume you just replace both, especially if you are not going OEM. I'm looking at ~$500 for the rotors and new brake pads (seems silly to me to not replace the pads whle you are doing this).

    So questions. After market rotors or OEM ?

    Replace both even if only one is warped?

    I do need to verify that the rotor is indeed warped, but I had a piston that was sticking intermittently, very slightly, and i bet it heated up the rotor and did it in. but will want to check to be sure.
     
  2. TOE CUTTER

    TOE CUTTER Mullet Man

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    I have a local frame repair shop that will check and straighten rotors. I bent the wheels on the Multistrada and while he was repairing the wheels I had him check both rotors and straight one for $110. Had a slight pulse while braking and that was a deal to fix the problem.
     
  3. Thundercats

    Thundercats New Member

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  4. raYzerman

    raYzerman Insider

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    I would check a few things...... assuming caliper pistons are clean and not sticking
    Clips at forward end of pads are in good shape so pads have nothing restricting movement
    Caliper slides greased so the calipers can float freely
    Clean pad retaining pins so pads are free to move, option to put film of high temp brake grease, but I leave them dry.
    Rotate/clean rotor rivets so they are not preventing the rotors floating
    You can test rotor runout with dial gauge, but if none, with handlebars held in place, affix a piece of chalk to a suitable wood block and while you turn the front wheel, move the chalk close to the rotor until it touches at the "high spot". While not a dial gauge, it will give you an indication of the amount of runout. Max runout spec is 0.30mm/0.012". If chalk marks the rotor all the way around, of course, that means rotor is not warped.
    Reinstall calipers and go ride..... did your problem go away/improve?
     
  5. Diving Pete

    Diving Pete Member

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    Before spending any money do this:

    Clean pad retaining pins so pads are free to move, option to put film of high temp brake grease, but I leave them dry.
     
  6. vikingGoalie

    vikingGoalie New Member

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    so I did finally check things and my rotor was in fact warped. local shop(s) that i checked no one would straighten a rotor and i was kinda discouraged to do so by a motorcycle shop (they weren't selling me anything). So hopefully ;) i didn't do a bad thing, but I got EBC rotors and EBC HH pads and had them installed. So question to the collective here. Break in wise, anything special to break in rotors? I mean I've seen this for breaking in the pads. https://www.denniskirk.com/blog/2019/03/06/how-to-break-in-motorcycle-brakes/ but didn't know when replacing the rotors if there is some special something I should do?

    only reason I'm hoping the EBC rotors are fine (everyone loves the pads) is that after i got them and reading reviews from happy customers on amazon motorcycle shop said they stopped getting in EBC rotors because they had a few folks have their rotors warp rather quickly. dunno anything on then this tale from the sales guy at the shop.
     
  7. NorcalBoy

    NorcalBoy Member

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    I wouldn't put much credence into what that "shop" guy said.
     
  8. Terry Smith

    Terry Smith Member

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    I have straightened VFR brake rotors and I did not subsequently explode and die. Actually my rotors went from perfectly pulse-free to horribly shuddery overnight, for no obvious reason, so I can only assume they got a bit of a thump from someone or something. My take on that was they bend easily, so they can also be unbent easily. I did some measuring and the steel rotor was fine, but the alloy carrier was not, so I gently pried that back to true using a pry bar, dial indicator and patience. I did another 20,000 or so km after that and never gave them another thought. Unless I genuinely bend the disc, or the thickness was close to minimum I would be doing this again if I need to. I am very careful when transporting loose wheels now to ensure I don't bash the discs.
     
  9. raYzerman

    raYzerman Insider

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    Yep, I've straightened a rotor or two in the day..... perhaps another thing to check is the rotor's rivets. They crud up and won't "float", so stick a suitable tool/screwdriver/whatever to give them all a spin... bit of brake cleaner wouldn't hurt to flush the rivets. Some have wave washers, others not....
    I see no need to break in rotors, but as usual when new rotors and pads, I don't go smoking the brakes either. Won't take very long for the pads to conform to the rotor surface for full contact.
     
  10. vikingGoalie

    vikingGoalie New Member

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    thx for the replies everyone! I do admit I am fully that guy that fixes everything because I don't like to pay someone to do something that I can do myself. That said, at this point in time I'm stupid busy with work and life (mostly work) and the money is pretty decent so was kinda like f'k it and just got the rotors and pads and it's just done.
     
  11. chuntera

    chuntera New Member

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    you can check the disc rivets or what this brit guy calls "bobbins"
     
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