• 12-19-2012
    AK47
    Can an out of true rim cause rotor alignment issues?
    I received a replacement rotor (front wheel) from Avid as it appeared to be warped. I put the new rotor on, which is mounted on an aftermarket set of Stan's Crest ZTR rims/hubs w/ the stock Avid Elixir 3's, and it also appeared warped. I tried adjusting it to no end, and couldn't get it in any position that it wouldn't rub on the pads.

    For an experiment, I put the rotor on the stock front wheel and it runs nearly true and the caliper has no rub on the pads.

    What is going on here? Is the wheel out of true somehow (or is it the hub) that would cause this? Thanks for any insight.
  • 12-20-2012
    jersey0826
    Sounds like the hub is warped. The rim being out of true would not directly affect the rotor. However, if the rim is damaged from a wreck, it is possible the hub was also damaged or bent at the same time. Not the end of the world though. As long as there are no cracks, it is alright.

    I would have the wheel spokes tensioned and the rim trued first. Then remount the rotor. Recheck for true. You may have to true the rotor after it is mounted to compensate for the hub. There are tools for this, and some people do it with an adjustable wrench. You should be fine if you can get it relatively true.
  • 12-20-2012
    LyNx
    Nothing to do with the RIM, your HUB flange needs to be faced, it is obviously not square. Check and see if your local shop has the tool, if not it's not cheap sadly, HOPE makes one, but about $150 IIRC.
  • 12-20-2012
    AK47
    Thanks for the info. LBS said no such tool exists. I'm asking Stan's directly...
  • 12-20-2012
    LyNx
    Another thought on this...Did you realign the caliper when you swapped wheels? If you didn't it could just be as simple as your old stock hub being slightly narrower or wider than the Stans and you need to realign the caliper to the new hubs. Hardly any rotors come 100% true, but they definitely shouldn't have a seriously noticeable wobble when new. Try installing the Stans wheels again and centering the caliper or have the shop do it.

    Sorry, was thinking of the one for doing the fork tabs when IS was the standard.
    Quote:

    Originally Posted by AK47 View Post
    Thanks for the info. LBS said no such tool exists. I'm asking Stan's directly...

  • 12-20-2012
    meltingfeather
    true the rotor.
    i'm a tool-head so i use one of these:
    http://www.parktool.com/uploads/thum...27_430x390.jpg

    a well-cleaned crescent wrench will also work.
  • 12-22-2012
    shiggy
    Quote:

    Originally Posted by meltingfeather View Post
    true the rotor.
    i'm a tool-head so i use one of these:
    http://www.parktool.com/uploads/thum...27_430x390.jpg

    a well-cleaned crescent wrench will also work.

    Or a crescent wrench and a clean rag
  • 12-22-2012
    kcvpr
    It could be a bent or broken axle as well.
  • 12-22-2012
    1niceride
    Mark the rotor in relation to the hub or rim. Notice and mark hi or lo point on rotor. Remount rotor 180 deg. If hi or lo mark followed the rotor, its a bent rotor. If mark stayed with the rim, its the hub. Easy peasy.
  • 12-25-2012
    yetimeister514
    Quote:

    1niceride

    Mark the rotor in relation to the hub or rim. Notice and mark hi or lo point on rotor. Remount rotor 180 deg. If hi or lo mark followed the rotor, its a bent rotor. If mark stayed with the rim, its the hub. Easy peasy.
    :thumbsup:

    Is the new rotor thickness exact same width as old one ? I had this problem and was going crazy trying to figure it out - the supposed replacement was about 1 or 2 mm thicker so I pitched it ......... made a good frisbee !
  • 12-25-2012
    shiggy
    Quote:

    Originally Posted by kcvpr View Post
    It could be a bent or broken axle as well.

    A bent axle can not make a wheel wobble because it does not turn in the dropouts. It can cause alignment issues but that remains the same as the wheel spins.
  • 12-25-2012
    shiggy
    Quote:

    Originally Posted by yetimeister514 View Post
    :thumbsup:

    Is the new rotor thickness exact same width as old one ? I had this problem and was going crazy trying to figure it out - the supposed replacement was about 1 or 2 mm thicker so I pitched it ......... made a good frisbee !

    That is a huge variation considering most rotors are 2mm thick.

    The main reason to replace a rotor is it has worn thin. Usually when they have reached 1.6-1.8mm.
  • 12-25-2012
    yetimeister514
    Quote:

    shiggy

    That is a huge variation considering most rotors are 2mm thick.
    The main reason to replace a rotor is it has worn thin. Usually when they have reached 1.6-1.8mm.

    Yes, agreed. I forgot the decimal and is more like 0.1 or 0.2 mm.- basically a gnat's a** ! Thanks Shiggy !
  • 01-02-2013
    AK47
    Perplexed beyond belief...
    I really appreciate all the ideas, but after my last attempt at a fix, I am really at my wits end...

    I invested $350 on a new set of Shimano SLX brakes (IceTech) w/ the IceTech rotors. And sure enough, the brand new, high end rotor wobbles as well on the ZTR front wheel. I was thinking it also might be a bent skewer (9mm), but after reading above that doesn't sound like the culprit (but I'm going to give it a try tomorrow anyway after a good night sleep just to eliminate that possibility).

    Process of elimination would dictate it has to either be the skewer or a warped hub since the rotor runs true on the stock wheelset. I sent a message to Stan's about it but then never responded.

    Added to this frustration, I can't get the front caliper to center without rubbing!! I was really hoping the Shimano's would mount up trouble free after all the positive reviews I read about them before buying. I know hydros have a better feel and look way better than mech brakes, but damn I don't have these issues with simple mech's like BB7's.

    :confused: :madman: :confused:
  • 01-03-2013
    kcvpr
    Quote:

    Originally Posted by AK47 View Post
    I really appreciate all the ideas, but after my last attempt at a fix, I am really at my wits end...

    I invested $350 on a new set of Shimano SLX brakes (IceTech) w/ the IceTech rotors. And sure enough, the brand new, high end rotor wobbles as well on the ZTR front wheel. I was thinking it also might be a bent skewer (9mm), but after reading above that doesn't sound like the culprit (but I'm going to give it a try tomorrow anyway after a good night sleep just to eliminate that possibility).

    Process of elimination would dictate it has to either be the skewer or a warped hub since the rotor runs true on the stock wheelset. I sent a message to Stan's about it but then never responded.

    Added to this frustration, I can't get the front caliper to center without rubbing!! I was really hoping the Shimano's would mount up trouble free after all the positive reviews I read about them before buying. I know hydros have a better feel and look way better than mech brakes, but damn I don't have these issues with simple mech's like BB7's.

    :confused: :madman: :confused:

    Centering disc brake calipers can be a form of art, especially if the brake you are trying to adjust has cps washers(yes i realize that Shimano doesn't have cps). Its not just you, many others had trouble with adjusting disc brakes.

    It may be time to take the hit to your pride and take it to the pro's.

    EDIT:

    It could even be a problem with the brakes them-selfs... On some avid brakes, I have seen them come with too much fluid in them from the factory, or some other sort of problem many times... In short causing the gap between the rotor and the pads to be too small for proper adjustment. H*ll the mounts on your frame or fork could have been machined at an angle causing the caliper to sit at an angle (in which case they would need to be faced with a special tool).
  • 01-03-2013
    LyNx
    If Stans isn't going to give you any help (try calling as well before you give up) then I'd honestly deal with it yourself.....Very carefully spin the wheel with rotor on and note the place where it runs out, then note the corresponding location on the hub to the nearest hole, then with care very lightly remove material using a file.

    Another way you can check if this would help/work would be to first buy some very thin shims and do the same but instead of filing, add the shims to all the other holes where the run out isn't - shims are available in various thicknesses.
    Shimano BRM755 Shim Spacer > Components > Brakes > Brake Parts and Service Kits | Jenson USA Online Bike Shop

    Quote:

    Originally Posted by AK47 View Post
    I really appreciate all the ideas, but after my last attempt at a fix, I am really at my wits end...

    I invested $350 on a new set of Shimano SLX brakes (IceTech) w/ the IceTech rotors. And sure enough, the brand new, high end rotor wobbles as well on the ZTR front wheel. I was thinking it also might be a bent skewer (9mm), but after reading above that doesn't sound like the culprit (but I'm going to give it a try tomorrow anyway after a good night sleep just to eliminate that possibility).

    Process of elimination would dictate it has to either be the skewer or a warped hub since the rotor runs true on the stock wheelset. I sent a message to Stan's about it but then never responded.

    Added to this frustration, I can't get the front caliper to center without rubbing!! I was really hoping the Shimano's would mount up trouble free after all the positive reviews I read about them before buying. I know hydros have a better feel and look way better than mech brakes, but damn I don't have these issues with simple mech's like BB7's.

    :confused: :madman: :confused:

  • 01-03-2013
    rjkowski
    this may be a shot in the dark, but are you using a torque wrench to tighten the rotor bolts? (assuming you are using a 6 bolt design).

    If not, you may be tightening one bolt more than the others, which could be causing your 'warping'. as you switch the rotors between hubs, you may feel like you are chasing a warp that isn't really there.

    I would recommend torquing the bolts, and then trying to true the rotor in a truing stand using a machinist's dial. If that doesn't fix it, then I'm guessing your hub is somehow warped.
  • 01-03-2013
    meltingfeather
    Quote:

    Originally Posted by AK47 View Post
    I really appreciate all the ideas, but after my last attempt at a fix, I am really at my wits end...

    [...]

    :confused: :madman: :confused:

    Why did you decide not to true the rotor and be done with it?
  • 01-03-2013
    AK47
    Uncle!
    Yep, using a torque wrench for sure. I tried a brand new skewer and that wasn't it. It's some issue with the hub flanges or bearings or both. Definitely a bummer as the Crest ZTR wheelset is 2lbs lighter than the stock wheelset. :(

    I give up and am heading to the bike medic tomorrow with both front wheels in hand...
  • 01-03-2013
    meltingfeather
    Quote:

    Originally Posted by AK47 View Post
    Yep, using a torque wrench for sure. I tried a brand new skewer and that wasn't it. It's some issue with the hub flanges or bearings or both. Definitely a bummer as the Crest ZTR wheelset is 2lbs lighter than the stock wheelset. :(

    I give up and am heading to the bike medic tomorrow with both front wheels in hand...

    Hate to sound like a broken record, but why are you ignoring the relatively easy out of truing the rotor? It takes 5 minutes and you'd be done. :out:
  • 01-03-2013
    AK47
    MeltingFeather - you probably just missed it in a previous post, but I tried the stock front wheel and when using it, the rotor runs true...
  • 01-03-2013
    meltingfeather
    Quote:

    Originally Posted by AK47 View Post
    MeltingFeather - you probably just missed it in a previous post, but I tried the stock front wheel and when using it, the rotor runs true...

    I saw that. Just true the rotor on the new wheel. Done. :thumbsup:
  • 01-04-2013
    LyNx
    AK, did you use the same rotor on both the old and new wheel? Didn't see you mention that, just would assume you would have to keep the variables to a minimum. If you did, then def you've got something going on with the hub, but if by chance you just used the rotor that was already on the stock wheel, put the one off the new wheel on there and see if you still get no rub - If there's no issue setting it up then you know the hub is def your culprit, if there's rub, then maybe your new rotor isn't 100% true..
    Quote:

    Originally Posted by AK47 View Post
    MeltingFeather - you probably just missed it in a previous post, but I tried the stock front wheel and when using it, the rotor runs true...

    Quote:

    Originally Posted by meltingfeather View Post
    I saw that. Just true the rotor on the new wheel. Done. :thumbsup:

  • 01-04-2013
    meltingfeather
    Quote:

    Originally Posted by LyNx View Post
    AK, did you use the same rotor on both the old and new wheel? Didn't see you mention that, just would assume you would have to keep the variables to a minimum. If you did, then def you've got something going on with the hub, but if by chance you just used the rotor that was already on the stock wheel, put the one off the new wheel on there and see if you still get no rub - If there's no issue setting it up then you know the hub is def your culprit, if there's rub, then maybe your new rotor isn't 100% true..

    Whether or not the hub is the culprit he can correct the issue, move on, and start riding the bike by simply truing the installed rotor on the new wheel. If I install a new rotor on a hub and it wobbles, I don't spend a ton of time and money trying to figure out what the problem is. I true the rotor in 5 minutes and go ride. :thumbsup:

    Somehow I don't think the message is coming across. :madman:
  • 01-04-2013
    AK47
    Quote:

    Originally Posted by LyNx View Post
    AK, did you use the same rotor on both the old and new wheel? If you did, then def you've got something going on with the hub[/I]

    Yes I did. Using the same brand new, Shimano rotor, I got the following. ZTR wheel = warped rotor. Stock wheel = true rotor.

    In fact, when I was still trying to use the crap Avid brakes, the LBS said the rotor was warped and have Avid warranty it. When I put the new Avid rotor on the ZTR and stock wheels, same results as above. I'm off to the bike medic now to sort this all out.