Swerving

Discussion in 'The Garage' started by indr, Jun 25, 2013.

  1. indr

    indr .

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    #1
  2. hpsVFR

    hpsVFR Hoosier Daddy

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    Your problem sounds like bearings that are too tight. There may or may not be damage (either existing, or due to installing them too tight), but there's going to be no way to tell without removal and inspection.

    Depending on what you've done, your expertise, and how easy it is for you to get to an industrial bearing supplier, it might be worth simply purchasing all new bearings/races, and doing the work over. At the very least, take everything apart, inspect it, verify proper assembly, installation, and torque, and see where you stand.

    Report back with what you find; take pictures often, and annotate them well.:deal
    #2
  3. Motomedic

    Motomedic Long timer

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    Sounds more like steering head bearings that are worn out.

    When steering head bearings wear, they get small dents in the races due to the fact that they don't really rotate, just move back and forth a very small amount during normal riding.

    Since single-track vehicles are essentially balancing over the contact patch, we are constantly making small corrections to maintain an upright condition. When the small dents develop in the bearings, we have to use more force to move the bearing out of the dent, causing us to make a larger correction than we need to. Of course, the next thing that happens is we have to correct back in the other direction to maintain balance, setting up a weave.

    Excessive wheelies will accelerate this phenomemon. :D
    #3
  4. hpsVFR

    hpsVFR Hoosier Daddy

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    I had taken the second post to indicate that the SH bearings had just been replaced, though it's not clear whether or not all races were new.

    Either way, suspect the bearings, and if all the parts weren't new, get all-new bearings and replace them again.

    To expand on something I wrote before, you can often get quality bearings for much less money than OEM/dealer prices, by going to an industrial bearing supplier. It's best to have the old bearings in hand when you go, so the guy at the counter can verify that you're getting the proper replacement.
    #4
  5. Retro

    Retro Just the Facts Ma'am Super Moderator

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    I don't mean to sound like a dick, but I'm sort of a safety first kind of guy.

    A qualified mechanic might be a good place to start. Self-wrenching is fantastic, but your posts make me think you might be a bit of a novice.
    #5
  6. hpsVFR

    hpsVFR Hoosier Daddy

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    Now that we know that your tire pressure is probably dangerously low, and know that you haven't touched your SH bearings, that changes the diagnosis.

    How about we start this over?:deal

    Hi indr! Thanks for posting!

    I understand you have a problem with your bike swerving and being difficult to control. We can help you with this!

    First, we need some additional information:

    -What make/model bike is this?
    -What recent work have you done on it? Provide detail.
    -Do you have a service manual and all the required tools (particularly a torque wrench and any specialty tools required for bearings)?

    Seriously, go ahead and give us a couple of paragraphs explaining what bike you own, and what you've done to it so far. Internet advice is no substitute for an experienced friend/inmate (and by all means check out the regional forum to see if anyone's able to swing by and help out), but we can definitely help make sense of things before you start trying random stuff or spending lots of money.
    #6
  7. hpsVFR

    hpsVFR Hoosier Daddy

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    I agree. Also, as soon as you get into a better financial position, replace all the bearings and races in your steering head. Replacing the ball bearings without replacing the races doesn't help much, because if there's enough wear to have deformed the balls, there's been enough wear to dent or otherwise deform the races (to match the deformed balls).

    There is no need to replace a wheel bearing simply because you've removed it and re-installed it, so long as you did not touch the bearing surface of the race during removal. IF you did strike the bearing surface, replacement of all races and ball bearings is required (again, because the damaged race will deform the bearings, which will damage the other race).

    The other lesson here is that one should always check the basics first, and proceed systematically through a troubleshooting process when dealing with maintenance issues.
    #7
  8. Navin

    Navin Long timer

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    The Ninja 250/300 steering head bearings are garbage. You should replace them with a tapered roller bearing kit from All Balls. I'd be surprised if they give any stability or proper function for more than 1000 miles, if that many.

    If you have steering wobble with no hands on the bars at 50 MPH on decal, they are shot. My brand new 2013 300 needed them at 1000 miles.
    #8
  9. hpsVFR

    hpsVFR Hoosier Daddy

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    It's inside there, yes. The plastic bit is a dust seal on those cartridge bearings.

    Driving with a socket is SOP. Using a Screwdriver to remove is also SOP, but generally, people aren't worried about whether or not they damage the bearing during removal.

    Safety first, then finances, then replace bearings as required. :1drink

    I won't touch the debate between the 'tapered roller' and 'ball' bearing people, except to say that one should be quite knowledgeable about one's bike, and the properties of the various parts (and tools) in question, before engaging in any sort of maintenance, upgrade, or modification.
    #9
  10. Navin

    Navin Long timer

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    It isn't a debate about the type. There are bikes that have perfectly fine ball bearing steering heads, (Aprillia Touno) for example. The Ninja 250 and 300 are not one of them. The bearings are Huffy bicycle quality on these bikes.
    #10
  11. kubiak

    kubiak Long timer

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    sounds exactly what my xr did when i put new bearings in. i over tightened them just a bit and i thought my bike was messed up! i loosened the steering head nut just a tad and it was perfect. you shouldnt have any resistance when turning the bars left or right.
    #11
  12. hpsVFR

    hpsVFR Hoosier Daddy

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    You didn't recommend replacing crappy ball bearings with quality ball bearings, you recommended replacing crappy ball bearings with quality tapered rollers. Presumably you did so for a reason. OTOH, the liability-averse engineers who designed the motorcycle in the first place chose ball bearings, and presumably also did so for reasons (yes, cost was surely one of them). There is at least an implied debate there.

    The point that I am making is that engineering decisions are choices that trade off various operational and economic characteristics.

    IMO, one should have a good understanding of the engineering trade-offs involved before going ahead with design choices. AFAICT, the OP has more pressing issues right now than whether or not to replace the SH bearings with tapered rollers, so I thought that I'd try to side-step the issue.

    If the OP's interested in the subject, there's lots to learn, and it's definitely worth knowing more about how a steering head works.
    #12
  13. joexr

    joexr Banned

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    Sounds like pitted steering head bearings . ALWAYS replace bearings and races together. You've also damaged your wheel bearings. NEVER reuse a bearing you've pounded or pulled out by the inner race. You had probably already damaged them tightening the axle without the bearing spacer. Don't be cheap , do it right.
    #13
  14. Navin

    Navin Long timer

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    As far as I know, there is no complete kit to replace the loose ball bearing components with higher quality, loose bearings and races. Perhaps he could source them at a supply house, but the All //balls kit is complete, cheap and solves the issues these bikes have with poorly fixed steering stems from non caged balls.

    He has more issues than the head bearings, but they are a known flaw on these bikes with a known solution.

    :freaky
    #14
  15. hpsVFR

    hpsVFR Hoosier Daddy

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    That is indeed the kit that we're discussing.

    Whatever sort of SH bearing you end up with, and wherever you get it from, it's crucial to replace all parts of both bearings. In the parts diagram you posted, the upper SH bearings is parts:
    11012
    92047
    92140
    92048

    The lower bearing is parts:
    92048A
    92140
    another bearing race pressed onto your steering stem, not labeled on that sheet

    Getting the bearing race off the stem is the most difficult portion, because of the need to avoid marring the surface on which the race sits. You cannot just pry the race off.
    #15
  16. Navin

    Navin Long timer

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    On my 300 that stem race fell off with a single light tap of a hammer on a regular screwdriver. The fit of these super cheapo parts is quite suspect. No wonder they wobble all over the road! :lol3

    Whatever you do, avoid OEM Kawi replacements, and yes, that is the kit I used. It is very good quality parts, no complaints at all. The whole bike became more stable and "tighter" that it was off the floor.
    #16
  17. hpsVFR

    hpsVFR Hoosier Daddy

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    Since you did not replace the bearing races when you replaced the ball bearings in your steering heads, you may very well have left behind dimpled races, which might be causing this effect.

    It could easily be something else, though, and you've got enough stuff going on with this bike to make any sort of internet diagnosis difficult.

    I can confidently recommend replacing your steering-head bearings (balls and races, both), since you didn't replace the worn races the first time around. Find sources (local bearing supplier, all-balls, etc.), and see what some comparison shopping can do for you.

    I can also confidently recommend finding local, in-person expertise to assist you. There are real limits to what one can do over the internet, and based on this thread, I've reached the end of my expertise.
    #17
  18. Navin

    Navin Long timer

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    They should be good for many tens of thousands of miles!
    #18