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Kawasaki Announces "Tech Hold" On New ZX-10R

Discussion in 'Bike Reviews, Questions and Suggestions' at netrider.net.au started by Kermie, Dec 12, 2010.

  1. Not sure if this is hoax, quoted from site.

    Speculation "low oil pressure at extreme lean angles"

    http://www.superbikeplanet.com/2010/Dec/101211kaw.htm

     
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  2. Nah, that's bs.

    Whatever the lean angle, the resultant acceleration is (reasonable assumption for this purpose) straight through the bike from tank to tyres. Absolute maximum resultant for bikes is about √3g. I very highly doubt that would be anywhere near enough to cause a problem when the oil is at 3-4 atm, minimum (ie, its not going to happen). A bit of back of envelope math says the same.

    The point about resultant acceleration on bike is from tank to tyres is this: As far as the bike is concerned, the tyres always point straight down, regardless of lean angle. Therefore, the oil is not bothered by lean angle, but only by the acceleration it experiences, which varies with lean angle. The lean of the bike is not going to cause the oil to fall all to one side.
     
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  3. I'm not sure if this is BS as there are a lot of different bike review sites with the same message.
     
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  4. Where are you reading that the recall has to do with bank angle?

    Good to see the Japanese manufacturers recalling their bikes when there is a fault instead of burying their head in the sand like Kawasaki have done with the oil burning in the KLR and Honda have done with the oil burning in the CBR1000RRs.
     
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  5. That's assuming the rider doesn't hang off the bike in corners. Things like a different C of G and other geometry also affect how much different bikes lean at a given corner speed, and where the oil (and plumbing) is placed relative to that varies as well.

    Anyway, whatever the issue, it must be important enough for them to do this.
     
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  6. For them to offer a buy back option no questions asked means someone in Kawasaki has made a very big bo bo. The last buy back I can think of was with Yamaha's R6 and the PR disaster with tacho that lied claiming the redline was 16,000 rpm.
     
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  7. Yeah, I haven't read anything about the lean angle or anything like that. Just that a recall might be in the works.

    I think the CBR oil burning thing was a problem with the installation of the piston rings. A friend in Sydney who is a bike mechanic said they had a team in from Honda Australia supervising the CBR1000RR's first services - which included an oil change and engine removal and replacement of the pistons. 8-[
     
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  8. So, it needed very little...compared to servicing a Chinese bike....
     
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  9. I cant really see it being lean angle. Its not like it's a big open sump.
    I have no idea how they make them rev so high, put out so much grunt and still have some sort of longevity as it is.
    A race motor takes about two hours to get ready just to start it. They run all the fluids through heaters to get the motor slowly up to running temp before they hit the starter. Or it would not last the race beause the tollerances are that fine.
    Really says something about warming up your ride before you get on it. Or being really careful about buying a low K's "cafe racer"
    Typical friggen journo's. If they don'tknow they just make it up.
     
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  10. The Honda problem was said to be some bikes having slightly oval bores.
     
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  11. OP

    Yes it does, but how much effect would that really have? I mean, how many degrees off centre would the bike be? 5? 10? no more than that surely. As I said in my post, a reasonable assumption.

    Low oil at high g's should be a concern for F1 cars where they hit 4-5g in high speed corners, but should not be a problem for bikes.
     
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  12. Interesting! Well, in Sydney they were taking the top end off and replacing the the pistons. There was an oil starvation problem due to the rings being in the wrong order, or a manufacturing problem with them or something. That could have been seperate from the oil problem?
     
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  13. whoops????
     
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  14. yeah that sums it up
     
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  15. Thanks Blackster
     
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  16. Why there being recalled? Loss of oil pressure following "steep angles" :D:D:D

    [​IMG]
     
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  17. The bike would have to be cornering at a lean angle of 90 degrees for the fluid to be held flat in the sump though. I'm guessing this problem is only on one side, and most certainly, due to the pickup being in a place that does not reach the pittance of oil left in the sump when the majority of it is circulating the engine.

    What you have to remember is the fluid level sits perpendicular to the forces acting on it, but this is not just gravity and the force through the contact patch of the tire, but the vector for centripetal acceleration as well. (or centrifugal for you old schoolers)
     
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  18. Hmmmm, so it's US only?

    Makes me wonder if it's not more fuelling related, the states having the detuned version?
     
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