Bike drag. Video of rear wheel included.

Discussion in 'Technical' started by CBR250, Jul 22, 2013.

  1. CBR250

    CBR250 Ol'Timer

    Hey guys,

    I had a problem about a month ago. The bike picked up a lot of drag from somewhere. The dealer said they checked everything it could be, there was also way too much oil in it from the previous service. They changed the oil free of charge to the correct amount and suddenly the bike was perfect again.

    Then unbelievably 3 weeks later it came back from out of nowhere even worse. Feels like there's a massive elastic band attached to rear of the bike and a far off wall in the low and mid end.

    • I checked the brakes but there doesn't seem to be rubbing.
    • Front wheel turns fine.
    • Cleaned and checked the airfilter.
    • Tire pressure is fine.
    • Chain is not too tight or too loose. Is cleaned and lubed.

    Two things that I think may be a problem:

    I recently had the battery and stator changed, and also a GPS cable attached the battery with a plastic spliter added so it just runs to a plastic plug with no GPS attached to it.

    So could be a power issue from some of these?

    Also took a video of the rear wheel spinning. Please take a look and see what you think.

    Perhaps could be a misaligned chain/sproket?
    Or bearings?

    Unfortunately I don't know how the wheel spins when there's not an issue, so can't definitely say that that's where the problem is. Seems like a lot of clattering noise but not much forcing the wheel to stop turning.

    (ps, the clattering noise is slightly louder in the video than in real life)

    Thanks for any opinions.
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  3. Vic Alborn

    Vic Alborn Ol'Timer

    Have you re-checked the oil level? Silly question, I know, but the crankcase may be making "oil level" through an internal fuel leak. Any problems with the Fuel Injection System?
  4. Vic Alborn

    Vic Alborn Ol'Timer

    Another thought: Is the stator tight? It may have loosened off and is rubbing on the rotor. (The shop may have discovered this, tightened it, but said nothing. Now it may be loose again?)
  5. DesmoNut

    DesmoNut Active Member

    First off, apologies for the crap formatting of this post - I'm having problems with the forum today. When you're spinning that rear wheel by hand the transmission's in neutral so it can't be a stator problem or any other internal engine problem. The rear wheel should be almost silent when turning. Sounds to me like rear wheel bearing(s) - quite likely the cage(s) broken, allowing the balls/rollersto move abnormally. This doesn't always show itself during a casual "wheelwobble" test, unless the bearing damage is advanced, but shows-up in increased wheel friction & noise which gets worse as you get faster. Take the wheel out and physically check the wheel bearings so that you can actually see the ball/rollers & cages. Do it yourself if you're able - it's an easy task especially as you already have a stand to lift the back wheel - or make sure you're on-the-spot if it's done at a dealer, so that you can see the actual condition, not just what they want to tell you. After all, “... the dealer said they checked everything it could be” so the wheel should be fine, shouldn’t it ;) ? If not, question the competence of your dealer - never a bad idea here in Thailand, anyway. ? Another thing to think about is that, by using the bike with this drag problem, you might have damaged your clutch to some degree but don’t worry too much about that unless you experience clutch slip on the road - I'm probably scaremongering a bit there. road. Do you use a pressure washer to clean the bike? Using a jetwash is a good way of washing grease out of your wheel bearings. Best to just use a bucket & sponge.
  6. Vic Alborn

    Vic Alborn Ol'Timer

    I agree with DesmoNut, however the noise is hard to decipher on the video and I took it to be normal chain noise. And I was under the impression the wheels turns freely when spun-up by hand. (Of course, if the rear wheel bearings are damaged, the wheel may turn freely when off the ground anyway). As he suggests, water-blasting in the vicinity can wash/dilute the grease in the bearings so that is worthy of checking in the manner he describes. Keep us all posted as we can all learn from your experience. Cheers
  7. Vic Alborn

    Vic Alborn Ol'Timer

    I must be getting old as my thoughts are coming one-at-a-time: If it is not wheel bearings, my Yamaha has a warning placard under the seat about not carrying anything, such as a rain suit, too close to the air-box as it may obstruct the airflow. Also, (and this won't be enough to cause your problem but may cause a chain noise): I took the Yamaha to get cleaned once and the flexible guard forward of the rear wheel became detached by the pressure of the water-blaster and was rubbing on the chain. Not audible when riding but was when the rear wheel was spun by hand. Maybe you have already checked but I am just trying to cover all the bases. Cheers
  8. sam14300

    sam14300 Member

    Just a suggestion, to isolate noise area. Remove chain completely. Rotate rear wheel and observe noise. Run engine with chain REMOVED, through the gears and observe noise. It realy sounded like chain noise to me, but this should take the chain out of the question.

  9. Vic Alborn

    Vic Alborn Ol'Timer

    Have you tried any of the suggested fixes yet or found the problem?
  10. DesmoNut

    DesmoNut Active Member

    Come on, CBR250, some of us took the time to respond to your questions with positive suggestions but you've not had the courtesy to let us know whether or not our info. has been useful to you, not even just a simple "Thanks".
  11. CBR250

    CBR250 Ol'Timer

    Sorry, and thanks guys, I haven't been online. :)

    I did a few small things, such as replacing airfilter, running it without the airbox for a few days and adjusting the clutch, it oddly enough disappeared over time, and I would guess that it was clutch related.

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