Rear end bounces/shakes on take off.

Discussion in 'Mechanics Garage' started by TheFrenchman, Jun 2, 2018.

  1. TheFrenchman

    TheFrenchman New Member

    Country:
    United States
    Joined:
    May 24, 2018
    Messages:
    21
    Likes Received:
    1
    Trophy Points:
    3
    I have a pretty weird situation with my 97 VFR.
    When cold, she is just perfect.
    After she gets to operating temp, taking off in 1st gear is very choppy. I can feel the rear end bounce on take off. Every other gear, full acceleration, downshifts, etc are all perfect. No clutch slippage at all even at full acceleration to redline.

    Feels like the clutch slips and grabs when taking off in 1st gear. Hard acceleration, slow acceleration, I can feel the bike shake.

    Any ideas?
     
  2. FJ12rydertoo

    FJ12rydertoo Member

    Country:
    United States
    Joined:
    Mar 28, 2008
    Messages:
    2,245
    Likes Received:
    270
    Trophy Points:
    83
    Location:
    Platte City, MO
    Map
    What kind of shape is the chain and sprockets?
     
  3. TheFrenchman

    TheFrenchman New Member

    Country:
    United States
    Joined:
    May 24, 2018
    Messages:
    21
    Likes Received:
    1
    Trophy Points:
    3
    They look fine to me. How could that effect it?
     
  4. FJ12rydertoo

    FJ12rydertoo Member

    Country:
    United States
    Joined:
    Mar 28, 2008
    Messages:
    2,245
    Likes Received:
    270
    Trophy Points:
    83
    Location:
    Platte City, MO
    Map
    If either one or both of the sprockets is shot, you could have the chain jumping over teeth on the
    sprocket. Also could happen if the sprockets are worn, and the chain is adjusted with too much
    slack.

    You're applying maximum torque to the sprocket in first gear, so if it's going to slip or jump over
    sprocket teeth that is when it would happen.
     
    34468 Randy likes this.
  5. TheFrenchman

    TheFrenchman New Member

    Country:
    United States
    Joined:
    May 24, 2018
    Messages:
    21
    Likes Received:
    1
    Trophy Points:
    3
    The rear sprocket and chain is new. I’ll check the front sprocket when I get home and post pictures of everything so we can see.
     
  6. Egg on Leggs

    Egg on Leggs New Member

    Country:
    United Kingdom
    Joined:
    Jun 1, 2008
    Messages:
    50
    Likes Received:
    20
    Trophy Points:
    8
    Location:
    Birmingham, UK.
    Map
    One thing to consider, this may be wear on the clutch basket fingers. Notching by the clutch plates can have this effect.
     
  7. FJ12rydertoo

    FJ12rydertoo Member

    Country:
    United States
    Joined:
    Mar 28, 2008
    Messages:
    2,245
    Likes Received:
    270
    Trophy Points:
    83
    Location:
    Platte City, MO
    Map
    The thing that bothers me is the OP talking about the rear end bouncing when leaving a stop. I
    wonder if there's an issue with the cush drive?
     
  8. TheFrenchman

    TheFrenchman New Member

    Country:
    United States
    Joined:
    May 24, 2018
    Messages:
    21
    Likes Received:
    1
    Trophy Points:
    3
    It has 22k, could been rode hard before I had it. It does have holes in the fairings for frame sliders after all....
     
  9. TheFrenchman

    TheFrenchman New Member

    Country:
    United States
    Joined:
    May 24, 2018
    Messages:
    21
    Likes Received:
    1
    Trophy Points:
    3
    Cush drive? Only Cush I know of has nothing to do with bikes and has to do with plants.
     
  10. FJ12rydertoo

    FJ12rydertoo Member

    Country:
    United States
    Joined:
    Mar 28, 2008
    Messages:
    2,245
    Likes Received:
    270
    Trophy Points:
    83
    Location:
    Platte City, MO
    Map
    I don't know about plants, but the cush drive is in the rear sprocket area and is supposed to
    smooth the transfer of power from the engine to the rear wheel.
     
  11. squirrelman

    squirrelman Member

    Country:
    United States
    Joined:
    Jul 27, 2006
    Messages:
    9,839
    Likes Received:
    743
    Trophy Points:
    128
    Location:
    Buffalo, NY
    Map
    Rear shock bad ?
     
  12. TheFrenchman

    TheFrenchman New Member

    Country:
    United States
    Joined:
    May 24, 2018
    Messages:
    21
    Likes Received:
    1
    Trophy Points:
    3
    Thanks for the tips. I’ll be checking her out tonight and posting pictures!
     
  13. TOE CUTTER

    TOE CUTTER Mullet Man

    Country:
    United States
    Joined:
    Nov 30, 2008
    Messages:
    6,731
    Likes Received:
    85
    Trophy Points:
    78
    Location:
    Sacramento
    Map
    Is it possible the dogs and shift fork is damaged? Just a thought. I know it is rare for first gear to have this issue but I thought I would throw it oot there.
     
  14. TheFrenchman

    TheFrenchman New Member

    Country:
    United States
    Joined:
    May 24, 2018
    Messages:
    21
    Likes Received:
    1
    Trophy Points:
    3
    Here’s pics of the front and rear sprockets.
     

    Attached Files:

  15. TheFrenchman

    TheFrenchman New Member

    Country:
    United States
    Joined:
    May 24, 2018
    Messages:
    21
    Likes Received:
    1
    Trophy Points:
    3
    Just noticed clutch fluid level was below the line when the bike is on the center stand.
     
  16. FJ12rydertoo

    FJ12rydertoo Member

    Country:
    United States
    Joined:
    Mar 28, 2008
    Messages:
    2,245
    Likes Received:
    270
    Trophy Points:
    83
    Location:
    Platte City, MO
    Map
    Those sprockets look good to me.
     
  17. TheFrenchman

    TheFrenchman New Member

    Country:
    United States
    Joined:
    May 24, 2018
    Messages:
    21
    Likes Received:
    1
    Trophy Points:
    3
    Chain and sprockets are new. Is there a way to adjust the clutch lever? It might not be fully releasing, clutch might be slipping. It’s only when it’s warmed up. Would changing the oil help?
     
  18. OOTV

    OOTV Insider

    Joined:
    Aug 20, 2011
    Messages:
    6,479
    Likes Received:
    949
    Trophy Points:
    143
    Location:
    Anaheim, Ca.
    I had a similar issue on my 5 Gen once and realized that I missed the engine oil change interval, I was dealing with my other two rides and had neglected the 5 Gen. As far as your clutch line fluid, I would flush/fill it and bleed the line and double check your drive chain slack.
     
  19. TheFrenchman

    TheFrenchman New Member

    Country:
    United States
    Joined:
    May 24, 2018
    Messages:
    21
    Likes Received:
    1
    Trophy Points:
    3
    I am going to be replacing the oil and filter this week. Clutch fluid and brake fluid will also be taken care of. The drive chain slack is within specs.
     
  20. squirrelman

    squirrelman Member

    Country:
    United States
    Joined:
    Jul 27, 2006
    Messages:
    9,839
    Likes Received:
    743
    Trophy Points:
    128
    Location:
    Buffalo, NY
    Map
    when testing the chain, it's important to get the bike up on the centerstand, spin the rear wheel, press up on the chain, and feel for a series of loose-then-tight spots.

    proper chain adjustment must be set at the tightest spot on the chain run.
     
Related Topics

Share This Page