Low speed bouncing

Discussion in 'Rider Skills Help' started by superfly, Dec 20, 2007.

  1. superfly

    superfly Registered User

    Hi all,

    I'm new to the BB world but not to biking and have a bit of a problem with her!
    At low speeds (upto about 40mph) when keeping a constant throttle and in any gear the bike seems to bounce as if there is a bulge in the tyre. Both tyres are fine as are the rims and it has just had a new chain and sprockets fitted. Can anyone help with a cure please?

    Boing, Boing, Boing!!

    Merry Christmas to all of you Blackbird lovers.
    :bang:
     
  2. Raymundo

    Raymundo Registered User Read Only

    Are you hitting the 5500rpm 'flat spot'? Mine does that in the rev range, feels a bit giddy-up.

    Ray
     
  3. superfly

    superfly Registered User

    No, it seems to happen at lower revs than that....generally between 2000 - 4000rpm.
     
  4. mick the knife

    mick the knife Registered User Read Only

    Is it injection or carbed? If it's injected and has cats at below 3000 revs the fuelling is very lean to get it through the EU's red tape, and makes the running not as smooth as other rev ranges. If it's carbed,I aint got a clue on antiques.

    Welcome to the forum
     
  5. mick the knife

    mick the knife Registered User Read Only

     
  6. Duck n Dive

    Duck n Dive Rebel without a clue ... Club Sponsor

    Thinks ..... when I was new to the 'bird I sometimes had a similar problem.


    It wasn't the bike ... it was me!!

    With the digital dash I used to find it harder at first to maintain a constant speed as I was so used to judging the "level off" point from seeing a needle swinging around.

    So to try and find/maintain a constant speed on slow/medium speed roads I was simply holding onto the throttle too tightly.


    I needed to relax a little more and not grip the throttle quite so hard and then everything smoothed out.

    It didn't happen when on changing throttle settings as I was naturally letting the grip relax a bit when opening/closing .....



    It felt just like you're describing ... I guess it was every bit of uneveness of the road was being transmitted through to the throttle and made it feel liek the bike was bouncing.

    Now I've settled down to the bike I find it needss no real pressure/grip at all on either the throttle or the bars to maintain control/speed.... it's possible to simply open my hands and be using only palm pressure ...
     
  7. Artemis

    Artemis Sweetie Goddess Club Sponsor

    Ok, I've waited for a few sensible replies to happen first since this is in the help section, but now all bets are off 'cos there's a newbie in town, so............














    Superfly, welcome to the nuthatch, and here's a question for you






































    Want a sweetie, little boy?
     
  8. superfly

    superfly Registered User

    Thanks to all for your assistance and welcoming me to your nursery.

    The bike is a 1999 fuel injected and so , not a birdysaurus.....but remember




    Dinosaurs ruled the earth baby!!



    Will try the throttle grip issue but it feels more like a tyre issue. Will change the boots in February after a trackday at Snetterton and will keep you posted.

    Artemis - thanks for the offer. Sweeties are on you!


    Merry Christmas and all the best for the new year. Ride safe and fast.
     
  9. Artemis

    Artemis Sweetie Goddess Club Sponsor

    No they're not, they're in my new sweetie basket

    [​IMG]
     
  10. Centaur

    Centaur Site Pedant Club Sponsor

    Get in there quick Artie

    There's a couple of mice eating the sweeties! :eek:
     
  11. big harv

    big harv Happy and Gratefull Read Only

    are there two mice or is it one mouse and someone with their zipper broken3ck04 h1d1ng2
     
  12. Centaur

    Centaur Site Pedant Club Sponsor

    On second thoughts Harv....

    Nah. h1d1ng2 I won't go there....I like my head on my shoulders!
     
  13. robone47

    robone47 Registered User Read Only

    bouncy bouncy

    Hi. I have just bought a 2004 Bird. Having only ridden it once, when I rode it back from Wales. After leaving the motorway and heading down a long downhill section with a not so good road surface I also thought the bike was bouncing.
    After thinking about it for a while i came to the conclusion I was holding on to the throttle too tightly... Every bump caused me to move the throttle.
    I will be going out soon to test out my theory.. As Frankie says RELAX.....
    Cheers

    Rob.
     
  14. silverfox.xx

    silverfox.xx quocunque jeceris stabit Read Only

    Hi ya Superfly, I'm in the City if you want a second opinion.. Jaws is also just in Thetford.


    Welcome to the nut house and its good to have another bog dweller on the site.

    My number is 07927 018284.

    Cheers
    Clive
     
  15. dufus

    dufus use your ignore facility Read Only

    and if you ring that number be warned


    it's ?1.50 a minute and all you hear is a red bird revving.....slowly
     
  16. beachnut

    beachnut Registered User Read Only

    Hi SF - due to a similar problem, with diagnostic help from the guys, I replaced chain and sprockets as they were knackered as suspected - All nice and smooth..
    However with such a smooth bike I noticed on the M5 when in the '50' zone that the bike still seemed to oscillate up and down very slowly - traced the problem to my rear shock, the adjuster screw was out about 4 turns - I restored the standard setting according to the manual and that flattened the ride out nicely.
    Now the suspension is a little hard and I feel the road more so I will tweak it a little back the other way.
    Worth checking maybe?.
     
  17. 4_4_2

    4_4_2 Registered User Read Only

    erm, did you notice the date on this thread before posting your answer Beachnut, it was first posted in 2007!!, maybe, just maybe he has found the answer by now.........8rfl@8rfl@
     
  18. silverfox.xx

    silverfox.xx quocunque jeceris stabit Read Only

    If he did we'll never know, 3 posts and he disappeared, 'cause he's not been heard of since. Either that or he's still trying to remember his password.
     

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