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The bikes 'nose' staying down until take off...??

Discussion in 'Technical and Troubleshooting Torque' started by Dakotabre, Sep 14, 2009.

  1. Morning All,

    Sorry I couldn't search if this problem has been mentioned before as I as I don't know what the parts are called to use in the search :)

    Ok, so I've noticed that more times than not, when I'm taking off from stopping at traffic lights, my front nose part of the bike lifts up, (not the wheel, just the head part) It lifts up as I'm letting out the clutch and accelerating.. (I am NOT holding the brakes on before take off, I'm just holding in the clutch in 1st gear while waiting for the green light)

    The only thing I can think of which might be causeing this uplift on the front, is that, when I use the brakes and come to a stop, I know the nose dips when you use the front brakes... Those two metal forks (?) go down into those tubes (haha I really need to learn the mechanics terms) and then I thought they would bounce bake up again once the brakes have been taken off? So, it's as if, the long forks are staying down in those tubes and not releasing until I try to take off...

    Does all that make sense? Is that suppose to happen? Or are those forks meant to bounce back up as soon as you release the brakes? Or is there any other reason why the front end could be lifting up? And... Is this a major problem or nothing to worry about?

    Thanks in Advance :)
  2. What bike do you have?

    Yep, those tube things that get longer and shorter are the front suspension, also referred to as forks.

    Acceleration and braking = weight transfer.

    Acceleration = weight to the rear.
    Braking = weight to the front.

    How much your bike squats and dips depends on your suspension, and if it is fully adjustable, it also depends on the compression damping and rebound damping settings. However venturing into that world of suspension my knowledge is extremely limited. Paging someone suspension knowledged to the floor.
  3. Oh Thanks Brownyy, yeah, the bike model might help hey!!

    CBR125R 2007 Model (Just a baby bike)

    Regarding the Acceleration and braking - weight transfer, that makes sense, but I would have thought that the weight would even out once the brakes are released and I'm just sitting there upright at lights??
  4. Ok i'm making an assumption that I'm pretty confident on that your bike doesn't have adjustable suspension. The pre-load on the read maybe but the front will be fixed.

    Your bike is pretty light in the grand scheme of things and will have suspension to suit. The more weight you put on the bike (one rider, two up, one with a heavy bag etc etc) the more weight transfer you will experience. (I once put a mate (130kg's) and me (70kg's) and a six pack (2kg's?) on the back of a ZZR-250 (150kg wet), that was epicly scary, it virtually had no suspension (or handling, or braking)).

    Trying to picture the image, in theory the bike should be sitting level at a stand still. When you take off and accelerate, it should lean back and nose up. Once you stop accelerating and hold a constant speed it should level up again. Once you start braking, the nose should dip until you release the brakes or stop. But in both cases, the bike should be level while your speed remains unchanged, i.e. riding a constant speed or stopped; no acceleration or deceleration (braking). To have it not level out is strange IMHO.

    Again, this is going down the suspension path, and someone suspension knowledged needs to fill in the technical gaps.
  5. Try this, when you come to a stop, release the brakes. Let the bike settle. You'll notice when you take off the front will raise.

    You will notice the front end lifts quite substantially. However, this is normal. It can be unsettling if you come from a non-motorbike background. Bikes move around quite a bit, and eventually you will learn to compensate. When braking hard the front end might dive down as well...quite normal.

    Your car does it too, but people dont notice as much. Hell even F1 and v8 supercars do it. You can see it on tv when they get hard on the brakes the front end dives a bit.ad

    Personally, I dont like it too much on a road bike...you can do modifications to reduce this, but you may lose some ride "comfort". You should try a dirt bike, with their tall/soft suspension it can feel like riding a freaking horse.
  6. #6 Liq, Sep 14, 2009
    Last edited by a moderator: Jul 13, 2015
    Watch the front end of the motorbike in this video.


    You can see how after he stops the suspension really bounces back upright, theres a lot of travel up/down. Thats a more touring orientated bike with a fairly large suspension range, but you get the idea.
  7. #7 Liq, Sep 14, 2009
    Last edited by a moderator: Jul 13, 2015
    Hereis another good one, see how much the bike moves aroudn ? [media=youtube]3d6iu-1WFxw[/media]

    Just reading your original thread, when you come to a stop yes, the bike should level out when you release the brakes. If you think the pitching is excessive, or its much worse than when you first got the bike, it is possible the forks are sticking...take it to a mechanic/dealer or call up a riding friend (if you have any?).
  8. Liq - Thanks I had a look at those videos, and I see what you mean about the dipping and rising of the front end of the bike.

    My bike so far, appears to be doing the dip, but it stays dipped even after I release the brakes and come to a complete stop, and it only releases once I start to accelerate to take off. so it is sticking.

    So I see now, that it's not normal to be doing that, so I'll go get it checked out by a mechanic :)

  9. wouldnt be too worried. they are little bikes and thus will 'squat' a touch. although if it is staying right down even after releasing the brakes it could be an issue. are they bent ?.
    the 125 does not have adjustment front or rear.
  10. Hi OldBellHelmet :)

    I don't think they are bent, not that I can see anyway. I'll watch/feel it closely over the next few days and if it continues I'll get it checked out.
  11. yeah a bit odd. forks tend to get soft and not stick..get someone to have a look and see to be safe
  12. And congratulations on noticing this. While it may not be a big deal, it does sound like something is not quite right, and very observant of a new rider to pick this up. Well done.
  13. Helpful replies.

    Perhaps a NR in the shire could have a quick squiz, they'd figure it out for you pretty quickly. My guess is that it's normal behaviour (and made worse that it probably has very squidjy suspension). Although there is the slight possibility that it's having issues.

    (On a side not, when you take off hard BOTH the front AND the rear suspension actually rise up. Just due to the suspension geometry. Pretty cool, huh!)
  14. like a 1982 gemini