when you are going realy fast on a dirtbike, is it normal for the front tire to almost swerve a little?

Question

and i mean lik 5 or 6 gear on the street

Answer 1

Yes, it's normal, but not very safe. It happens on regular bikes too. The condition is called a tankslapper because violent ones will cause the handlebars to turn back and forth and slap the tank. This usually happens if you're on a bumpy road and going a decent speed. Very subtle tankslappers are expected from time to time. What happens is the front tire loses contact with the pavement and if it doesn't come down in the same direction the bike is going, a tankslapper will start.

Manufacturers started fitting bikes with steering stabalizers to correct this problem and you can have one fit on aftermarket as well that you can adjust for various riding styles/situations.
I used to increase the pressure on my stabalizer when I was hitting the twisties for faster leaning and decrease the pressure for relaxed riding and more manuverability in low speeds. You just reach over and turn the dial. Newer bikes have auto adjusting ones.

If you get a tankslapper going, the best thing to do is relax your grip on the handlebars. I know this sounds contrary to what you should do, but I read about this in Cycle World. They said that when you grip too hard, you tend to over correct the situation and you make it worse. The natural physics of the front wheel is to go straight so by lessening your grip, you let physics take over and lessen the chance of human error. I've tried it myself because I'd get a tankslapper every time on one particular road on my way home. The technique works.

But, I'd imagine that it's much worse on a dirt bike on asphalt because of the knobby tires.
Slow down or get a streetbike.

Answer 2

I agree with guardrailjim and will add another thought to it. Most off roaders don't balance the wheels on a dirt bike, there's really no need. At W.O.T., especially on pavement with knobbies, the tire being out of balance would have an effect on it too I believe.

Maybe the wheel is out of true just a bit as well. Again, something small wouldn't be as noticeable at 'normal' off road speeds, especially in the dirt. On the road running WFO, maybe?

Answer 3

If you have "knobby" tires, then yes. The "knobs" on knobby tires are made to flex for optimum traction in the dirt. That's why the tires are not rated as street legal. And there is not as much rubber on the road compared to street tires. This gives your tires a "hydroplaning" effect. Also low tire pressures will amplify this effect.

Answer 4

its natural for the bike to be a little unstable but if what i think your talking about is your front tire kind of kicking back and fourth thats gets gnarly. but they sell steering stablizers for that which help a tpn if your willing to spend the dow

Answer 5

It should'nt do that. You may hve bent the wheel. I would recommend checking it out.

Answer 6

ya shift gears &pull back

Answer 7

That doesn't sounds good at all, get it checked out.

Answer 8

check your head bolt

Answer 9

No