[Poo-tee-weet]

Well here's my question, and anyone with the knowledge to answer it....it would be appreciated.

When im going around at about 70mph, i drop a couple gear, get ready to pass like normal, and when i get on it the front starts getting real light (of course) and then starts wobbling like mad, so i have to back off and then it come back down. Anyone know what would cause this? It's done this a couple times. Bike is a 97 900r

 

[Twinsen]

Hmm...

1) Why do you have to drop down not one but a minimum of a couple (2) gears to pass a vehicle?
2) By getting on it, do you mean just barely adding throttle, not exceeding, say 6,000RPM? Or get on it, like full throttle?
3) The only way I could really tell the front getting light is if the wheel was coming up...so, uhh...yeah...
4) As for the wobble, that could be any number of things. You should check every bolt on your front wheel / axle / fork. Maybe check if your front rim is bent anywhere.
5) You're 17 on a 900r? You kin to Rossi or something?

 

[boostnsrt]

most people had the same problem on 900rr's really twitchy front end. several fixes, #1 go to a 17 in front wheel off a cbr 600, #2 ontario triple clamp, #3 steering dampner. i know a hundred people who have done some big tank slapping head shakes on 900rr's....... what the hell are you doing with a 900rr at 17 :dunno

 

[Mantis]

5) You're 17 on a 900r? You kin to Rossi or something?

you're 19 on a Gixxer 1k? Basically the same thing man
:spank

 

[debussy]

you're 19 on a Gixxer 1k? Basically the same thing man
:spank

Haha thanks for pointing that out... gave me a good laugh.

 

[dennisred69]

Every thing they said and check the front tire and see if its cupped I had that problem and it was the tire.

 

[Smitty]

Reason I turned down a CBR900 was the darn 16" front wheel. So natch latched onto a 929 once it was about to come on the market.

Yes the front end of the 900 is a bit twitchy. Also cannot understand the going down 2 cogs to get by a cage at 70mph for that is 110kph & in fact even if in top cog the bike should be able to easily pull by the cage as said speed. IF(?) I felt I really had to get by the cage at much faster pace then 6th I would only go down one cog unless I wanted to simply smoke by him.

As dennis pointed out to take a look at the front tyre for it may be showing signs of wear called "cupping" or "lipping" yet that should also be noticable when at a slower speed if you take your hands off the bars at around 45 to 60mph the front end wants to wobble a bit.

 

[Lawnmower Man]

Might also be an idea to check that the steering stem bearings are not worn & are adjusted correctly.

 

[Poo-tee-weet]

the 900r is actually my dads, i have a ninja 500. He's computer illiterate and i figured the story wouldf juist be alot easier to tell if i said it was mine.

The tires are brand new on the bike also, they have about 500k on them, so they shouldent be cupped. And its also a Ninja 900, not CBR.

 

[Revlis]

Well whoever is riding the bike should also try holding on with their thighs and legs more, keeping the weight off their arms. Oh and RELAXING... It kinda sounds like the double downshift and cranking the throttle open is too scary for whomever is riding it and they are tensing up, holding them bars rigid, and could be causing the problem themselves... Beyond this The older 900's were pretty sharp handlers and were a tad twitchy anyway, make certain it's fitted with a healthy stearing damper, the tires are healthy, and nothing is bent...

 

[Doraf]

Maybe the weight fell off the tire after it was mounted. Tire may not have been sieted right. forks could be bent. Was it doing this before the new tires? If not I would take the thing back to the shop and have a talk with the mechanic.

 

[taziscool]

#1.....no need to drop ANY gears on a Zx9r to pass ANYONE at 70mph.....whether it's you or your dad(sounds like your covering w/ that explanation).

#2 the front end is coming up when you hammer the throttle....and you get scared gripping the bars too tight......this combo can and will cause you to crash if you keep doing it......especially if it comes up while changing lanes(tire is turned and sets down crooked).

#3 check all the stuff everyone else said in the front end...MAKE SURE IT"S TORQUED PROPERLY/not worn out.

#4.....no need to drop ANY gears on a Zx9r to pass ANYONE at 70mph!

 

[Poo-tee-weet]

well hes been riding for over 30 years and this isnt his first litre bike. It was while crossing over a dotted yellow line to pass 4 cars, and he had to get out and in fast enough for 2 more bikes to get by those cars after him....so he dropped gears. Lets just assume the problem is mechanical, i guess the tires not being mounted properly is possible, he also thinks that his forks might be low on oil, and he adjusted the suspension slightly aswell (manuel says its factory set for 160 pounds, he weighs 200 pounds).

Theres a picture of my bike and his......just because your calling me a bullshitter...

 

[Poo-tee-weet]

and the old honda in the backround is the bike i started on (about 3500km)....if anyone cares lol

 

[XNachoX]

You guys are a joke, every single time a person comes on here with a question you flame him for things you have NO IDEA about. Stop being such a damn Gestappo.

 

[wescoas1]

If it was while crossing over a dotted yellow, did he bump the dots with the wheel or something, upsetting the bike? Check your wheel alignment as well, while you're at it. www.sportrider.com I believe still has a good how-to on the subject.

 

[boostnsrt]

if the front wheel is just skimming the road and then grazes by a reflector it will send you into a head shake

 

[slingblade]

you're 19 on a Gixxer 1k? Basically the same thing man
:spank

Not to add insult to injury... He's not on a gix1k now.

 

[vuu16v]

you're 19 on a Gixxer 1k? Basically the same thing man
:spank

No joke. Wearing partial gear and calling everyone else a squid is getting old as well. Pot, meet the kettle. You're both black.