brian

Hey there I have a question, I ride a 03 919 (its pronounced nine one nine) j/k.

My deal is when I'm on wide open throttle at the top of forth hit close to red line and let off I get a little head shake, just a touch of it to make your butt pucker. Now my bike is modded a little exhaust pcu forks and such but I was having this issue long before I touched the front end. I installed a steering damper but the problem is still there. The damper is a stock unit off a gsxr so maybe its not enough?

Any how I've been on sport bikes for years (had the 919 a little over a year) and I'm thinking it just may be the ergonmics this the bike has that leads to this? It did it way worse when I put a wider set of bars on it, switched to some protaper cr-hi bars and it subsided back to the way it felt stock. The damper didnt seem to help this problem out although it definitly does help it feel better at crusing speed, and under acceleration and I feel like it feels better going into a corner but that part may be in my head.

So anyone else have this problem, and possibly a soulution? Or is it just the nature of the bike? I also get a touch of it under hard acceleration but it clears up pretty quick, I ride the hell out of it.

Thanks
-Brian

Basspiece919

Is your helmet to big?

brian

lol, I'm gonna assume that was a joke. (i hope)

good one.

Pist-N-Broke

Most important, what rubber you using, and what pressure? Next, how old are they, are the tread blocks worn or feathered on any of the edges?

Next, check the head stem bearings for wear or play. If the previous owners have been popping the front wheel up, and down, might be stem bearings.

Also, how is the setup of your suspension? What is the free sag like? Have you got the rear pre-load all the way up, or down? Fork springs starting to sag? Too light of fork oil?

Is the frame straight? Do you have tremours in the arms?

My old RZ250 of 1985 absolutely hated Dunlop Arrowmaxs', and I found that out for certain when I developed a tank slapper that spat me off at 145KPH on the highway. Funny thing was the wobble had a frequency at 75 KMH too, so I should have known at 145 it was going to be trice as bad. Simply got rid of the dunlops, and put some Avon roadrunners on, and she was sweet. As simple fix as that!

brian

I run pilot sports the pressure is right on, I got it from a older guy that said it was to fast for him so I doubt he was wheelin it but you never know. I looked at the bearings when I put the F4i forks on and they looked great. The bike had 4k miles on it when I got it and now has 13k but its been doing it since I've had it. The front tire is about 50 percent worn if not a little more but it's still got plenty of life in it. The bike came with both sets of keys maint records paperwork even the little key number honda gives you when you buy em new so I doubt it's been down but I guess you never know. I've inspected the frame and there's no damage that I can see..... I do have the rear pre load up 2 clicks from stock cause I weigh 240lbs but I guess I could bump it down one back closer to stock and see if that helps but hows that gonna help under deceleration?

hornet919

i have this problem at around 135-140mph but i think its just the wind is kickin my ass

BigMike919

Ha! Same here! Bought the wind screen and it stabled right out... alittle...

Farab

What Pist-N-Broke said, but I'd get it checked out by a suspension expert ASAP. How old are the tyres?

sbeau1960

Never experienced this problem on mine.

Pacojerte

she just telling you "NO"...she don't wanna do what your trying to do to her....

maybe slap her around a bit...

brian

I'm good at slappin her around, but its just a little unerving. It does it under hard acceleration around 100-120 or so. I think I'm just used to a more stable chasis on a sport bike, maybe I'll try some clip ons... Thanks for the replies. Anyone running clip ons? If so can you give me a brief break down of what you did, thanks again.

hornet919

eeeek!!!! no clip ons!!!!!

brian

i know i know, may as well get a F'n sport bike. guess i"ll just deal with it.

I run a pilot sport in the front and a pilot road 2 out back, the sport on the back just got ate up way to quick only have about 1500 on the road 2 soo we'll see how that goes. I've always ran pilot sports on other bikes I think it's a great tire but I'm open to new options since I've never had a sport tour before. Any suggestions I'm gonna replace the front tire in 2-3k more miles. I ride it like a sport bike most of the time my chicken strips stay small.

hornet919

you sound like me, i want a comfortable bike with great power but still like to rail it through the twisties. honestly, my favorite tire is the pilot power. i havent ran them on my 919 yet, but i used to get decent miles out of them on my sv650. even though you may have to pay a little extra and replace them a little more often than a more touring oriented tire, the grip and smooth ride is well worth it. probably one of the best tires out there imo

brian

been ridin pilots for ever and I gotta tell ya this road 2 rocks, I was a little scepital but I love it. we'll see how it holds up

soundman

On my nine one nine, I've discovered that most headshake is traceable back the the big nut on the seat. At the speeds you're talking about it's possible that you are pulling or pushing on the bars when you roll into and out of the throttle just because you're trying to hang on. Even a little bit of input can translate to headshake when you're hauling ass.

brian

^ lol thanks I'll pay attention to holding on less when i'm "hauling ass"

seriously though I'll try and pay a little closer attention to pressure on the bars and see if I can't clear it up a bit that way, also gonna bump the rear spring back down one notch and see if that does anything.

Pist-N-Broke

Methinks that you mix matching tread patterns / tyre carcasses may be the problem to your shimmy. It is generally well known NOT to cross mix tyres.

Most people can't see the difference in one set of black rubber hoops compared to the next, but believe me there is a world of difference. About the only thing bike tyres all have in common is being black!

There the similarity ends. They have different laminations of steel belted windings, fibre belting, cross ply belting, radial belting, then there are the different compounds, then different tread patterns, tread block depth etc.

I'll bet London to a brick that if you get a matching set of tyres, say front and read Road 2's, you will notice a huge difference.

I remember back in the late 80's when 500cc World Champ Wayne Gardner was testing tyres at Le Mans for Michelin, they put an experimental set of wet tyres on for him to test. Well they went great, so he came in to the pits, and had a break while the tyre techs changed to test another set. Well Wayne went back out on the wet track, and at almost 300kmh the bike aquaplaned and down he went at close to 300kmh. He didn't get seriously hurt, made his way back to the pits and asked what the hell happened, and what sort of tyres were they. The tyre tech guys said they were the same set of tyres that they had sent him out on previously, but they had only turned them around! Well Wayne spat the dummy and said thay instead of pumping water out from under the tyre they now sucked it in, and made him aquaplane at 300 and he come off.! Well what do you think Wayne said when the tyre tech guys told him... "Yeah, we thought that might happen." No poo, this is a true story!

brian

well good effort, but it was doing this when I ran a pilot on both ends. It's not real bad but I'd hate for it to turn into a tank slapper. I'm thinkin since it's pretty minor it may be in the rider.... love the nine but it's different in alot of ways from the gsxr's I learned on and rode forever.

brevity

I've never experienced head shake on mine.

hornet919

that means you need to grab more throttle

brian

Exactly, floor it wide open till the top of 5th. You'll fell it.

Pist-N-Broke

Me either. I bought my Hornet new off the floor, with 0 kms on it, and it has never done anything quirky. After the run in I've also rode it flat out for many klicks, and its as stable as anything I've ever ridden.

My last suggestion is do you get the shimmy on the same stretch of road?
I'd go find another road and see if it does it there. I suggest this because once I could feel a bouncing on my bike at certain speed, and what I found was the surface of the road had a very subtle wave patern on it, which reached a harmonic through my suspension.

brian

Well I can top it out all day and its stable as any other bike I've road. The problem comes under hard throttle. 1st2nd and 3rd are fine top of 4th starts getting a lil squirly and if I let out harsh there I get it to. I'm gonna bump that rear spring load a little softer and we'll see how that goes. I'll post it in a little bit when I try it, next few days.

hornet919

maybe part of the problem is when its full throttle at high speeds the front end just gets a little light and therefore may shake cause its not planted firm on the ground?