Front End Wobble

[arcticflipper]

Really stupid question.....

What is the state of the drive chain?

Is it set close to max?

I've noticed a little unstability from the front - in tight corners, S's and sweeping bends due to the wheel base being on it's max extended...

This might not have anything to do with your problem, but maybe it does help to shorten the drive chain.

[gharknes]

Lift your hands off the steering at 40-50-mph and the steering starts into a wobble and if you didn't get those hands back on there it would wobble out of control, i believe my bearings are worn or need tightened, wheel balance may also have a share in this problem, i doubt that a brand of tyre is the cause.

[ekasXX]

I had this same problem with another bike. I put on a new tire and had it balanced. This solved the problem and it rode smooth from there out. I'd replace the front tire with a matched type and get it balanced.

[tomek]

I would just stick with the easy answer you already mentioned. It's good practice to check steering head bearing adjustment and front tire wear and balance, but I think anything else is overkill, and probably not worth the bother. There is an inverse relationship between stability and maneuverability with motorcycles, just as with aircraft. Front line fighters and aerobatic aircraft are inherently unstable, but this allows them to be highly maneuverable. Inherently stable aircraft, like transport category aircraft, maneuver like trucks-very large trucks.

The same is true with motorcycles. The manufacturer must strike a balance between stability and maneuverability using steering head angle, rake and trail measurements according to the expected use of the particular model. I have noticed the oscillation at approximately the same speed on many road bikes, and as long as I can dampen and control the oscillation with light hand pressure on the bars, I don't worry about it. Now if the bike wanted to go into a tankslapper or weave at that speed, I would truly be concerned.

+1.Just get use to it .If that was Ducati or BMW,wait on BMW, those guys are sooooo perfect,-wrong example-,owners would be bragging about the character etc,,,,There is nothing wrong with the bike.To whatever jrdxx said I would throw frame ,swingarm and front fork flex factor.How about that?

So,just get use to it or spend the lifetime trying get rid of that.

Some bikes just do that,worse on some tires/used tires,better on new ones.

BTW if I remember right my old FJ12 did that too.

BTW what is wrong with tankslapper,my ex- 99 r1 was slapper happy bike.You just have to remember to pump your front brakes.( front pads get pushed away from rotors when it happens)

[Flitemdic]

Man, I don't ever even want to see a true tankslapper. I'm watching this thread pretty carefully, and there are some really good thoughts here. I'm getting the idea I need to get a new front, of course, but no-one had any input about how hard it is to replace the head bearings. Any thoughts?

[FloridaSilverBird]

Same thing happens on my bird, but I didn't really stop to think about it to think it was atypical. I can shift it into neutral and it glides smoothly with no wobble at any speed (although I don't think i've ever taken both hands off the bars at highway speeds and above). It only happens on decel at lower speeds. Engine braking in 6th is enough decel for the front end to develop a wobble, but if I pop it in neutral it never seems to.

Of course, my front pretty much has no tread left and I wont be changing it until right after FUXXT. But this has always been the case.

[Helvet]

Man, I don't ever even want to see a true tankslapper. I'm watching this thread pretty carefully, and there are some really good thoughts here. I'm getting the idea I need to get a new front, of course, but no-one had any input about how hard it is to replace the head bearings. Any thoughts?

Replacing the head bearings yourself can be a bitch.....

You need something to keep the front end up when you remove the forks. After that you need tools to get the old bearings out. An old long screwdriver can do that, but you need a very long one.

The tapered headbearings are harder to put on the bike, because to surface being pressed is larger than with the ball bearings. You need to apply more force without damaging the racing surface. Without a special tool with the right diameter this could be difficult.

Even a skilled mechanic will do the job in more than 2-3 hours.

[gharknes]

i changed my tyres from BT010 to BT012SS and my wobble went away......tyre pressure could also have contributed

[Justin]

Simple answer, after 1500 or so miles a Dunlop front will be cupped on the bird. Great tire, sticky as hell up to 1500 miles, then they go right to shit. I will never run a Dunlop again. FWIW I run Metzeler Sportec on the front and a a Z6 on the rear now. Best tires I have used to date.

[shovelstrokeed]

Most of the 30 or so bikes I have owned over the last 20 years have done that. It takes only a light touch on one bar to make it go away. My current thinking is it is related to rake and trail combined with the slight off center cupping that occurs on almost all tires. I would also venture it is slightly related to rear wheel alignment within the chassis. Careful measurement from the swing arm pivot centerline to the centerline of the rear axle might reveal some misalignment. Don't trust those little marks on you chain adjusters.

I use a set of trammel points to adjust mine and don't notice the problem much on my bike ('01 with 16K miles). Then again, I rarely let go of both bars at once and I have my own, trick, throttle drag deivice.

[TOXXIC]

Same problem here. I run Dunlops because they stick like glue when hot, but cup like crazy. May have to explore a different tire as mileage with Dunlop sucks.

[Para045]

I have a strange problem.

When I let off the throttle, release the handle bars, and I decelerate below 45mph I get a wobble in the front end. I can let go of the bars at 100mph and there isn't any wobble. But as soon as I reach the 45mph mark, the front begins to shimmy like crazy.

I can release the handle bars at 45mph and again it is rock solid. No shaking at all. It is only when I decelerate down through the 45mph mark

Anyone ever have this phenomenon before?

I know the easy answer is to just not let go of the bars.

I think it is the Dunlop tires I have on the Bird, but I am not sure. I am switching out the rear to a Michelin Pilot Road this weekend, but my front is still in great shape. I will let everyone know if switching the rear helps out.

Alright guys, post up with any suggestions.

Simple....

Your tire is CUPPED!

It's a given with Dunlops and Avons.

PR's are smooth.

Same problem here. I run Dunlops because they stick like glue when hot, but cup like crazy. May have to explore a different tire as mileage with Dunlop sucks.

I have just got a 98 Blackbird with 32 000 km's on her and mine seems to do the same thing at around 85 kmh ( just a slight shimmy on coast )and I am thinking it may be the front tyre as you say - I have a Dunlop 208 Sportmax front and a Michelin Pilot Road rear, the rear is ok but the front is nearly worn out and I will replace with a Pilot Power as all the guy's on the OZ Blackbird site seem to rave about them! Just one thing - by cupped I assume that is where the sections between the centre of the tyre and the outer edge seem slightly hollow? . When I pumped the tyres up from 32 psi to 38 it made a bit of difference and also helped stop the bike from running so wide around corners. I never really noticed this cupping phenomena on my old bikes 1983 XS250 and 82 CB750 just feathering on the outer edges is it more prevelent with newer bikes?

[Perky]

I know this is reviving an old post, but I have an update.

I finally changed out the front tire today. The damn thing just wouldn't wear out.

I now have 19,500 miles on the bike, and when I posted the front end wobble originally, I only had 13,500 miles on it. When I replaced the rear tire, the wobble became less noticeable, but was still there. Well, today I put on a Shinko 005 front, and the wobble has disappeared entirely. So, the conclusion is Dunlops suck!!!!

The wobble was due to the tire developing waves in the rubber. I don't know if the right term is cupping, but on the outsides of either side of the two center lines, the tire had humps. Basically, the tire wasn't round any more, but was wavy like the wave rotors. Two lines of humps with varying hills and valleys running the circumference of the entire tire. The left side of the tire was more worn than the right, and the humps were less defined on the left side also. Now I know for certain the wobble was caused by the front Dunlop tire.

What I want to know now, is do any of you think that this phenomenon was caused by improper tire pressure, or do you think it is inherent in the design and construction of the tire? I was running 42 psi in the tire. After speaking with a local bike shop owner, I am lowering the pressure to 39 psi. I'm hoping never to develop the wobble again.

-Steve

[Para045]

I know this is reviving an old post, but I have an update.

I finally changed out the front tire today. The damn thing just wouldn't wear out.

I now have 19,500 miles on the bike, and when I posted the front end wobble originally, I only had 13,500 miles on it. When I replaced the rear tire, the wobble became less noticeable, but was still there. Well, today I put on a Shinko 005 front, and the wobble has disappeared entirely. So, the conclusion is Dunlops suck!!!!

The wobble was due to the tire developing waves in the rubber. I don't know if the right term is cupping, but on the outsides of either side of the two center lines, the tire had humps. Basically, the tire wasn't round any more, but was wavy like the wave rotors. Two lines of humps with varying hills and valleys running the circumference of the entire tire. The left side of the tire was more worn than the right, and the humps were less defined on the left side also. Now I know for certain the wobble was caused by the front Dunlop tire.

What I want to know now, is do any of you think that this phenomenon was caused by improper tire pressure, or do you think it is inherent in the design and construction of the tire? I was running 42 psi in the tire. After speaking with a local bike shop owner, I am lowering the pressure to 39 psi. I'm hoping never to develop the wobble again.

-Steve

Yep its the shit D208's - changed to a Pilot Power front a couple of weeks ago and wobble has gone even on rough roads, had the same as you though the Dunlop took forever to wear out - have done 6000km since my last post and finally were low enough to change the front and the handling is now so much better, feels like "Power steering" (pun intended) turns in quicker, feels lighter and smoother on the road. :icon_clap: Can't even seem to induce a wobble now

[nobbyjeff]

I am currently experiencing a similar problem with the front end of my Bird while accelerating to 60 kph after that all good. I replaced wheel bearings, fitted tapered sterring head bearings, changed fork oil, did a wheel alignment and it was still there. This was driving me nuts as I have never had a problem with wobble. Then i rememberd i had punctured the front tyre the day after it was fitted (couple of months ago) and due to circumstances it was tied down in the back of the ute for a day. I had the tyre repaired and thats when the wobble problem started. After I had done the above trouble shooting work I quized the local bike shop as to whether the repair and /or being tied down for a day may have damaged the shape of the tyre turns out there is a slight deformation in the tyre causing my problem, will fit a new one in a week or so and see if that solves the problem.

I have pretty much always run dunlop tyres but have tried others at various times, Bridgestone, Michelin but have always gone back to Dunlop. I found the 220 very good for about 3000 ks then the front would chop out, still had heaps of rubber but felt choppy in corners. The 207 was very sticky handled well but was all but gone in one good hard ride (too soft). I currently run 205s and am very happy with them (above problem exempted), very predictable, completely stable, good in the wet and good mileage, usually about 8,000ks.

Anyway thats my two bobs worth, ride safe.

[SBBXX]

What I want to know now, is do any of you think that this phenomenon was caused by improper tire pressure, or do you think it is inherent in the design and construction of the tire? I was running 42 psi in the tire. After speaking with a local bike shop owner, I am lowering the pressure to 39 psi. I'm hoping never to develop the wobble again.

-Steve

No one is really certain. A few theories. Heavy/powerful bikes seem to have the most problems with cupped tires. Tread pattern is a factor for sure. My theory is that the tire does not heat up evenly, and therefore doesn't wear evenly. I haven't tried the connies, but the Dunlop, and the Bridgestones all cupped. The Pilot road showed no sign of it at all and that's why there's a second one on there.

I am confused as to why your dealer would suggest lowering PSI to prevent cupping. Mind asking him for me?

marty

[beondwacko]

Steve;

That just goes to show ya' that sometimes it just doesn't pay to wear a tire out before you change it. Sometimes you just have to bite the bullet. Now you can stop in one late afternoon when you are cruising up the coast from Mijami meng'.

[Tricky1100XX]

Oh I had the same problem and I thought all of the suggestions that people gave me was correct. YOU WOULDNT BELIEVE WHAT IT WAS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

The freakin bolts that hold the engine to the frame was missing(2 of them)!!!!!!!!!!!!!!!!!!!!!!!!!!

The others was loose!!!!!!!!!!!!!!!!!!!!!!!!!!!

I ordered 2 bolts ,used a crowbar to align the holes,tightened all bolts,front tire shake gone!! Handlebar wobble,GONE!!!

CHECK THOSE BOLTS THAT BOLT THE ENGINE TO THE FRAME!!!!!!!!!!!!!!!!

When I shifted gears,I heard a knocking sound too.It was the engine moving hitting against the frame!!

I WAS SHOCKED!!!!!!!!!!!!!

[kjclark7]

well i guess add me to the list of front end wobble. i get it while coasting under 45 mph, but its not all the time and its at different speeds. i am running a sportec m1 on the front with about 6000 miles (its got tread left too!!!) and a m3 on the rear with about 1000 miles on it. i have a new m3 front ready to put on but i will probably wait some more time/miles before putting it on. i figured that the front is out of balance becuase of wear but i'll have to wait and see. but i might end up changing to the tapered bearings this winter.

[ZOOMZOOM]

I've got the same problem on my '97, I've had the front end balanced, tried dunlop and bridgestone tires, and yes it seems to happen when I am am at a constant speed below 50mph or decelerating with my hands off the bars. I guess the next step would be check the head bearings. I didn't read all the post so excuse me if someone had already asked this, but how hard are they to change?

[CxBXR]

Only time I get wobble is when under hard accell. in 1 or 2 when the front get's light.

[Para045]

I currently get a wobble on deceleration from about 70kmh-50kmh (43-31mph) with the Shinko 005 that I have on It has done it from when the tyre was new but never did it with the previous PP but did it with the bald cupped D208 on when I got the XX