Front End Bar Wobble

[Db52280]

Hey guys my 05 Fz6 has developed a pretty bad left to right bar wobble. This is if I let go of the bars at any speed. While holding on you can't feel it. Any ideas on what may cause this? I'm thinking the front wheel is out of balance.

 

[TownsendsFJR1300]

Mileage on the bike?

Is the air pressure corect in the tires?

How worn out is the front tire, any cupping?

Check the front end (forks) for ANY PLAY. Put it on the center stand, jack up the front under the header, then pull/push at the lower end of the forks for ANY PLAY. There shouldn't be any..

 

[FinalImpact]

Hey guys my 05 Fz6 has developed a pretty bad left to right bar wobble. This is if I let go of the bars at any speed. While holding on you can't feel it. Any ideas on what may cause this? I'm thinking the front wheel is out of balance.

First thing I'd do is get the nose in the air (block under the headers), and spin the front tire looking for runout side to side and radially from the tire itself.

Balance issues take off at 40'ish mph while bent parts can be noticed much earlier speed wise and seldom make a left right shake.

Look for bent parts; either the wheel, a bulge on one side of the tire, and maybe but very unlikely a bent rotor. << very unlikely on that last one.

 

[motojoe122]

+1 on the above. I ran into the same problem a while back, turned out to be a defect in my front tire. It caused a nasty head shake.

 

[TownsendsFJR1300]

Just as a side note, on my old (2004) Goldwing, over time, it developed a de-cel wobble 34-45 MPH which was apparently NORMAL for the bike (low miles too).

Not quite the same as yours however the fix was to dump the regular steering head roller berarings and go with the tappered "All Balls" bearings that did fix it.

My money is in the front tire. Any slight cupping will do what yours is.


My FJR, when the ft Bridgestone was at its life end, did the EXACT same as yours (cupping was really bad-just came back from a road trip), terrible bar wobble.

Actually, if you rolled the bike backwards out of the garage, at an angle tlted, you could FEEL the tire cupping, felt like a friggin knobbie on the front. It cupped really bad, really quick closer to the end of its life..

A new tire, all gone....

Good luck..

 

[Puttin Along]

What about the bearings under the handle bars? My friends rode my bike and said about the same thing and checked them, greased as they were good and tightened the nuts and it was all better!

 

[Db52280]

Thanks guys I will check those things. The bike has 40k on it, the tires about 5k. I don't think it's the tire since before every ride I inspect them. I will double check tire and move onto head bearings.

 

[TownsendsFJR1300]

What about the bearings under the handle bars? My friends rode my bike and said about the same thing and checked them, greased as they were good and tightened the nuts and it was all better!

Those are the steeing head bearings. And yepper, if their loose will cause issues.

 

[04fizzer]

Steering head bearings was my first thought. Definitely check those out.

 

[The_Paragon]

FWIW... My '86 FZ 600 did that religiously on decel. Do as much as touch the handlebar with your hand and it quits. Worked through the entire front end, still did it, new tires, old tires, front wheel of my buddie's radian. String aligned the rear wheel. Nothing made a difference.

Doesnt matter now, it sits in a Yamaha collector's Garage, will probably never be driven again.

 

[TownsendsFJR1300]

FWIW... My '86 FZ 600 did that religiously on decel. Do as much as touch the handlebar with your hand and it quits. Worked through the entire front end, still did it, new tires, old tires, front wheel of my buddie's radian. String aligned the rear wheel. Nothing made a difference.

Doesnt matter now, it sits in a Yamaha collector's Garage, will probably never be driven again.

Apparently, with yours and I know the Goldwing, with the tappered head bearings, there's much more surface area to spread the load, which in my case, definitly fixed it..

 

[Db52280]

Thoroughly inspected the tire and it is fine, tire pressure is good. I'm going to put the front end in the air tomorrow and check for looseness. I guess this really only shows up on decel I don't remember feeling it during positive acceleration. Thanks for all the input guys.

 

[motojoe122]

Just to completely rule out the front tire, try this. When you have it off the bike, put the axle through the hub and set it on 2 Jack stands. This way you can give it a spin without the drag from the brake pads. Lightly touch the top of the tire to feel for any abnormal tread wear or deformities while it is spinning. Like I said with my tire, I had not noticed it until the mech pointed it out to me.

 

[FinalImpact]

While the front tire // wheel is off, pull out the wheel spacers # 8 and firmly seat a finger or thumb on the wheel bearing inner race # 3. Push with all your might destroying your thumb/finger while turning. With pressure applied, the inner race of the wheel bearing should feel completely smooth without roughness. Repeat on the other side!

From: http://www.600riders.com/forum/fz6-technical/50116-2007-fz6-parts-reference-diagram-images-x46.html