Front wheel wobble

From what I have absorbed so far front wheel wobble can be caused by and corrected by addressing the following or a combination of the following:

1. Front wheel out of balance
   
2. front fender brace upgrade
   
3. tightened cinch bolts on front forks
   
4. Furbur washer fix
   
5. solid motor mount upgrade
   

Have I left anything out.

Question: Can it also be caused by unequal amounts of fork oil in each of the forks?

Oil level in forks can contribute to a wobble. With our forks where the left is tied to the right for air it is not as bad. On a regular set of forks it can be very exciting on a good sweeper. I would also add fork tube alignment to your list. Not tightening things from the axle up to the top can put twists or stress on the fork. I am mailing SkyDoc17 my washer in the morning so he will have a pile of Furbur type washers. Remember as you are working through the steering problems, the rear has to be checked. An out of specification or loose swing arm will cause bad tracking and induce problems. I would put that higher on the list than the motor mounts. I think the solid mounts might help mask the swingarm bushings. If the rear vibrates, then the worn motor mounts might be amplifying the problem. Good luck, I am still chasing mine to an extent.

Other thing to add is LOOSE STEERING BEARINGS - #1 CAUSE

JB

I had a front wheel wobble that would occur around 40mph, usually on deceleration. I checked the air in my tires and found them a little low. Aired front and rear up to the level recommended by the tire manufacturer and that cured my wobble.

Dean

From what I have absorbed so far front wheel wobble can be caused by and corrected by addressing the following or a combination of the following:

 

1. Front wheel out of balance
   
2. front fender brace upgrade
   
3. tightened cinch bolts on front forks
   
4. Furbur washer fix
   
5. solid motor mount upgrade
   

Have I left anything out.

 

Question: Can it also be caused by unequal amounts of fork oil in each of the forks?

You asked about the front wheel problem. From what I've seen, there are two fundamentaly different types of wobbles - the high-frequency front wheel oscillation, usually worst in decel around 40 mph, and the lower frequency (~3 per second) whole-bike weave that happens at higher speed. I'm assuming you are referring to the first one.

That said, right there with #1 I'd add front tire wear pattern. I've cured or improved this problem on various bikes with a new front tire but never knew if it was the wear pattern or the balance. A have always wanted to rebalance a tire after the problem started and see if I fixed it, but never got around to it.

Also high on the list is the condition of the steering head bearings. Folks here also say tightening the preload on these bearings helps, although that has not been my experience.

I'm under the impression that #5 is more for the hi-speed weave.

My 2 cents,

Jeremy

I had the decel wobble also. Air pressure affected it, however it went away with a new front tire for me- Elite 2.

Bob

You asked about the front wheel problem. From what I've seen, there are two fundamentaly different types of wobbles - the high-frequency front wheel oscillation, usually worst in decel around 40 mph, and the lower frequency (~3 per second) whole-bike weave that happens at higher speed. I'm assuming you are referring to the first one.

 

That said, right there with #1 I'd add front tire wear pattern. I've cured or improved this problem on various bikes with a new front tire but never knew if it was the wear pattern or the balance. A have always wanted to rebalance a tire after the problem started and see if I fixed it, but never got around to it.

 

Also high on the list is the condition of the steering head bearings. Folks here also say tightening the preload on these bearings helps, although that has not been my experience.

 

I'm under the impression that #5 is more for the hi-speed weave.

 

My 2 cents,

Jeremy

My '85 Royale is doing the low speed "dance" where the handlebars will start into a tank slapper if I let go of them below 50mph. I expect the problem to be the front tire (Elite with lots of tread, been sitting for awhile and could be dry).

My more urgent problem is the fork flex I am experiencing. I am used to the tight and solid handling of my ZX11D7 and the Royale front-end seems to have way too much fork flex (although I did drag the toe of my boot last week while turning into my street). It also wants to pogo in a high speed turn (off ramp). It has a Super Brace installed and I am running 20psi front/55psi out back. Any ideas what will reduce the flex?

I agree with lonestarmedic....the #1 cause of front end wobble is a loose steering head bearing...Tighten that first to see if it fixes your problem before diving into it with both hands...Also, 40 LBS of air in front tire..Now I know some will disagree with the air amount but figure somewhere between 38-42 LBS..

It has a Super Brace installed and I am running 20psi front/55psi out back. Any ideas what will reduce the flex?

I do believe that 20psi in the front forks is a bit too much.

RandyA

My '85 Royale is doing the low speed "dance" where the handlebars will start into a tank slapper if I let go of them below 50mph. I expect the problem to be the front tire (Elite with lots of tread, been sitting for awhile and could be dry).

 

My more urgent problem is the fork flex I am experiencing. I am used to the tight and solid handling of my ZX11D7 and the Royale front-end seems to have way too much fork flex (although I did drag the toe of my boot last week while turning into my street). It also wants to pogo in a high speed turn

New tire took most of my front wobble away, but not all. If I tap the bars with my hand or hit a rock in the road which similarly excites the front end, the wobble still starts. This does not happen on my Virago, but it has more rake. This is OK, I ride with my hands on the bars anyway. The bad part is that I've had 2 emergency (as in I thought I was dead) stops in the last year and under heavy braking the front wheel wobbled severely. By the grace of God I stayed upright in both cases.

How do you detect fork flex? I'm not sure what that feels like - can you describe it? I think the only things you can do about it are the Superbrace and make sure everything in the front end is tight. I think an 800 lb bike tends to have a bit of it unless the fork tubes are huge. As for pogo-ing: if you have stock front springs they are probably weak. Progressives or other replacements lifts the front a little and pretty much makes air pressure in the forks unnecessary. Also change your fork oil, making sure you put in the right quantity.

Jeremy

Jeremy

How do you detect fork flex? I'm not sure what that feels like - can you describe it? I think the only things you can do about it are the Superbrace and make sure everything in the front end is tight. I think an 800 lb bike tends to have a bit of it unless the fork tubes are huge. As for pogo-ing: if you have stock front springs they are probably weak. Progressives or other replacements lifts the front a little and pretty much makes air pressure in the forks unnecessary. Also change your fork oil, making sure you put in the right quantity.

The flex is noticed when I am cornering at any speed above 25mph. In the corner I can turn the bars and feel the front wheel wanting to wander. My ZX11D7 weighs over 600lbs (Venture Royale is 716lbs) and stays solid through corners. You are the second person to suggest that my front springs could be weak and causing some of the these symptoms. At over 61,000 miles maybe I need to replace the springs . . .

The flex is noticed when I am cornering at any speed above 25mph. In the corner I can turn the bars and feel the front wheel wanting to wander. My ZX11D7 weighs over 600lbs (Venture Royale is 716lbs) and stays solid through corners. You are the second person to suggest that my front springs could be weak and causing some of the these symptoms. At over 61,000 miles maybe I need to replace the springs . . .

I don't think new springs will help flex, but they should firm up the ride, help with pogo-ing, and prevent bottoming. You didn't mention bottoming, but it is common. Running max pressure in the forks kind of approximates better springs, but IMHO it's hard on the fork seals. I did preload measurements on my Venture a while back and with max air the front end was not too bad before the spring change, but it's better since.

What's the fork tube diameter and length on your ZX compared to the Venture? If they're fatter or shorter or the inverted design they will be stiffer. One guy here reported the Superbrace taking away alot of his fork flex. As for me, installing the Superbrace didn't do anything that I noticed. But you already have that.

Jeremy

I don't think new springs will help flex, but they should firm up the ride, help with pogo-ing, and prevent bottoming. You didn't mention bottoming, but it is common. Running max pressure in the forks kind of approximates better springs, but IMHO it's hard on the fork seals. I did preload measurements on my Venture a while back and with max air the front end was not too bad before the spring change, but it's better since.

 

What's the fork tube diameter and length on your ZX compared to the Venture? If they're fatter or shorter or the inverted design they will be stiffer. One guy here reported the Superbrace taking away alot of his fork flex. As for me, installing the Superbrace didn't do anything that I noticed. But you already have that.

 

Jeremy

Bottoming of the forks only occurs when the air is under 10psi.

I just checked the specs: ZX11D forks = 43mm x 4.7" travel

Venture forks = 40mm x 5.5" travel

You were right, the ZX11D forks are shorter, fatter, and carrying less weight.

Maybe I need to replace the forks on my '85 Venture Royale!

Any recommendations from the group?

I wonder if it isn't the ability of the fork tubes to react equally??? Hit even a very small bump, and the front tire starts to wobble. Hit the brakes and the front tire starts to wobble. With the hands on the bar it will dampen the effect, but take them off and away we go. A fork brace might help to equalize the rebound, but it's actually the rebound valve that may be worn out or damaged?? Tires that are out of balance, mounted incorrectly, damaged, will have the same effect as hitting a small bump. Anything that's done to dampen the effect, head bearing adjustment, fork brace, will keep things calmed down, but in the end it's the rebound valve in one or both forks that aren't doing thier job in sync. 'Cource this is just a guess.... On the earlier MkI's there is a rebound adjustment on the bottom of the Anti-dive unit. If they aren't on the same setting the forks will not work equally. On the MkII's if one of the AD's isn't working properly the forks will not work equally.

Deffinitions: --- Its not a matter of Adding Torque to the head bolt.

Its a matter, of setting the Torque to the Correct Amount. -- Which may be set

to to much torque, or not enough, ( ahemm, by the previous owner )

Springs: On a 1st Gen bike, if over 50K the Fork Springs need to be replaced .

-- Period ----

Adding the aftermarket Fork Brace, will help, but not eliminate the problem.

Ditto on the Rear Suspension comments here. Repack and Re-Torque the Swing arm.

Also, the suspension connecting Arms to the Swing arm, Lubricate those bolts.

One last comment, I know people who have gone DOWN, because of this on different motorcycles, over the years ----

This Situation can become Deadly-- Consider it a Serious matter

From what I have absorbed so far front wheel wobble can be caused by and corrected by addressing the following or a combination of the following:

 

1. Front wheel out of balance
   
2. front fender brace upgrade
   
3. tightened cinch bolts on front forks
   
4. Furbur washer fix
   
5. solid motor mount upgrade
   

Have I left anything out.

 

Question: Can it also be caused by unequal amounts of fork oil in each of the forks?

A couple of other things could be the tire is not mounted correctly, the rim is tweeked out of round, and the tire tread pattern might not be true.

I had low speed wobble in my 06 RSV in oct. my front tire had 16,000 miles on it. i put more PSI in front the wobble went to higher speed, put new Avon tire on still there , Then then i Toqure the steering Bearings that did it. Its got to be ( TOQURE ) Guys.

Because of the "linked" braking system on the First Gens. When applying the front brake lever, you are actually only activating one of the front disc brakes. I think the "Drag" on the one side only contributes to the "wobble" under braking conditions. Even when using the rear foot brake, the calipers on the front forks are two different sizes so you NEVER get even braking action on the front forks.

As Lonestarmedic mentioned I have listed the "Furbur Fix" washers in the classifieds for both First Gens. and Second Gens. I have priced these washers so everyone can address their "wobble" issues without "breaking the bank". I too feel that the front fork tubes on the First Gen. Ventures are a bit "smallish" at best, so when you compound the issue with a worn/badly ballanced tire or loose steering head bearings or worn motor mounts or a loose swing arm, or worn front springs, you push the design of the First Gen. front end into the "Wobble" zone. For me, "Delinking" the front brakes changed the wear pattern of the front tire and gave me relief from the front end wobble for an extended peroid of time (decreased right side of tire scrubbing) as well as increased the front brake stopping power without pulling to the right. IMHO I think Yamaha fell a bit short in the design of the First Gen. front end and it is so finely tuned that if only one or two items are not up to snuff then the wobble insues.

Just my thoughts,

Earl