Grumpy
Well-known member
How do you get that kind of tire mileage? I'm lucky to get 4,000 miles. The last rear lasted less than 2,000 when I was trying to keep Ashe in sight.
death wobble
- Thread starter muddiver
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RadioHowie
I Miss Beemerdons!
Easy....I pretend I'm driving a Gen II. :rofl:
See....there's your problem! Put a big-*** car tire back there and you won't be wearing it out for about 3 years!
road runner
Well-known member
You may want to check the fork pinch bolts, and the rear swing arm axle pinch bolt.
Make sure neither the forks or swing arm are being pulled in by the axle.
I've seen some guys use the pinch bolts to hold the axle from turning while tightening the axle. This may pull the fork or swing arm in, putting them were they don't want to be, and the bike can do some weird ****.
With the weight off the tire loosen the pinch bolts, tighten the axle, then make sure the forks or swing arm moves to it's relaxed position, then tighten the pinch bolts.
Make sure neither the forks or swing arm are being pulled in by the axle.
I've seen some guys use the pinch bolts to hold the axle from turning while tightening the axle. This may pull the fork or swing arm in, putting them were they don't want to be, and the bike can do some weird ****.
With the weight off the tire loosen the pinch bolts, tighten the axle, then make sure the forks or swing arm moves to it's relaxed position, then tighten the pinch bolts.
GalaxyBlue
Well-known member
Weird, But when i saw this thread title, I instantly thought Jeep.
And yeah, I agree with the m*****, It's the tires!
And yeah, I agree with the m*****, It's the tires!
copron
Well-known member
Sorry.......being able to type large letters on a computer does NOT replace the ability to perform preventative repairs. If you prefer to utilize the wobble as a tire wear indicator by all means continue. However, I find that condition unacceptable and strive to eliminate it on all bikes I own............just sayen'.
@copron - It's not quite that simple. Front tires cup. They cup faster or more severely under some conditions, such as low tire pressure, tire design, downhill braking into corners, etc.Sorry.......being able to type large letters on a computer does NOT replace the ability to perform preventative repairs. If you prefer to utilize the wobble as a tire wear indicator by all means continue. However, I find that condition unacceptable and strive to eliminate it on all bikes I own............just sayen'.
Some tires, like the BT-020 and 021 are notorious for cupping early and in ways that induce decel wobble, and eventually wobble at any speed. A little low pressure and a twisty downhill road and you can trash a tire, cupped to the point where it really sucks to ride it, in a single ride. And I'm not talking about a long ride either, just a 100-200 mile ride under poor conditions can do that.
Frankly, you're not paying attention. And you're mistaken about decel wobble being head bearings "almost always". Tire issues are far more common for decel wobble with FJRs. And, need I point out that the OP had the head bearings adjusted by the shop with no change in conditions. Also note that the OP never did tell us what tire he was using or what pressure he was riding with. 1k miles since "last Fall" does make me wonder how religious he is about checking tire pressure before rides. Also noted is that the problem didn't show up until after a tire change, and previously did not exist, at least to the owner's knowledge.
@Grumpy - It's all in the wrist. Sharp accel and hard decel wear tires. Temps and surface conditions certainly affect things too, but mostly it's just in the wrist. Smooth is fast.
RadioHowie
I Miss Beemerdons!
Not really. Smooth means carrying more speed into the corner and through it, instead of braking hard into and hammering out of the corners. Keep in mind, I'm speaking of street riding, not track riding. Track riding means you are on the throttle or on the brakes all the time. You never just cruise.I think you meant to say.....Smooth isfastfrugal.
Well it could be tires, or steering head, or lots of things. Since new, my 05's front end would never "wobble" with hands off of the handle bars, even when decelerating down through the 50-45 mph range.
But after the local dealer repacked the steering head bearings per Yamaha's maintenance schedule, it often does exactly that! The same tire was on the bike before and after this service. When I picked the bike up, I mentioned to the mechanic that Yamaha specs a special tool for torquing the front steering bearings. He said, "Yamaha has a special tool for everything." Obviously he followed his own procedure and not the factory's.
I suspect that, in this particular instance, it was just not torqued correctly. But it's only a slight annoyance, so I suppose I'll get around to fixing it some day.
But after the local dealer repacked the steering head bearings per Yamaha's maintenance schedule, it often does exactly that! The same tire was on the bike before and after this service. When I picked the bike up, I mentioned to the mechanic that Yamaha specs a special tool for torquing the front steering bearings. He said, "Yamaha has a special tool for everything." Obviously he followed his own procedure and not the factory's.
I suspect that, in this particular instance, it was just not torqued correctly. But it's only a slight annoyance, so I suppose I'll get around to fixing it some day.
OK, let's think about this:
The only way that a steering head bearing will cause, or more accurately prevent, wobble is if the preload on the bearing is such that it provides mechanical dampening to the oscillating forces that are always present. Kind'a like keeping your hands on the handlebars will.
In other words, the bearings can not be the root cause of the wobbles, however they can contribute to wobble occurring by being too loose.
The root cause has to be something that is actually moving, so it is most likely caused by some part of the rotating mass of the wheel(s).
Since it is impossible to achieve 100% perfect balance on wheels, and since tires will always have some degree of imperfection, having some (small) amount of dampening in the steering head bearings would help eliminate oscillation.
If all of the front wheel variables have been checked and rechecked, then adding preload to the steering bearing may kill the wobbles. The reason a roller bearing would also work is it has more contact area, therefore more friction and more dampening for the same amount preload torque. Plus they can withstand higher preload (for even more dampening) than ball bearings, without distorting the races.
At some point too much preload of the steering bearings will result in handling issues since it will require too much effort to turn the bars to initiate steering. And, especially with balls, may cause premature wear and dimpling of the bearing races which results in notchy (varying) resistance to steering input.
So, both the "tires/wheels" group and the "steering head bearing" group may both be right here.
The only way that a steering head bearing will cause, or more accurately prevent, wobble is if the preload on the bearing is such that it provides mechanical dampening to the oscillating forces that are always present. Kind'a like keeping your hands on the handlebars will.
In other words, the bearings can not be the root cause of the wobbles, however they can contribute to wobble occurring by being too loose.
The root cause has to be something that is actually moving, so it is most likely caused by some part of the rotating mass of the wheel(s).
Since it is impossible to achieve 100% perfect balance on wheels, and since tires will always have some degree of imperfection, having some (small) amount of dampening in the steering head bearings would help eliminate oscillation.
If all of the front wheel variables have been checked and rechecked, then adding preload to the steering bearing may kill the wobbles. The reason a roller bearing would also work is it has more contact area, therefore more friction and more dampening for the same amount preload torque. Plus they can withstand higher preload (for even more dampening) than ball bearings, without distorting the races.
At some point too much preload of the steering bearings will result in handling issues since it will require too much effort to turn the bars to initiate steering. And, especially with balls, may cause premature wear and dimpling of the bearing races which results in notchy (varying) resistance to steering input.
So, both the "tires/wheels" group and the "steering head bearing" group may both be right here.
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beemerdons
Certifiable Old Fart
Very Well Stated, FredW! Best and most accurate analysis yet on our FJR's and their wobbles! I only thought our RadioHowie used the largest letters because he is such an OLD FART!
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Bustanut joker
Well-known member
It also helps old feckers like you to read ****..
Damn it man! Do I have to explain everything to ya?
:jester:
charismaticmegafauna
Well-known member
And..., some brands, models, types of bikes never exhibit a front end wobble -- you could ride all day with your hands off the bars if you wanted to -- so chassis geometry/weight loading must have some validity...
+1 - It's the chassis geometry, specifically steering angle, that make a bike stable or non stable. It's also a trade off for being responsive or sluggish steering. More responsive (quicker) steering bikes generally have less caster (steeper steering angle) and are more susceptible to oscillations.
But the steering caster is pretty much fixed by the design engineers. Yeah, you can change the angle somewhat via varying suspension pre-loads (both front and back) or by sliding the fork tubes up or down in the triple trees.
But the steering caster is pretty much fixed by the design engineers. Yeah, you can change the angle somewhat via varying suspension pre-loads (both front and back) or by sliding the fork tubes up or down in the triple trees.
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luxrybound
Well-known member
I will vote the head bearings. I ride a honda vtx till Sat then I get my 09 fjr But with the vtx you could let go of the bars and it would wobble bad (scary). I replace the bicycle head bearings with all ball bearings and the problem was gone. New tire or old worn tire it never showed up again.I put 28000 miles in 1 1/2 years and never had the problem after replacing So I vote head bearings
Oh geeze... I give up.
You're right, it's the bearings.
You're right, it's the bearings.
RadioHowie
I Miss Beemerdons!
Yeah...I gave up about 11 posts back.Oh geeze... I give up.
You're right, it's the bearings.
TownsendsFJR1300
Well-known member
I developed the de-cel wobble when the original Bridgestone on the front wore out (cupped badly). A new tire solved the problem.
On my old 2004 Goldwing, it also developed a de-cel wobble. The bike used regular roller bearings for the steering head. I had the dealership replace them with the tappered "All Balls Bearings" (see below link) highly recomended in the GW community, the tires were still good. Replacing the bearings alone solved the de-cel problem, period. Yes a different, heavier bike but I wouldn't rule them out completly. If their worn or not adjusted correctly they will cause problems.
https://www.directlineparts.com/product.asp...=4429&str=4
The customers reviews are also enlightening.
On my old 2004 Goldwing, it also developed a de-cel wobble. The bike used regular roller bearings for the steering head. I had the dealership replace them with the tappered "All Balls Bearings" (see below link) highly recomended in the GW community, the tires were still good. Replacing the bearings alone solved the de-cel problem, period. Yes a different, heavier bike but I wouldn't rule them out completly. If their worn or not adjusted correctly they will cause problems.
https://www.directlineparts.com/product.asp...=4429&str=4
The customers reviews are also enlightening.
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charismaticmegafauna
Well-known member
Which one, then, would you recommend to the O.P.? (or both...?)
And..., what kind of steering head bearings did your old Gold Wing have installed (before the "All Balls") that were bad?
"regular roller bearings" (ball bearings or radial, non-thrust, roller bearings)?
TownsendsFJR1300
Well-known member
Which one, then, would you recommend to the O.P.? (or both...?)
And..., what kind of steering head bearings did your old Gold Wing have installed (before the "All Balls") that were bad?
"regular roller bearings" (ball bearings or radial, non-thrust, roller bearings)?
The Goldwing had roller bearings, just like the FJR. The Goldwing, to my knowledge has not changed them although its a known problem, MUCH more so than the FJR. It should be noted that I checked for play/drag in the Goldwing both before and after the bearings were changed out (at the dealership). No play/slop was detectedwith either bearing however the tappered bearing fixed the problem. The dealership, ("Haps" in Sarasota, Florida), prior to doing the work, highly recomended the tappered bearings as the fix and does them all the time.
Its my understanding that with the tappered bearings there's more surface area (with the longer bearing) connecting the steering assembly to the frame.
If it was my bike and the new front tire (or any other fixes didn't help), I personally would replace the steering head bearings with the tappered, "All Balls Bearings" (especially after tightening up the regular steering heads bearings helped some)...
Just looking on-line, they are available for the FJR: https://www.bikebandit.com/all-balls-motorc...mp;t=1&td=1
Hope this helps, Scott
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