StromTrooper banner

1 - 20 of 40 Posts

·
Premium Member
Joined
·
2,953 Posts
Discussion Starter #1 (Edited)
Over the last couple of months we've had a few threads on the decel wobble that some people have experienced. Typically when coasting down between 50 and 35, if you take your hands off the bars some Stroms will go into a bar shaking frenzy. Even with hands on the bars sometimes you feel the pulsing in that speed range.
There are two main schools of thought on the cause, one being tires and the other steering head bearings.
My history with this so far:
Bought the bike new in Oct '06. No issues with stock tires. Shortly after purchasing put in better fork springs and oil. No wobble before or after. At 6500 miles put on a Battle Wing rear tire. No wobble. At 10,000 put on a set of Avon Distanzas for Alaska trip. No wobble. At 16,000 miles in Anchorage put on a set of Tourances. Immediately the front felt "funny" and "loose". Actually stopped twice between Anchorage and Valdez to pull out tools and double check all bolts. Everything was fine, but the bike still felt a little odd. It got worse as the miles added up. Back in OKC at 22,000 put the rear Battle Wing back on to use it up. No change in the feel and wobble, which had become more pronounced. At about 26,000 put a Pilot Road 2 on the back. No change in the wobble. Since the Pilot didn't come in a 19" for the Strom at 29,000 I put on a Conti Road Attack. I was REALLY excited about getting rid of that damn Tourance, since I thought the wobble would go with it. Much to my surprise, it was just as bad!
Double checked everything on the bike, steering head bearing, swingarm pivot, shock linkage...no problems...but still the decel wobble, getting worse.
Today, I put on a set (front and rear) of Pilot Road 3s. Unbelievable difference. Bike is rock solid, turns in great, feels balanced and secure.

I have not touched the steering head bearings in the whole time I've owned the bike, every time I check them they're fine. The one variable that the wobble seems to be associated with is the front tire. Certain ones are bad, and as they wear they get worse. The two that seems to get mentioned the most are the Tourance and the Road Attack, and that certainly correlates with my experience.

FWIW, YMMV, and all that. :)
 

·
Premium Member
Joined
·
3,145 Posts
I'm thinking that it's more to do with the tires. Different brands have different carcass sizes, for the same rated size, for example: 110/80".

One brand's 110/80 will have a totally different overall physical size [circumference, width, height, volume] than another brand's 110/80 size tire. I'm thinking that the tires that have a larger casing volume [namely more 'height'] might be less prone to the wobbles because they keep the front end up a touch higher than a same sized, but lower profile/lower volume tire. Then you have to factor in, is the tire profile more triangle shaped, round shaped, or 'square' shaped.......lots of factors that the size on the sidewall cannot tell you. This information is very difficult to glean from manufacturer websites, dealers, etc....only real world experience and comparison will aid you here [can be expensive with moto tires!]. And then there's the confounding variable of tire air pressure.....

While my experience with moto tires is limited [I tend to keep them on till they wear down to the nubs], I've noticed drastic handling differences in many, many mountain bike tires (comparatively inexpensive which lends to the creation of my hypothesis) of varying brands, that have the same exact size numbers on the sidewall - I swap em out all the time, and the handling characteristics couldn't be more distinctive, even though the sidewalls all say they're the exact same size (numerically). I'm thinking it all boils down to the carcass size and profile, irrespective of what the tire manufacturer states on the sidewall.

Or, ya could just keep one hand on the handlebars instead of no hands clown ridin' it!

Seems to keep the decelleration wobbles at bay with my well worn BattleWing front tire!
 

·
Registered
Joined
·
1,959 Posts
My wobble always goes away with a new front tire no matter the brand, then promptly returns when the tire is about half spent. For that reason alone I have never suspected the steering head bearings to be the cause of my wobble. It still could be that it causes the tires to wear in such a way as to create the wobble--who knows.

I've had the wobble for most of the summer. I just replaced my front and rear Battle Wings with Dunlop Trail Attacks. Wobble is gone (as usual with fresh rubber) and so far I'm really liking the TA's. Time will tell if they end up wobbling too (I suspect they will).

On this last tire change out, I decided that I'm not going to try to squeeze as much life out of the tires, especially the front. If I'm half way through the front tire and the wobble starts-I'm putting on a fresh one. If I'm lucky, the new TA's will last longer before the wobble starts. If I'm really lucky, the TA's will solve the wobble (not counting on it!)
 

·
Administrator
Joined
·
13,693 Posts
My suspicion is that the less pointed or flatter the front tire profile, the more pronounced the effect is. I suspect the root of it is a minor misallgnment of the wheels and the flatter profile causes little side forces that cause the front to act like caster wheels o na shopping cart.

In my case the wobble was completley and totally cured by putting in tapered roller bearing in the front.

..Tom
 

·
Registered
Joined
·
285 Posts
i had the same issue with a 2002 tiger i had...back in 2002.
it came with tourances. when the tourances were replaced with
d607's the wobble left. i have a little wobble, on the dl, with the death wing
and also have a set of rp3's waiting to go on.
 

·
Registered
Joined
·
34 Posts
I had Continental Road Attacks and they wobbled between 40-30MPH dealt with it for 10k miles put Michelin Anakees II wobble gone can let go of handle bars no more wobble. No wobble with the stock Bridgestones for 10k miles.
 

·
Registered
Joined
·
84 Posts
Thank you for your post Rich D.
Im thinking of getting Pilot 3 as my next tire. Posts like yours just make me more confident that it will work for me too . 2years ago I bought Continental TA front but it was wose then stock tire. So now I want to make better decision.Please Let us know how they handling as they wear out.
 

·
Premium Member
Joined
·
8,025 Posts
The reality is that tires and steering head bearings can both cause the wobbly problem.
 

·
What Kinda Bike Is That?
Joined
·
5,522 Posts
The reality is that tires and steering head bearings can both cause the wobbly problem.
Certain tires, (make and model, and worn tires), exacerbate the problem for poorly engineered, and loose, steering head bearings.
 

·
FORUM GODFATHER.....R.I.P. PAT
Joined
·
38,104 Posts
Certain tires, (make and model, and worn tires), exacerbate the problem for poorly engineered, and loose, steering head bearings.
Certain tires wobble on bikes with good and well set up steering head bearings. My bike wobbled with two different Conti RA front tires but not the Trail Wings or Dunlop 607s before or the same Dunlop 607 or Michelin Pilot Road afterward.
 

·
Premium Member
Joined
·
8,025 Posts
Certain tires wobble on bikes with good and well set up steering head bearings. My bike wobbled with two different Conti RA front tires but not the Trail Wings or Dunlop 607s before or the same Dunlop 607 or Michelin Pilot Road afterward.
Yeah, I think we've all had good and bad tires when it comes to this, but if you tighten the bearings slightly, the wobble will go away. I went in there five times and made very minor adjustments until it stopped.


Oh those bones, oh those bones,
oh those skeleton bones.
Oh mercy how they scare!

With the toe bone connected
to the foot bone,
and the foot bone connected
to the ankle bone,
and the ankle bone connected
to the leg bone.
Oh mercy how they scare!
 

·
What Kinda Bike Is That?
Joined
·
5,522 Posts
Certain tires wobble on bikes with good and well set up steering head bearings. My bike wobbled with two different Conti RA front tires but not the Trail Wings or Dunlop 607s before or the same Dunlop 607 or Michelin Pilot Road afterward.
Was this before, or after your upgrade to tapered, steering head roller bearings?

(I have a scheduled ride to do tomorrow. I hope that when I return, that I will have enough time in my day to upload a video to YouTube to illustrate my opinion on this matter.)
 

·
Registered
Joined
·
3,906 Posts
Based on testimony, tightening the oem bearings or replacing with tapered just masks the problem.

V-Toms post has real merit, and agrees with most of what's been discussed on this topic.
 

·
What Kinda Bike Is That?
Joined
·
5,522 Posts
Based on testimony, tightening the oem bearings or replacing with tapered just masks the problem.

V-Toms post has real merit, and agrees with most of what's been discussed on this topic.
I disagree.

Replacing the steering head bearings with, (properly adjusted), tapered bearings WILL make this phenomenon go away; no matter what tire you choose to ride on.

Ozart, have you upgraded to tapered roller bearings?
 

·
Premium Member
Joined
·
8,025 Posts
Based on testimony, tightening the oem bearings or replacing with tapered just masks the problem.

V-Toms post has real merit, and agrees with most of what's been discussed on this topic.
It's a system and all parts work together. Yes, it's the tires, and yes it's the bearings, but you can adjust the bearings, you can't adjust the tires.

I spent the bucks on the $uzuki tool because I know I'm probably gonna need it every time I try a new tire. I figure it's a question of tuning, but what can I say, I tune church organs for a living.
 

·
FORUM GODFATHER.....R.I.P. PAT
Joined
·
38,104 Posts
Was this before, or after your upgrade to tapered, steering head roller bearings?
Before, but the ball bearings were properly adjusted and in good shape. I'll buy the idea of a combination of the two items, but that makes both culprits that cause a problem wherever the combination overlaps. Tapered rollers are better than balls and Tourance or Conti tires are less stable than others.
 

·
Premium Member
Joined
·
4,199 Posts
What kind of mileage are you folks replacing the bearings?

My 09 just turn 15K a while back. I haven't experienced any wobble as yet.

Does a fork brace make any difference?
 

·
Premium Member
Joined
·
301 Posts
Something I have noticed on my VFR and then on my Wee.

The shop I used to install my tires put all the balancing weights on the LH side of the rim. On the Viffer, I kept feeling this rumble at higher speeds (70+) through the bars and when I would let go of the bars at low speed they would just shake. Then I saw how the weights were put on the wheel. I moved half of them (there were 4 - 0.5 oz weights in total) to the RH side of the wheel. Problem was gone.

I checked my front wheel on the Strom and it had 5 0.5 oz weights on the front and they were all on the LH side of the wheel. Took it for a slow spin down the street and let go fo the bars and saw the shake. Moved 2 of the the weights over to the other side of wheel and took a third and placed it in the center of the wheel rim (tough to do with the shape). No more wobble.

In each case the tire/wheel assembly was in static balance but once it starts to spin it was dynamically unbalanced due to having all the weights on one side. The wider the tire/rim combination the worse this gets.

I know from my experience in the automotive that certain cars and suspensions are more sensitive to dynamic balance than others. I also know that a tire's balance will change as it wears. Often times we dealt with customers who said though there was something wrong with the car due to a vibration and all that was done to fix it was to re-balance the tires. We ran a few controlled tests on various cars and saw that usually by 15000 miles the tires balanced point changed enough that some vehicles would see a vibration due to a dynamic imbalance on the tire.
 

·
What Kinda Bike Is That?
Joined
·
5,522 Posts
I know from my experience in the automotive that certain cars and suspensions are more sensitive to dynamic balance than others. I also know that a tire's balance will change as it wears. Often times we dealt with customers who said though there was something wrong with the car due to a vibration and all that was done to fix it was to re-balance the tires. We ran a few controlled tests on various cars and saw that usually by 15000 miles the tires balanced point changed enough that some vehicles would see a vibration due to a dynamic imbalance on the tire.
It was for this reason, a few years ago, that I switched from the typical wheel mounted weights, to an internal, "dynamic" balancing product. (Dynabeads)

However, the addition of Dynabeads caused another issue. Twice, when I attempted to check tire pressure, a "bead" got caught in the valve stem; forcing it open. I had to remove the valve core, remove the bead from the valve, reinstall the valve, and inflate the tire. All on the side of the road!

I decided to do away with using Dynabeads. I also decided to do away with any form of balancing my tires. I mount the tire on to the wheel, (If the tire has a "dot" on its sidewall; a light spot; I will place that next to the valve stem.), and mount the wheel assembly on to the bike, and ride it.

With my current setup, (unbalanced wheel/tires, and tapered roller bearings), I don't experience decel wobble, or vibration issues that other riders mention. I DID have wobble issues prior to installing tapered roller bearings. And, I DID have wobble issues after installing the tapered bearings as well! But, I spent a solid afternoon playing around with different tensions and discovered that a 1/4 turn can make a big difference!

Thank you for your post.

B.L.

PS: The bike DOES have a vibration issue at around 83mph and above. That is because both of my rims are slightly bent due to some rough riding. I like to think of it as my built in radar detector; "Time to slow down, Barry."
 
1 - 20 of 40 Posts
Top