TIRE CUPPING & DEATH WOBBLE


Technical information and Q&A applicable to all years and models of Goldwings
Post Reply
FM-USA
Posts: 3079
Joined: Wed May 18, 2011 8:40 am
Location: here, there, WHY?
Motorcycle: mc's

TIRE CUPPING & DEATH WOBBLE

Post by FM-USA »



It does not explain all the possibilities of Death Wobble
but if you have tire cupping, hopefully this info helps.





User avatar
Nlmman47
Posts: 35
Joined: Thu Mar 31, 2022 8:03 am
Location: Middlesex, NC
Motorcycle: 1993 GL1500 Goldwing Aspencad

Re: TIRE CUPPING & DEATH WOBBLE

Post by Nlmman47 »

my tire is starting to cupping now. is it just normal wear or is it a sign of something more
FM-USA
Posts: 3079
Joined: Wed May 18, 2011 8:40 am
Location: here, there, WHY?
Motorcycle: mc's

Re: TIRE CUPPING & DEATH WOBBLE

Post by FM-USA »

Tire pressure low?
Worn front wheel bearings.
Rear tire pressure low?
Loose bearings in steering stem and/or swing-arm.

Balance Beads (basically) fixed one badly cupped Battlax tire.
B.B.'s smoothed out the tire rotation and cupped tire worn evenly. Got about 5k more miles out of it.

.
User avatar
Rednaxs60
Posts: 2672
Joined: Wed Nov 18, 2015 12:44 pm
Location: Victoria, British Columbia, Canada
Motorcycle: 1985 GL1200 LTD
2014 Can-Am Spyder RT LE
1995 GL1500 SE CDN Edition (sold)
2012 Suzuki DL1000 VStrom (sold)
2008 GL1800 (sold)
Ontario 1985 GL1200 LTD (sold)

Re: TIRE CUPPING & DEATH WOBBLE

Post by Rednaxs60 »

Adding to the list. Weak/worn out suspension.
"When you write the story of your life, don't let anyone else hold the pen"

Ernest
FM-USA
Posts: 3079
Joined: Wed May 18, 2011 8:40 am
Location: here, there, WHY?
Motorcycle: mc's

Re: TIRE CUPPING & DEATH WOBBLE

Post by FM-USA »

Rednaxs60 wrote: Fri May 27, 2022 8:59 am Adding to the list. Weak/worn out suspension.
AHHhhh, right. Forgot about that.
A weak or broken spring, low fluid fork leg would/could be the culprit.

.
User avatar
WingAdmin
Site Admin
Posts: 22955
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (sold)
1998 XV250 Virago (sold)
2012 Suzuki Burgman 400 (wife's!)
2007 Aspen Sentry Trailer
Contact:

Re: TIRE CUPPING & DEATH WOBBLE

Post by WingAdmin »

I don't think cupping can be a cause of death wobble.

When a tire is cupped, it is usually a repeating left/right pattern of every 10 inches or so around the tire. Death wobble on our bikes is most prevalent at around 35 mph, particularly when decelerating. At 35 mph, the left/right cupping cycle would be hitting the ground more than 60 times per second. Death wobble is a much lower frequency oscillation, at between 4-10 times per second - it's the resonant frequency of the steering head assembly (coupled to the bike frame).

Death wobble has quite a few potential causes, but as a result of the grip loss from cupping is not going to be one of them.

Grabbing onto the handlebars lowers the resonant frequency of the handlebar system to below that which is induced by whatever is causing it. That's why death wobble often occurs when decelerating without hands on the handlebars (or only loosely holding on to them). Hold onto them firmly, that little bump won't induce the wobble, because the resonant frequency of the handlebars is too low.
User avatar
Nlmman47
Posts: 35
Joined: Thu Mar 31, 2022 8:03 am
Location: Middlesex, NC
Motorcycle: 1993 GL1500 Goldwing Aspencad

Re: TIRE CUPPING & DEATH WOBBLE

Post by Nlmman47 »

is there a way to check if it is my forks. i haven't changed the oil in them since i had it and i doubt the old rider did. i am going to change the oil soon as i get the gauge i order in. i want to make sure i get the right amount in there. i dont want to take the forks off to do that if i can help it. is there any way to check to see if it is the forks?
User avatar
newday777
Posts: 2229
Joined: Tue Jan 11, 2011 5:21 pm
Location: Milford NH summer/fall & Oceanside, CA winters(N San Diego) with lots of miles riden between
Motorcycle: 2008 Cabernet Red. Level 4

1983 GL1100A Wineberry 36,000 miles

1975 CB750 K5 Planet Blue 7,800 miles

1976 CB750 K6 Anterris Red 25,000 miles

Past rides
1999A Restored from PO neglect & sold at 19,000 miles

1999SE Totaled by cager at 105,000 miles

Re: TIRE CUPPING & DEATH WOBBLE

Post by newday777 »

Many will give you various things to do but the only cure for tire cupping and the steering wobble is to replace the steering bearing set, and properly torque them.
Steering bearings are a maintenance item that most riders fail to replace thinking "naw they don't wear out.... "
Get tapered bearings sets not round ball bearings.
User avatar
minimac
Posts: 924
Joined: Mon Aug 06, 2012 9:25 am
Location: Oswego, NY, Leesburg, Fl
Motorcycle: 1993 GL1500 Aspencade
2006 Yamaha Morphous
2011 Silverwing
Y̶a̶m̶a̶h̶a̶ ̶M̶a̶j̶e̶s̶t̶y̶
S̶u̶z̶u̶k̶i̶ ̶B̶u̶r̶g̶m̶a̶n̶ ̶E̶x̶e̶cutive

Re: TIRE CUPPING & DEATH WOBBLE

Post by minimac »

The combination of of replacing the steering head bearings and using balance beads cured my headshake and tire cupping issues.
User avatar
WingAdmin
Site Admin
Posts: 22955
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (sold)
1998 XV250 Virago (sold)
2012 Suzuki Burgman 400 (wife's!)
2007 Aspen Sentry Trailer
Contact:

Re: TIRE CUPPING & DEATH WOBBLE

Post by WingAdmin »

For cupping, anything in the front end that is loose can cause it: steering head bearings, wheel bearings, fork bushings. If the wheel can move in any other direction other than rotating or steering, then there's a good chance you're going to see cupping. It can also be caused by incorrect tire pressure, unbalanced tires and overloaded bikes.

Death wobble can be caused by so many things, it makes it very hard to track down. Anything loose or flexible, from wheel bearings to swingarm pivots can cause it.
User avatar
cbx4evr
Posts: 1484
Joined: Tue Mar 09, 2010 8:35 pm
Location: Edmonton, AB Canada
Motorcycle: 2006 Kawasaki Concours - sold - :-)
2000 GL1500SE - sold :-(
2004 Kawasaki KLR 650
Solex 5000 - gave to son
1980 Honda CBX - sold :-(
1981 Honda CBX - sold :-(
Contact:

Re: TIRE CUPPING & DEATH WOBBLE

Post by cbx4evr »

Nlmman47 wrote: Thu May 26, 2022 11:34 am my tire is starting to cupping now. is it just normal wear or is it a sign of something more

This is Dunlops response to the cupping question:

You may not be able to entirely avoid cupping. Tire cupping or irregular wear is a somewhat common occurrence on all vehicles. On a four-wheel vehicle, you are advised to rotate your tires periodically to even out wear. Unfortunately, you do not have this luxury with a motorcycle because front and rear tires, unlike those on most four-wheel vehicles, are not interchangeable.

However, there are steps that can be taken to minimize cupping and uneven wear on a motorcycle: Maintain your motorcycle and particularly your front and suspension. Avoid hard braking whenever possible. Braking causes the tire to grab and wear in one direction. When braking is applied to the front tire, the load transfer over-flexes the tire and increases the tendency for cupping and uneven wear. Maintain your tire pressures. Under inflation and overloading of motorcycle tires are significant causes of cupping and uneven wear, particularly in association with hard braking and/or trailer use.

Once a tire begins to show signs of uneven wear, even following these steps may not improve the condition.

Tire companies can, and are, helping to minimize cupping and uneven wear but you, the rider, must do your part. Following the aforementioned guidelines will help avoid uneven wear.
"It´s a friggen motorcycle, it´s not supposed to be comfortable, quiet or safe. The wind noise is supposed to hurt your ears, the seat should be hard and riding it should make you s**t your pants every now and then. "
User avatar
Nlmman47
Posts: 35
Joined: Thu Mar 31, 2022 8:03 am
Location: Middlesex, NC
Motorcycle: 1993 GL1500 Goldwing Aspencad

Re: TIRE CUPPING & DEATH WOBBLE

Post by Nlmman47 »

i just installed a fork brace. i believe its the super brace not blackwing. but it does make the front end tighter and more control of the steering. i still have the deceleration woble at 35 but it still helps on the leaning and steering. im happy with that i hope it would stop the wobble but i happy
User avatar
Sassy
Posts: 428
Joined: Thu Nov 05, 2020 12:15 am
Location: Wynndel bc canada
Motorcycle: 1989 gl1500

Re: TIRE CUPPING & DEATH WOBBLE

Post by Sassy »

WingAdmin wrote: Tue May 31, 2022 1:10 pm I don't think cupping can be a cause of death wobble.

When a tire is cupped, it is usually a repeating left/right pattern of every 10 inches or so around the tire. Death wobble on our bikes is most prevalent at around 35 mph, particularly when decelerating. At 35 mph, the left/right cupping cycle would be hitting the ground more than 60 times per second. Death wobble is a much lower frequency oscillation, at between 4-10 times per second - it's the resonant frequency of the steering head assembly (coupled to the bike frame).

Death wobble has quite a few potential causes, but as a result of the grip loss from cupping is not going to be one of them.

Grabbing onto the handlebars lowers the resonant frequency of the handlebar system to below that which is induced by whatever is causing it. That's why death wobble often occurs when decelerating without hands on the handlebars (or only loosely holding on to them). Hold onto them firmly, that little bump won't induce the wobble, because the resonant frequency of the handlebars is too low.
I disagree. When I bought my bike the tires were almost done, the front badly cupped, and had a severe wobble as soon as I let go the bars. The instant I changed the front tire with no other changes the wobble was gone. The bike didnt have a brace on it at the time and there was no detectable looseness in any suspension components front or rear.
Enjoying the 2xDarkside
Fred
User avatar
Nlmman47
Posts: 35
Joined: Thu Mar 31, 2022 8:03 am
Location: Middlesex, NC
Motorcycle: 1993 GL1500 Goldwing Aspencad

Re: TIRE CUPPING & DEATH WOBBLE

Post by Nlmman47 »

Sassy wrote: Sun Jun 12, 2022 9:06 pm
WingAdmin wrote: Tue May 31, 2022 1:10 pm I don't think cupping can be a cause of death wobble.

When a tire is cupped, it is usually a repeating left/right pattern of every 10 inches or so around the tire. Death wobble on our bikes is most prevalent at around 35 mph, particularly when decelerating. At 35 mph, the left/right cupping cycle would be hitting the ground more than 60 times per second. Death wobble is a much lower frequency oscillation, at between 4-10 times per second - it's the resonant frequency of the steering head assembly (coupled to the bike frame).

Death wobble has quite a few potential causes, but as a result of the grip loss from cupping is not going to be one of them.

Grabbing onto the handlebars lowers the resonant frequency of the handlebar system to below that which is induced by whatever is causing it. That's why death wobble often occurs when decelerating without hands on the handlebars (or only loosely holding on to them). Hold onto them firmly, that little bump won't induce the wobble, because the resonant frequency of the handlebars is too low.
I disagree. When I bought my bike the tires were almost done, the front badly cupped, and had a severe wobble as soon as I let go the bars. The instant I changed the front tire with no other changes the wobble was gone. The bike didnt have a brace on it at the time and there was no detectable looseness in any suspension components front or rear.
Did you notice a difference in the front steering and the way the front feels after you put on the brace. i notice a big difference in the front outside of the wobble. but i do need to change the tire. and maybe it will make things even better. i feel the road and every bump it has. i do need to change the fork oil and see if that helps with that. and see if i can fix my left front brake it not clamping tight, i hear it dragging when i press my foot brake.i have bleed it but maybe try it again or i will have to tear it down and see. thanks for anything you can tell me
User avatar
Sassy
Posts: 428
Joined: Thu Nov 05, 2020 12:15 am
Location: Wynndel bc canada
Motorcycle: 1989 gl1500

Re: TIRE CUPPING & DEATH WOBBLE

Post by Sassy »

To be fair the brace was installed over the winter so impressions would be a little vague with the 5 month lay up.
I believe the improvement for me is slow speed maneuvers over uneven terrain,. The front wheel felt as if it followed the terrain more without the brace causing me to put a foot down more often.
I dont know what if any maintenance has been done on the front suspension but tire and brace made the front feel rock solid on a 33 year old bike with 200,000k.
Enjoying the 2xDarkside
Fred
FM-USA
Posts: 3079
Joined: Wed May 18, 2011 8:40 am
Location: here, there, WHY?
Motorcycle: mc's

Re: TIRE CUPPING & DEATH WOBBLE

Post by FM-USA »

Sassy wrote: Sun Jun 12, 2022 9:06 pm
WingAdmin wrote: Tue May 31, 2022 1:10 pm I don't think cupping can be a cause of death wobble.

When a tire is cupped, it is usually a repeating left/right pattern of every 10 inches or so around the tire. Death wobble on our bikes is most prevalent at around 35 mph, particularly when decelerating. At 35 mph, the left/right cupping cycle would be hitting the ground more than 60 times per second. Death wobble is a much lower frequency oscillation, at between 4-10 times per second - it's the resonant frequency of the steering head assembly (coupled to the bike frame).

Death wobble has quite a few potential causes, but as a result of the grip loss from cupping is not going to be one of them.

Grabbing onto the handlebars lowers the resonant frequency of the handlebar system to below that which is induced by whatever is causing it. That's why death wobble often occurs when decelerating without hands on the handlebars (or only loosely holding on to them). Hold onto them firmly, that little bump won't induce the wobble, because the resonant frequency of the handlebars is too low.
I disagree. When I bought my bike the tires were almost done, the front badly cupped, and had a severe wobble as soon as I let go the bars. The instant I changed the front tire with no other changes the wobble was gone. The bike didnt have a brace on it at the time and there was no detectable looseness in any suspension components front or rear.
I expect Scott to remove your post like he did mine soon.
Folks like you & I have experiences that's NOT in his realm of experience he posts very long explanations to support HIS theory and try to prove your/ours wrong.
BUT... it's his website, he's the dictator of it.

.
User avatar
Sassy
Posts: 428
Joined: Thu Nov 05, 2020 12:15 am
Location: Wynndel bc canada
Motorcycle: 1989 gl1500

Re: TIRE CUPPING & DEATH WOBBLE

Post by Sassy »

Well FM that doesn't change the truth.
Ive always respected Scotts input, videos and totorials plus really like the site and people on it.
Ive had different experiences on repairs or changes and posted them in the relatively short time I've been on the forum and don't recall any issue.
Enjoying the 2xDarkside
Fred
User avatar
Rambozo
Posts: 1685
Joined: Sun Apr 01, 2018 8:36 pm
Location: Disneyland
Motorcycle: 1992 GL1500 Aspencade
Ducati Monster

Re: TIRE CUPPING & DEATH WOBBLE

Post by Rambozo »

If your tire is cupping, something is wrong. That is not normal wear.
User avatar
WingAdmin
Site Admin
Posts: 22955
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (sold)
1998 XV250 Virago (sold)
2012 Suzuki Burgman 400 (wife's!)
2007 Aspen Sentry Trailer
Contact:

Re: TIRE CUPPING & DEATH WOBBLE

Post by WingAdmin »

FM-USA wrote: Wed Jun 22, 2022 1:54 pm I expect Scott to remove your post like he did mine soon.
Folks like you & I have experiences that's NOT in his realm of experience he posts very long explanations to support HIS theory and try to prove your/ours wrong.
BUT... it's his website, he's the dictator of it.

.
I do not remove posts I disagree with.

The ONLY time posts have been removed is when they are extremely inflammatory or argumentative/wholly offensive.
joecoolsuncle
Posts: 383
Joined: Sun Sep 26, 2021 6:10 am
Location: oxford, ar
Motorcycle: 1984 gl1200a

Re: TIRE CUPPING & DEATH WOBBLE

Post by joecoolsuncle »

WingAdmin wrote: Thu Jun 23, 2022 4:42 pm
FM-USA wrote: Wed Jun 22, 2022 1:54 pm I expect Scott to remove your post like he did mine soon.
Folks like you & I have experiences that's NOT in his realm of experience he posts very long explanations to support HIS theory and try to prove your/ours wrong.
BUT... it's his website, he's the dictator of it.

.
I do not remove posts I disagree with.

The ONLY time posts have been removed is when they are extremely inflammatory or argumentative/wholly offensive.
unlike other forums. like something ending with facts. i find this one of the most honest and factual forums available.
User avatar
WingAdmin
Site Admin
Posts: 22955
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (sold)
1998 XV250 Virago (sold)
2012 Suzuki Burgman 400 (wife's!)
2007 Aspen Sentry Trailer
Contact:

Re: TIRE CUPPING & DEATH WOBBLE

Post by WingAdmin »

joecoolsuncle wrote: Thu Jun 23, 2022 5:48 pm unlike other forums. like something ending with facts. i find this one of the most honest and factual forums available.
That's actually the reason GoldwingDocs exists. I got tired of most of my posts on the "Facts" website being deleted by obnoxious admins who had taken a personal dislike to me, so I created my own website.
FM-USA
Posts: 3079
Joined: Wed May 18, 2011 8:40 am
Location: here, there, WHY?
Motorcycle: mc's

Re: TIRE CUPPING & DEATH WOBBLE

Post by FM-USA »

Well a post of mine in this thread was removed. It has MY experience which is FACT.
If there was something inflammatory maybe either I be informed of it or THAT part removed and I still be informed as to why.
We're all here to learn... good, bad or ugly.

BTW: This isn't the 1st time a post of mine was removed in GWD. Not counting one I requested deleted. That whole thread went bad and it was in your best interest, Scott, to just get rid of it.

I'm not here to disparage anyone but I couldn't miss the 39 'Thumbs Down' without reason(s).
I expect a few T.D. since I do things on my Wing that few would even attempt or think of trying.
But if my experiences aren't up to this sites standards...

.
FM-USA
Posts: 3079
Joined: Wed May 18, 2011 8:40 am
Location: here, there, WHY?
Motorcycle: mc's

Re: TIRE CUPPING & DEATH WOBBLE

Post by FM-USA »

Sassy wrote: Thu Jun 23, 2022 7:28 am Well FM that doesn't change the truth.
Ive always respected Scotts input, videos and totorials plus really like the site and people on it.
Ive had different experiences on repairs or changes and posted them in the relatively short time I've been on the forum and don't recall any issue.
Thanks Sassy, no it won't change truth.
Scott's input I too respect, 99% of it. There's always an IRK somewhere.


.


Post Reply