Harley death wobble

[Westernbiker]

Anyone experience this on your Valk? I know I haven't and I have had the Valks I have owned as fast as they will go. I suppose all bikes may do this depending on maintenance and other issues, IE steering head bearings, swingarm bearings or shock bushings maybe? Must be a terrible experience. Can anyone relate?

http://www.kpho.com/news/27917754/detail.html

[Serk]

Sounds like a "Tank Slapper" to me, which is not isolated to Harleys (Although I've never had one on my Valk *Knock on wood*)

http://en.wikipedia.org/wiki/Speed_wobble

[Motorcycle Accident]TT-Tankslapper-19sec	powered by Aeva

TANKSLAPPER! MAM 6/28/10	powered by Aeva

robs tank slapper	powered by Aeva

[hubcapsc]

My buddy Randy got into what he described as pretty much a tank slapper while passing a
big truck on the Interstate... turned out he had loose spokes... he has non-spoke wheels
now 



-Mike

[Rowdy]

  Had that happen once on my Valk I/S  5 years ago or so
I was trying to avoid a trash can that was being sucked accros the road by a passing truck, I think I may have hit to much front brake at the same time I was trying to lean away from the trash can, going about 50 mph - it started that tank slap  I thought I was a gonner, but I got her back under control 

[toetruck21]

Had that happen once on my Valk I/S  5 years ago or so
I was trying to avoid a trash can that was being sucked accros the road by a passing truck, I think I may have hit to much front brake at the same time I was trying to lean away from the trash can, going about 50 mph - it started that tank slap  I thought I was a gonner, but I got her back under control 

Just got done taking the motorcycle safety course, was tought you are never to use your front brake in a swerve maneuver or in a lean.  Always raise bike to vertical position before using the front brake!  Just thought I would pass that on.  I only paid $200 for that little bit of info.

[Bobbo]

I think many of these "tank slapper" events are similar to what's called PIO (Pilot Induced Oscillation) in aircraft lingo.  The rider is subconsciously or consciously trying to fight the oscillation, and is actually adding to it.

[RoadKill]

My Valk was a tank slapper over 100 mph after changing out the Metzler rear tire it came with.I ran several Dunflop MC tires and it would sway more than "slap", after I went DS it was worse especially with lower than optimum air pressure. Changed to Bridgestone cartire and keep it aired up solid...42 or more and she has no sway or slap/shake even with almost non existent shock bushings and slightly bent frame  

[G-Man]

Had that happen once on my Valk I/S  5 years ago or so
I was trying to avoid a trash can that was being sucked accros the road by a passing truck, I think I may have hit to much front brake at the same time I was trying to lean away from the trash can, going about 50 mph - it started that tank slap  I thought I was a gonner, but I got her back under control 

Just got done taking the motorcycle safety course, was tought you are never to use your front brake in a swerve maneuver or in a lean.  Always raise bike to vertical position before using the front brake!  Just thought I would pass that on.  I only paid $200 for that little bit of info.

This is true no matter how slow you are going.  I was slowing down to enter a gas station and the bike was in a slight lean.  I couldn't have been going more than 10 mph.  I saw a lot of gravel approaching and hit the front brake to try and stop before I reached the gravel and it just made the bike slide right out.  I layed her down and did a bit of a body roll as I left the seat.  No injuries and only knocked off a highway peg.  Bike was resting on the crashbar.  A guy ran over and helped me get her upright and said that he couldn't believe I went down because I was going so slow.  Front brake and sand was all it needed.

[bigvalkriefan]

Just this Sunday I decided to open her up on a lonely isolated stretch and got to 115 indicated. She started a to sway back and forth.  I slowly let off throttle and it stopped when I got under 100. I'm thinking it had to do with the wind hitting my sail of a windshield, but hey, I'm no expert.

[Stanley Steamer]

I only had it happen once at 124mph GPS actual speed...indicated at over 130mph on the speedo...long, downhill run....had just passed two Hardleys and was headed home from a VRCC ride.....got my butt up off the seat, eased down on the BACK brake, held the handlebars REALLY tight to keep the handlebars from slapping the tank....it was like a giant hand had hold of me and was moving the bike left and right....had a big right hand curve at the bottom of the hill....all I was thinking was that this is going to hurt..... ....thankfully I got enough speed off to where I got the bike under control again.....never even bothered me much at the time....but it should have!!!!

[Westernbiker]

I only had it happen once at 124mph GPS actual speed...indicated at over 130mph on the speedo...long, downhill run....had just passed two Hardleys and was headed home from a VRCC ride.....got my butt up off the seat, eased down on the BACK brake, held the handlebars REALLY tight to keep the handlebars from slapping the tank....it was like a giant hand had hold of me and was moving the bike left and right....had a big right hand curve at the bottom of the hill....all I was thinking was that this is going to hurt..... ....thankfully I got enough speed off to where I got the bike under control again.....never even bothered me much at the time....but it should have!!!!

Am curious to know PUCKER FACTOR on that one?

[DFragn]

Had it a 100mph +. It heated up the front tire well enough for both me & buddy, behind in the right lane, to smell the rubber.

It started occurring more & more regularly at lower speeds. Got to be I needed to stay awake at 60mph. Apparently, rough road surfaces and Big Rig wind vortexes would easily initiate it.
Joanne once was following in the cage on Chicago Tollway and witnessed my rear tire moving side-to-side about 2" overall as I accelerated to change lanes at 70mph. I was feeling it a bit before I moved over, but just as I crossed a parallel pavement joint all hell broke loose. Amazing how fast traffic backed away from me. Scrubbed the speed down to about 50mph & it partially stabilized for the rest of the ride home.

It took me over a year to isolate the cause. - Swing Arm Bearings - I replaced and torqued properly and haven't had an issue in 15k miles.
There were 70k miles on those bearings. I'm assuming they weren't properly torqued from the factory.

Did I need to replace them or would have re-torquing been sufficient?
Well, once you've experienced Tank Slap you want to be sure you've eliminated it.

[Hoser]

Had a Kawasaki Z1 back in the seventies, would start shakin everytime I went over 115,  I think it was standard equipment for the early ones.  It would stop if ya grabbed some front brake and chopped the throttle  back.  Worked every time I needed it.  Hoser  

[DFragn]

Had a Kawasaki Z1 back in the seventies, would start shakin everytime I went over 115,  I think it was standard equipment for the early ones.  It would stop if ya grabbed some front brake and chopped the throttle  back.  Worked every time I needed it.  Hoser  

Chopping the throttle back while only shakin' might be OK. But, I know for sure with the slappers I had I would've been on the pavement at 100mph if I hadn't not panicked and gradually reduced my speed with the throttle only. Under those conditions any abrupt speed change is likely to hurt you.

[Stanley Steamer]

I only had it happen once at 124mph GPS actual speed...indicated at over 130mph on the speedo...long, downhill run....had just passed two Hardleys and was headed home from a VRCC ride.....got my butt up off the seat, eased down on the BACK brake, held the handlebars REALLY tight to keep the handlebars from slapping the tank....it was like a giant hand had hold of me and was moving the bike left and right....had a big right hand curve at the bottom of the hill....all I was thinking was that this is going to hurt..... ....thankfully I got enough speed off to where I got the bike under control again.....never even bothered me much at the time....but it should have!!!!

Am curious to know PUCKER FACTOR on that one?

Pucker factor was HIGHHHHH at THAT moment....a couple of miles down the road, I was A-ok.....never did see those Hardley boys again......

One other HIGH pucker factor moment was when I passed a row of 10-12 Hardleys on a long, STEEP, uphill straight away.....it was on HWY 17 South between Hollywood and Toccoa GA....I got some speed up on the downhill straightaway...pulled out to pass at the bottom of the V, and passed the leading Hardley in 4th gear at about 105mph.....only problem was that 3/4's of the way UP the long straightaway, the hill wasn't as steep and I couldn't see if anyone was headed DOWN the hill..... .....That one got my attention.....I didn't back off and twisted the wick even further....not sure how fast I was going on the top of the hill......the Man above must favor FOOLS......

[chrise2469]

I get a slight wobble around 185 KM/hr with the avons.  When I had the dunlops I had a slight wobble around 210.  I've had new bushings, shocks and bearings with no change.

I figure its due to the memphis shade windscreen .  I changed the pitch of the screen between tires.  The avons just seem more sensitive to it.

 That's a stupid fast speed for the road, thank goodness I only did it on a closed course .

[BigAl]

As usual the Harley Death wobble gets a lot of attention on a board like this, taughting superior equipment with all things Japanese.

My Concours would death wobble at any speed unless you kept at least one hand firmly planted on the bars.

One reason I got rid of it.

Previous model GoldWings were just as bad.

I have a 2007 Electraglide and never had a wobble problem in 30,000 miles.

I suspect and some of you do, poor tire and pressure maintenance was the problem in both of the cases stated.

DOn't believe Harley Wobble,, it is a bunch of Hype.

All bikes can do it.

Simple things like unequal fork oil levels in each fork caused by poor maintenance or a fork oil leak, really the same thing.

Uneven set heights in the triple trees of the fork tubes will do it as well.

Mostly man made casuses are to blame and not the rider as the article says.


Ask any road racer and they will tell you that this is the most common cause of head shake or wobble.

[Michael K (Az.)]

Al's got it right!

[Smokinjoe-VRCCDS#0005]

I had a Yamaha XS 1100 when I was young man ....That bike would just come unglued between 100 and 110 then it would smooth out and do it again around 130.Never was a huge problem cause I knew it was going to happen plus I was young and bullet proof 

[alph]

my I/S will wobble when i'm approching a red light.  only when i'm coasting.  if you hold onto the handle bars lightly that is.  if i've got both hands on, with a good grip, no problem.

if i'm on the highway with the cruise control set, and i let go of the bars for about two seconds, it'll wobble, reguardless of speed, could be 75, or 55, it'll wobble.

[bigdog99]

i would have the tank slap wobble when i had the E-3's on the bike. one of the reasons i put CT on it.

[BigAl]

Big Dogg after E-3's get to cupping, I have even considered flaming death approach.

[FryeVRCCDS0067]

As others have said, a lot of bikes can do that. My Valk would start it at 105 or so when I had the GY TT on it, but only when riding single. With the wife and a weeks worth of luggage was she was dead stable at 125. Haven't had a chance to check it out with the new general altimax.

My V65 would go into a high speed (three digit) wobble occasionally too. It may have more to do with the large windshields I favor than anything else.

A 550K I had years ago would do it anytime I took my hands off the bars after I installed stiffer fork springs.

As Al said, a lot of factors involved. Sport bikes are probably more prone to it than cruisers due to the frame/fork geometry required for the ultra quick steering they usually have.

[alph]

alright, so, what's the best way to get out of that situation??  other than never buy a harley.....  just joking.....

i'd say that if you're going around a turn, you're not going to want to use your rear brake, that'll make the rear slide out if it locks up, and if you use the front, i'd think that would make it worse.  so, what do you do??

[Stitch_in_La]

Alph, your wobble sounds like one I had, check your front tire.  It can get worn bad on one side and you put that with certain road surfaces and it would do it.  As far as I've seen, heard, experienced the only way out of the wobble is to change speed.  Sometimes going faster, like Joe said will stop it.  Try getting the wobble in a K-5 blazer pulling a 25' travel trailer with the wife and kids with you.  High pucker factor there.

Stitch

[Westernbiker]

As usual the Harley Death wobble gets a lot of attention on a board like this, taughting superior equipment with all things Japanese.

My Concours would death wobble at any speed unless you kept at least one hand firmly planted on the bars.

One reason I got rid of it.

Previous model GoldWings were just as bad.

I have a 2007 Electraglide and never had a wobble problem in 30,000 miles.

I suspect and some of you do, poor tire and pressure maintenance was the problem in both of the cases stated.

DOn't believe Harley Wobble,, it is a bunch of Hype.

All bikes can do it.

Simple things like unequal fork oil levels in each fork caused by poor maintenance or a fork oil leak, really the same thing.

Uneven set heights in the triple trees of the fork tubes will do it as well.

Mostly man made casuses are to blame and not the rider as the article says.


Ask any road racer and they will tell you that this is the most common cause of head shake or wobble.

If you read the posts on this thread you will find no one 'TAUNTING' the Harley for it's wobble! Actually they are giving stories of their Valk wobble mostly and how different maintenance issues may cause this. Get off the Harley beating path will ya.

[f-Stop]

This report might help explain what Beau57 saw the other day...
http://www.kpho.com/local-video/index.html?grabnetworks_video_id=4697488

Here's Beau57's post in case you missed it...
http://www.valkyrieforum.com/bbs/index.php/topic,28361.0.html

WOW!

[DIGGER]

Folks, this not a bashing video of Harley as other manufacturer's over the years have had the same problem.   I am only posting this video as information about safety.  If you own a Harley bear this video in mind.

http://www.kpho.com/local-video/index.html?grabnetworks_video_id=4697488

[X Ring]

 

Marty

[DIGGER]

Folks, this not a bashing video of Harley as other manufacturer's over the years have had the same problem.   I am only posting this video as information about safety.  If you own a Harley bear this video in mind.

http://www.kpho.com/local-video/index.html?grabnetworks_video_id=4697488

sorry....didn't know Westernbiker had already posted on this subject.

[alph]

Alph, your wobble sounds like one I had, check your front tire.  It can get worn bad on one side and you put that with certain road surfaces and it would do it.  As far as I've seen, heard, experienced the only way out of the wobble is to change speed.  Sometimes going faster, like Joe said will stop it.  Try getting the wobble in a K-5 blazer pulling a 25' travel trailer with the wife and kids with you.  High pucker factor there.

Stitch

i take what i wrote back....  yesturday on my way to work, i set the cruise and rode hands free for about a mile, no wobble at all, so it must only be when i'm aproachinig a red light and i don't have my hands on the bars.   ???

[Ghost-USMVMC]

my I/S will wobble when i'm approching a red light.  only when i'm coasting.  if you hold onto the handle bars lightly that is.  if i've got both hands on, with a good grip, no problem.

if i'm on the highway with the cruise control set, and i let go of the bars for about two seconds, it'll wobble, reguardless of speed, could be 75, or 55, it'll wobble.

My #3 bike, the 2003 1500 Intruder will do it if the front tire pressure gets about 5PSI too low, especially when decelerating.  My Rune has never done it, and the Interstate will do it on those blustery days at higher speeds, but only if I relax the grip on the handlebars to the bare minimum- so I think that's an aerodynamic thing. 

[Smokinjoe-VRCCDS#0005]

http://www.kpho.com/local-video/index.html?grabnetworks_video_id=4697488

[Tropic traveler]

UH-OH.
Once TV gets a hold of a "story", right or wrong it takes on a life of it's own. 

[Garland]

A 25mph "Death Wobble"?

[ArmyValker]

"... acknowledge that their bikes are susceptible to a weave or wobble, depending on the bikes speed, but they claim this does not cause accidents.... "

That is a pretty dangerous statement if that's straight from Harley. Basically, they admit that the wobble exists, but dispute it's causing accidents... which is relatively easy to disprove. Admittedly I've had this happen on an old Goldwing, but I was riding far outside the realm of what could be considered " normal " riding, and I was able to stop it pretty quick.

As many of these bikes that are on the road, wouldn't you think there'd be far more accidents though? Perhaps this is just a function of the vast number of bikes being ridden? Imagine if there where a like number of Valk's out there...

[MacDragon]

Pretty scary stuff

[Chrisj CMA]

I read an article in a motorcycle mag, that one reason some Harleys become uncontrollable in curves is that the highly rubberized mounting system (on some models) for the engine and tranny actually allow the drive train to try to keep going straight as the rest of the bike tries to turn.  Thats what the bike in the video looked like to me that it was doing.  I doubt that could happen at 25 miles per hour though.  

This might be an explaination for why some Harley riders go 10-15 mph on the dragon

[Psychotic Bovine]

How long did it take before they acknowledged a problem with the twin cam?

[Bobbo]

How long did it take before they acknowledged a problem with the twin cam?

Probably about the same time Honda took to acknowledge the weld problems on the Goldwing...