Tank Slap

[azrenegade]

Was watching the tube last night and they had a teaser for tonights news, Monday, for a story entitled "death wobble" what Harley Davidson is not telling you about their bikes.  They continued the tease with brief interviews with two riders that said their bikes simple went out of control and they were badly injured.

I live in Phoenix, it was either on channel 5 or 15 and will air tonight at 10 PM. I'm 99% sure it was channel 15.  I have heard stories about tank slap, death wobble, etc but have never spoke to anyone 1st hand that has had it happen to them and I've been on HOG's for 15 years, never felt it either. 

Will watch tonight and see what they have to say.

[mrmike]

I had a pretty bad wobble come on suddenly on my 03 RK, just got off a secondary highway and had just been doing a tad over 85.
Got it into a strip mall parking lot and what do you know? Flat rear tire.

You'd a thunk H-D woud have warned me that their tires might go flat and "affect" my bikes stability.

But WTFDIK?

Mike

[crash1292]

got into a nice "Potty mouth" your pants wobble on my 07 ultra after passing my buddy at over 100 and getting on the brakes hard....and this was with the missing link installed

[PoorUB]

My '05 Ultra would go into a nice interesting weave at 120 MPH or so. First time it happened I had to stop and clean out my underwear. Second time I never got off the throttle and it was a nice predictable weave, or wobble. It did not do it all the time, and I never did figure out what caused it. One trip out and it did it, next trip out, it did not.

My 2010 Ultra tossed me into the ditch at 70 when I ran off the tar and onto the shoulder and it went into a full fledged tank slapper. I blame the operator and the transition from black top to gravel for that one.

[Ultrashovel]

Wobbles are quite rare. To avoid such problems, keep your tires properly inflated and replace when necessary. Also, ride at legal speeds and watch where you are going and you probably will not have a so-called "dreaded speed wobble".

The one and only time I ever had such an issue was when I got a very sudden flat tire on a 1950 FL Panhead at road speed. It was scary but I made it to the side of the road. JMO.

[Hydroman]

my 02 Ultra would go into a wobble after hitting small bumps like going over a manhole cover for example. After fixing everything else I could think of I took the front end off and found my top neck bearing was shot. Dry as a bone by the way and I do pump grease up there once in a while. It was not the HD recommended type of grease however, but it is now...

[Nooter99]

Hmmmm...Curious...A couple of Weeks a go they kept running teasers for a local news station here in Detroit that went something like this

"What would you do if you were following a motorcycle and it suddenly, without warning, jumped into neutral!!!" WATCH THE LATE NIGHT NEWS TOMORROW NIGHT AND WE'LL TELL YOU ABOUT THIS POTENTILLY DANGEROUS ROAD HAZARD, AND TELL YOU ABOUT THE MOTRCYCLE COMPANY WHO SAYS THERE IS NOT A PROBLEM WITH THEIR BIKES!!

The video that played in the background showed the shadowy shape of a motorcycle acting erratically, but edited it in such a way that it was difficult to tell what kind of bike it was. However, to my untrained eye, it looked like it could've been a VRod!!

I never did see the actual news report. Are there any known problems like this on the VRod? as usual, with their over the top, over-dramatic delivery, they made it sound like an issue that COULD KILL MILLIONS!!

[Dennis The Menace]

A common theme in a lot of wobble reports is exceeding the speed limit.  I'm not bashing those who exceed the limit, as I am guilty as well.  But, MoCo will never lose a lawsuit on this if they find you were exceeding the speed limit.  That doesnt mean that past bikes didnt have flaws that contributed to the wobble, but that wont matter to defense lawyers.

There are enough reports of wobble to seriously wonder about design flaws.  But, then, wobbles can come from a number of different factors, including road conditions.  Too many variables to pin it down to a MoCo only problem, IMO.

[mokeypoole]

If you don't keep your steering head bearings adjusted correctly on the softail models, you will get a wobble about 35 to 25 mph when slowing down.  Its a sure sign that the bearings need adjusting.  Could be considered a death wobble

[Ultrashovel]

Goldwings, mostly the 1500's, had well-known difficulties with low speed wobbles. It usually could be traced to bad fork head bearings.

[Older-twin]

What it boils down to is making sure that you are doing the proper maintenance on your bike.  Experience has taught me that the wobble is contributed to bad or not properly adjusted neck bearings and less so to improper tire pressures and irregular wear. 

Here's some food for thought:  The older bikes always get a bad rap from people about leaking oil and marking their spot and that nuts and bolts are coming loose all the time.  What the real problem with most of those bikes is they didn't get the proper routine maintenance and that is why they leaked or lost nuts and bolts.  And so with this (not so) "new" phenomena, coming soon out of an ignorant mouth near you:  Those new Harley's have this "death wobble" and will throw you off if you don't know how to ride them..."   

[Admiral Akbar]

WATCH THE LATE NIGHT NEWS TOMORROW NIGHT AND WE'LL TELL YOU ABOUT THIS POTENTILLY DANGEROUS ROAD HAZARD, AND TELL YOU ABOUT THE MOTRCYCLE COMPANY WHO SAYS THERE IS NOT A PROBLEM WITH THEIR BIKES!!

It's the loose nut behind the handle bars!!   

Max

[apes]

Goldwings, mostly the 1500's, had well-known difficulties with low speed wobbles. It usually could be traced to bad fork head bearings.

YEIKS I have one of those, thank goodness I have a sidecar on it

[Ultrashovel]

Goldwings, mostly the 1500's, had well-known difficulties with low speed wobbles. It usually could be traced to bad fork head bearings.

YEIKS I have one of those, thank goodness I have a sidecar on it

My former 1994 SE G.W. had a tendency to cup the front tire which caused some low speed wobble as well. They are a great bike, though.   

[Nooter99]

WATCH THE LATE NIGHT NEWS TOMORROW NIGHT AND WE'LL TELL YOU ABOUT THIS POTENTILLY DANGEROUS ROAD HAZARD, AND TELL YOU ABOUT THE MOTRCYCLE COMPANY WHO SAYS THERE IS NOT A PROBLEM WITH THEIR BIKES!!

It's the loose nut behind the handle bars!!   

Max

Amen to that, brother!!

[azrenegade]

Well, watched the special last night, it was on channel 5 which is CBS here in Phoenix.  They spoke with two local riders that claimed at speeds of less than 60 miles an hour, while in turns, upon exit the bike wobbled and eventually threw them and they were seriously injured.  What I found interesting is that they had video from the California Highway Patrol that showed them inducing wobble on new HD's they were testing before deciding to choose BMW's for their CHP Motorcycle Cops.

They also reported that a "very large majority" of these issues are only found on Road Kings, Street Glides..ie..touring bikes.

Maybe something to do with the rubber mounted engine?

I am certainly not saying that low tire pressure, instant flats, improper braking, etc, etc isn't the cause but I found t interesting that the CHP could get these bikes to wobble almost evertime on high speed right hand sweepers.

Anyway, I've been thinking about the Baker +1 oil pan and stabilizer link so maybe now I'll pull the trigger and justify to the wife as a safety upgrade, Lol......

[harleyjt]

Here's a link to the story I ran into.

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

jt

[Ultrashovel]

Well, watched the special last night, it was on channel 5 which is CBS here in Phoenix.  They spoke with two local riders that claimed at speeds of less than 60 miles an hour, while in turns, upon exit the bike wobbled and eventually threw them and they were seriously injured.  What I found interesting is that they had video from the California Highway Patrol that showed them inducing wobble on new HD's they were testing before deciding to choose BMW's for their CHP Motorcycle Cops.

They also reported that a "very large majority" of these issues are only found on Road Kings, Street Glides..ie..touring bikes.

Maybe something to do with the rubber mounted engine?

I am certainly not saying that low tire pressure, instant flats, improper braking, etc, etc isn't the cause but I found t interesting that the CHP could get these bikes to wobble almost evertime on high speed right hand sweepers.

Anyway, I've been thinking about the Baker +1 oil pan and stabilizer link so maybe now I'll pull the trigger and justify to the wife as a safety upgrade, Lol......

There's more to the CHP turning down Harley-Davidsons than the alleged wobble. The last time they went big for Harleys was in the late 1980's with Evos. Their entire motorcycle fleet was FXRP's. They had to replace nearly all of the crankcases on them with about a month downtime on each one. They were all warranteed of course, but it left them wondering.

As to the alleged wobble, it's rare. 99% of the riders will never experience it. Even if some do, they will want to blame the bike. It's just human nature.

I've owned five new Harleys since 1990 and never had the problem. I guess I should be worried.......but I'm not.

[harleyjt]

As to the alleged wobble, it's rare. 99% of the riders will never experience it. Even if some do, they will want to blame the bike. It's just human nature.

I've owned five new Harleys since 1990 and never had the problem. I guess I should be worried.......but I'm not.



I've had 7 new Harleys since 98.  Never had the problem.  Too many variables involved to make a blanket statement that its a problem with Harleys.   Steering head bearings, tire condition, tire pressure, suspension pressures, motor mount condition, wheel bearings, etc, etc all figure in.  The right stack up of tolerances may cause problems.
jt

[texaskatfish]

My 'Gracie' is  2001 FLHR...................only 2 PUCKERED 'wobble moments' in over 10 yrs and 123,000 + miles:

once a repetitive wobble at 35 - 45 mph in 3rd gear (and it would definitely become a tank slapper if you let go!) R&R'd the top stabilizer link - fixed and not a problem since (typing this makes me want to go out to garage and check that link - I believe I will!)

High speed RH sweeper on northbound I-25 while pulling my trailer and got OFF the gas a bit too abruptly...........WHOA - I was using my entire lane during that one! The cure? get back ON the GAS!

[harleyjt]

.....while pulling my trailer and got OFF the gas a bit too abruptly...........


I think we found the root cause for this one, and it ain't Harleys fault.  The trailer quit being pulled and began pushing you at that point!  I'll bet it did get the wiggle wobbles.   
jt

[truck]

  with harleyjt. I've experienced it too.

[texaskatfish]

HarleyJT & Truck perzactly my intended point to be sure..............the stabilizer link wore our in normal use at approx 45000 miles (the replacement remains  solid with approx 80K on it)

That deal with the trailer is indelibly tattooed in my brain you can BET!
**gentle touch on all controls!!**

[Old Crow]

I did that taking a downhill turn too fast with a trailer on I430 in Little Rock.  To make matters worse the lanes have rain groove deep enough to loose a Honda 90 in.  I was already going too fast to power out of it, so I just made no sudden moves and hung on for the ride.  Slowed down a bit after that, too.  That was the last time I pulled the trailer with that bike until I changed out the cleveblocks, mounts and links.

[CTCVOrider]

There's a long thread about this on hdforums.com.  Many comments like 'never happened to me' or 'caused by improper maintenance, tire wear, etc.'.  The fact is that almost any motorcycle can become unstable given the right set of circumstances: speed, frame flex, swingarm flex, fork flex, suspension, braking, accelerating, surface illregularities etc.  There are also several types of 'wobble'.  The typical bagger 'wallow' often called rear steering, that shows up in higher speed sweepers or the typical 'deaccel' wobble often seen on Road Glides and soft tails.  Most of these are controlable.  The only one I'd consider to be anything close to a 'death wobble' is the high speed tank slapper - which if you've ever experienced I'd feel safe to claim you'd agree it was a major pucker moment! 

Some of these can be traced to specific maintenance items; others you may never know the cause because it only happens once and you can't repeat it.  To deny that it exists is foolish.  It is definitely NOT a Harley only problem -- almost every brand/model has experienced it somewhere, sometime.