I had a good friend who was injured badly (broken collar bone, etc.) from a tank slapper on his Honda CBR sport bike a few years back. It is not only Harley's, however it is a fact that the setup of the swingarm etc on baggers have been known to cause this which is why companies like True-Track exist. This is TT's whole basis for their advertising campaign.

My friend Paul pulled a wheelie (he was extremely experienced with trick riding) and when he put the front end down went into an insane tank slapper. Another friend of mine was right behind with a video camera on his helmet. He smacked into a parked car on the side of the road as a result of the tank slapper. I will not psot a link to the video out of respect, although it has been seen on some television show on Fox a few years back.

Ride carefully as we never know what is waiting for us "at the end of the road."

My condolences for your friend. Be careful.

Drew

 

My bike picked up the wobble a couple weeks ago. In a straight line going between 65-75mph it would just start to wobble. I was set out to go camping, but had the same gear as before and didn't have a problem last year. The thing is it took the curves great. I was scraping pegs and had no wobble, but on the highway going 65+ it would be fine then out of the blue would start right up. If I stretched out and put my heels on my forwards it did it again. I move my tent from the bars (it has been mounted to the bars before with no wobble) and moved it to the tour pack and it went away for the most part. I can slightly feel it there, but I was comfortable again. I have tightened the fall away and it helped so I may need to do it a hair more. My alignment checks out fine. The only thing I can think of, if the fall away doesn't cure it, is that I went to a lower profile rear tire which lowered the rear a little. I went to a 21" front which raised the front an inch. From reading in the past if the front is higher then the back to much it can create a wobble. When I replace my front springs this winter I may lower the front an inch and see if that helps if I haven't cured it by then. I also put Dyna Beads in my tires and went through the mountains 85-90mph with no problem, it helped even more. It's still there barely, but I think if I tighten the fall away some more I should be good. From what I've been reading there are tons of things that could affect it. I also heard a bad motor mount can cause it as well. I may change that this winter for my 10k anyways.

 

70-75 on a freeway taking a turn is not "beyond the limits" of a touring bike or any motorcycle. hell it isn't beyond the limits of my subaru.

if harleys can't turn on a freeway at 70 MPH they should all be recalled and never ridden again. it's a motorcycle and 70 MPH is "flow of traffic", my HD can ride with the flow of traffic and then some.

this was a violent head shake which could've been brought on by any number of things, which brought the rider out of his lean and he hit the barrier. terrible accident and my condolences, but head shake or death wobble happens on all bikes just google it and read the sport bike forums on it, you can't upright a bike in a turn at 70 MPH, head shake, tank slap or not, bad things will happen.

 

Yes does read bad but it was on a straight stretch of road with a slight curve.

We ride on the left here in the UK remember.

 

I could go research but would somebody mind briefly explaining "Tank slapping" and "Head shake" ? I assume "Death Wobble" is the final stage of both of the aforementioned?

True track is supposed to solve all this?

If this sounds dumb just forget it, but is this something like hitting a tuning fork to create vibration then you cross a finger over the forks to stop it?

 

a tank slap and "death wobble" are really the same thing. it's basically an oscilation of the front tire where it will almost vibrate one way, then vibrate the other way to compensate leading in a tire that basically wobbles back and forth violently. if you want to see a good recovery check out this gentleman, it shows the wobble, but the guy comes out of it, i don't want to post a vid of someone getting hurt:

http://www.youtube.com/watch?v=6Fa0GmdSN4A

that is a death wobble coming out of a turn and an insane recovery.

 

The question in the original post looks like somebody trying to set up a lawsuit against Harley Davidson (having been involved with such things a time or two, myself). Not uncommon for people to want to blame whoever has the most money in a situation such as this.

While I haven't heard of "speed wobble" being a major Harley issue, it seems to be pretty common with Jeeps and happens to everything from trucks down to skateboards.

Looks like BS from my perspective.

 

I think I saw this video. Is your friend deaf? If it's the one I saw if the car wasn't illegally parked he more then likely would have made out a lot better then he did.

I hope I never experience the death wobble.

 

Exactly! However, if it proceeds (and it's here in the US), it probably won't just be HD who they go after. It will be anyone & everyone with any kind of involvement - from HD to the maker of his helmet, most any ambulance chaser... 'er, I mean, attorney, will drag whoever they can into it.

On one hand, I can see going after a company if, in fact, the accident was a direct result of bad manufacturing or a defect that they were aware of and did nothing about, etc. But on the other hand, I think that more people need to take responsibility for their own actions and accept the consequences. I'm not saying the guy was riding beyond his ability - I'm just sayin'...

 

My '06 Road Glide would do this. Usually on the freeway, going around bends at the posted speed limit (65mph). It seemed to be worse if there was a 'hump' in the roadway at the entrance to the corner. It felt like the back wheel was oscillating underneath me. It got real scary a couple of times.

It turns out (as I understand it) that the Touring bikes have rubber-mounted engines with three mounting points, and the rear swing-arm is mounted into it, and if I loaded the rear wheel in the wrong way, it would flex and straighten-up, over and over. Changing motor mounts helped, but I could always feel the rear-wheel wanting to try to do this. There were a couple of places in my regular commute that always made the bike want to do this, and they all had a bump or a rise or fall in the roadway. I bought a stabilizer, which made it much better. But I could always feel the rear wheel wanting to get unsettled underneath me, but it always stayed controlled, and I never had the movement that made me think I was going to run out of pavement before I hit something (this nearly always happened with a concrete barrier close by.

Something similar to this happened to me on my BSA once, when it was old with hard tires and wire-spoke wheels. But my Road Glide always had tires less than a year old, did not have wire wheels, and was maintained by the book. I told my wife that if I was ever found off of my bike with no obvious reason, that she should have someone look at the HD wobble as a possible cause. When my bike wobbled, it was scary.

HD has since changed the frame, and added another motor mount.