There are two things you don’t want to hear in the same sentence: “Harley” and “Death Wobble”.
I came across this story from KPHO Phoenix which describes the phenomenon:
A camera mounted on a Georgia state trooper’s police-issued Harley shows Officer Richard Barber traveling 90 mph along an interstate. His 2007 Harley Electra Glide begins to shimmy and wobble. Eventually, Barber is able to stop the bike safely.
But a Raleigh, N.C., police officer was not so lucky. In 2002, 30-year-old Charles Paul was thrown from his Harley Electra Glide after it began to wobble. He died, and his family later settled a wrongful death suit with Harley-Davidson in 2008.
KPHO’s video on the topic can be found here.
Uh, really ? It gave me some pause since we ride a 2005 Ultra Classic, but not being versed in the ins and outs of the whole thing, I asked my resident expert Chainsaw.
As usual, I got a thorough answer, though perhaps more than I bargained for.
Here is his reply, written as only Chainsaw can write it:
You don’t ask the easy questions, do you?
There are a lot of things at work here, and I’m gonna tell ya more than ya expected to know.
In 1980 there were only 2 bikes that had rubber mounted motors. The earlier models were bolted through a motor mount boss welded onto the frame, through a corresponding cast aluminum bolt hole in the bottom end or engine cases that housed the flywheels, crankshaft, piston rods and oil pump.
The one and only touring bike at the time, the FLT, was rubber mounted, and the one and only rubber mounted FX, was the FXB, or the “Sturgis” model, and it was the 1st belt drive bike.
By 1985 all models, except maybe Sportsters, were rubber mounted motors, and the Shovelhead engine had been replaced by the new “Evo” or 80 inch (1340cc) Evolution engine.
That’s when the “overnight sensations” and yuppies began to appear on the roads because the Evo motor was proported to be as tight as a thermos bottle, and wouldn’t leak oil. That was appealing to the morons that just wanted to ride and show off that they owned a Harley.
Well, I’ve dropped a thermos before.
Evos were a tight motor, and still are today. Some folks still swear by them, but they don’t last long on an 800+lb touring bike, and these are the bikes that I am going to refer to as they have in the story.
Since the 90’s, the motors and transmissions have been “rubber mounted” with massively dense rubber bushings to the frame and swingarm in the FLH family of bikes: Road King, Street Glide, Electra Glide Standard, Electra Glide Classic, Electra Glide Ultra Classic, Road Glide, or any bastardization of those models, either for Police use, a Custom Vehicle Operations bike which usually have a 103″ – 110″ motor on the frame, slinging massive amounts of torque to the motor mounts and swingarm mounts.
The motor bushings do wear out after a bunch of miles and normal service.
Sometimes the bikes come from the factory poorly assembled and they wobble around 80 mph, but you turn right around and go back to the dealer and tell them to shove the piece of shit up their ass, and tell them to get the paperwork out and rewrite the deal on another bike.
Then there’s the final key piece to this puzzle that Harley-Davidson won’t admit to being a factor in the “Wobble Syndrome.”
Anyone that has gotten down on the ground and looked at how the motor and transmission are mounted on the bike, or is a mechanic, will see that the transmission is not solid mounted to the frame per se, it is mounted through those dense bushings that do double duty as engine mounts and swingarm mounts.
That is the weak link in the whole scenario.
A little bit of physics knowledge will tell you that the swingarm is for the rear suspension or shocks, for up and down vertical travel, not side to side horizontal travel, yet the motor and transmission are hard mounted together, and the rear of the transmission mounts to the swingarm pivot point.
That’s why when I kept saying a while back that the front and rear wheel on our ’05 Ultra didn’t seem to track along the same line, it’s because the back wheel had thrown a wheel weight, and when I got a new tire put on and they balanced it, that shit was gone. Just that little bit of that weight being thrown on changed the physics and performance of the pivot point rubber mount on the swingarm.
We’ve not had any issues with the “wobble syndrome” because of the way that I ride – I feel the bike, I listen to the bike, I become part of the bike, and if something is not quite right, I know it immediately, even when the bike is loaded down, pulling a fully loaded trailer. I can feel the horizontal forces, but I ride accordingly.
There is a part on the market that solves the horizontal effects on the swingarm pivot point, and that is all that is required to give that particular set of bushings a gazillion miles of dependability and service. You’ll notice on their website, a picture of someone laying hard into a corner. That’s what this is all about, the sideways, lateral forces that put the load on the swingarm bushings. At their products link, the year models of applications correspond to the beefiness of the product as the year model of bikes go up in motor size and horsepower – factory horsepower that is, not hot rodding a motor to unreasonable cubic inches like Checkered Bob’s 124″ desires.
The thing that people, and the goddamned media don’t realize is that the laced wheel or spokes were not designed to carry the weights that touring bikes carry now -You have the weight of the bike itself (approximately 800 lbs), the rider and passenger weights which can vary anywhere from 350lbs to 500lbs…. add that together with the kinetic force of real time riding, and the swingarm pivot point bushings are performing under the pressure of over a ton. Factor in the dainty (but cooool looking – not in my opinion) laced spoke wheels and you have a 2nd issue that can spell disaster.
That’s why Harley-Davidson and the report made mention of, “added on parts.” You’ll also notice that neither one mentioned what add on parts they were referring to.
It’s the laced spoke wheels, or anything that adds weight to them is when the dangerous natural lateral forces come into play.
The reason that “other” manufacturers’ bikes don’t do it is because of initial standing weights and the motor mounting and drive trains are completely different.
You can’t compare apples to oranges.
The Police bikes that they referred to that went out of control needed a steering damper, not so much the tru-track motor/tranny/swingarm brace, as the damper is used for speed and stability. The tru-track may have helped, but what would’ve helped out more would have been a tighter maintenance schedule as those bikes get the bejesus beat out of them and if your machine’s key components are held together with rubber bushings, they will wear faster.
This article got me pissed off. It shows how naive the general riding public and media are.
Hell, I’m done with this subject, I gotta go take a dump.