Another article on something the dealers call "NORMAL"

The Dreaded Speed Wobble

This is a panic-inducing temporary loss of control of the front forks. However, do not automatically assume that the forks cause it. The rear swingarm assembly and numerous other conditions may be the culprit. This is one reason that the condition can be difficult to diagnose and therefore repair. The mechanic may be attempting to correct a perfectly functioning part, assembly or adjustment.

The Lord’s Prayer & the Harley Elders

You know you are in a speed wobble when you are trying to remember the Lord’s Prayer. It may only last a few seconds, but it strikes without warning……or does it? As we progress, you will understand that mishandling of any type is predictable. It is invariably caused by mechanical problems, maladjustment of component parts or design defects. External conditions such as road surface or wind shear may exacerbate the situation. The Harley Elders will sagely inform the newcomers of their experiences in the old days. I don’t know why, but the old days stories are always worse than the present day ones.

“Tank Slappers”

The handlebars would develop a mind of their own, start to fibrillate for no apparent reason, then shake more violently, until the bars would be torn from the hapless riders hands and slap the gas tanks. Me? I’m an old guy. But I have never seen or experienced this but that doesn’t mean it hasn’t happened. If you ask my opinion it has….in the old days….but not in modern times. The fact of the matter is that in the old days roads were not in as good a condition as they are today. Motorcycles were not built as precisely either. The maintenance of bikes today is superb relative to what it was like when I started riding. This is why I believe the tank slapper stories did occur. I am very happy that I can’t report to you, the reader, exactly what it was like. A modern motorcycle in good repair would never get to that frightening stage. Accelerating will get rid of the dreaded wobble. This takes courage. I, like the majority of riders would slow down which in my experience also cures the problem allowing the bike to stabilize. I have owned Harleys of every shape and form for 30 years and one Indian 45 that couldn’t get going fast enough to have a wobble.

My Experience

However, I had never experienced a speed wobble until I was riding about 15 years ago along a highway at maximum speed. The FLHT, began to do the shimmy while I was passing a tractor-trailer as fast as the bike would go. There’s no better way to convince a rider to slow down. I believe that the FLHT series of Harleys are not designed for sustained speed at over 90 mph. The tires are rated for it, the engine doesn’t mind and neither does the rest of the power train. But the FLHT frame-faring-beer box design is not!

Rake, Stretch and Reversed Crowns

The frame neck angle has a big influence on handling characteristics at different speeds and riding conditions. Increasing the neck angle on a frame will cause a bike riding in a straight line on good pavement to be more stable. Rake is a measurement of the steering axis from vertical, given in degrees. In plain language, this is the fork angle measured from an imaginary 90-degree line.

Less rake will make the front end seem lighter which may not be desirable at high speed. More rake, while assisting in hi-way riding, can make a bike ill-handling at low speeds in tight turns.



Long Legs

This awkwardness is extrapolated by the heavy FLHT, which until recent years assumed that we all had very long legs. Harley Davidson’s concept of the average riders size is way off on the big baggers.In the last two years, the Factory has realized that the average riders legs are much shorter than previously thought. Harley has lowered the bike to accommodate the majority of us that had to tip-toe around while navigating the b