Washboard?

[motowriter]

Originally Posted by motorrad

The road surface is dirt, wash board in places, but all in all not to bad as you continue to climb up in elevation.

Do tell... I didn't know how to describe that condition on the gravel road I explored in Death Valley, but washboard is a perfect term. So, does this condition just mar gravel, or does it apply to packed dirt too? Anyone know what brings it about? And how does one ride this without shaking off a limb?? Any advice would be greatly appreciated!

G

[ekaphoto]

I'm not sure of how it comes about, but it is on lots of roads. The best way is to stand on your footpegs, put your weight to the rear and go on over. What you are trying to do is lighten the front end, but keep it on the ground. Your arms and legs will absorb a lot of the impact the bike does not.

[motorrad]

I was pretty sure this phenomena was formed due to rain runoff across the road. Thought natural channel patterns would form during a heavy rain, and subsequent rain would deepen the channels through erosion.

Well, I could not resist, so I typed "what causes washboard on dirt roads" into Google and this came back.

http://www.straightdope.com/mailbag/mwashboard.html

If you believe everything that's posted on the web, the washboarding is caused by a vehicles suspension through harmonic oscillation effect. Once it sets up, other cars reinforce the pattern. What I don't get with this theory is why the washboard does not only form along the car/motorcycle tire paths.

Interesting theory though.

[motowriter]

Thanks for that, Tom! Oh, I believe the Straight Dope stuff... been reading their research in weekly column format for years and years (well, used to...). The guy who originated the Straight Dope series, if it's really even one guy, goes by "Cecil" and answers all manner of goofy inquiries with a stabbing wit. He takes on all comers and seems to always come up with a plausible or genuine answer. Even when subject-matter experts send him mail with a correction, the nits are really minor and insubstantial.

Anyway, the explanation makes sense. Erosion would not produce a regular pattern that perpindicularly tracks the road over long distances, through all manner of turns. It's striking that the bumps reach from shoulder to shoulder, too, as consistent traffic has to be covering all the lateral surface -- to avoid existing washboarding in the center -- to exapnd the effect across the entire width. We have the advantage of being able to navigate along a line that is 4-inches wide, but try I as I could, I wasn't able to find a line unaffected by the washboarding on the road I referred to in my original post.

I guess you win some you lose some on the side roads. What struck me was how inconsequential the effect seemed when riding it faster and downhill. Tires seemed to be gliding over them at a higher speed.

[Fastfar]

On roads that readily form washboard, vehicles aren't limited to main wheel-tracks, they end all over the width of the roadbed (from trying to avoid the washboard probably)so the darn stuff spreads like wildfire.

Agree with the on-the-pegs method.

[motowriter]

Originally Posted by Fast_Far Safely

Agree with the on-the-pegs method.

Oh yeah, up on the pegs for the gnarly stuff. Good to know, too, about keeping the weight to the rear, giving the front end a lighter travel over the lumps.

[pashnit]

My one picture of washboard...



http://www.pashnit.com/roads/cal/IdaClaytonRd.htm

[Fastfar]

Uhhggg! Not a thing one likes to see on a thightly sprung sporty, but sometimes necessary to get where we're going. (visual image of traversing 9 miles of gravel, mostly standing on the pegs letting the front just float along whilst piloting my heavily loaded V65 Magna... there was this one little stretch of downhill about three miles long, followed by the sign that kindly alerted me to 9 more miles of gravel road. )

[HIGHLANDER]

The strange thing is that washboard always come back! I used to live in a community that was 6 miles up a dirt road and every year we'd rent a grader to smooth out the road. We dump gravel , roll it, grade it , water it and in three months it would be back again,,,, then I moved to pavement and bought a steet bike again!