Explaining washboard damage

I know that Australia has some l-o-n-g heavily wash-boarded tracks. I also know that washboard can destroy vehicles.

Yet, this piece is about a road in Death Valley that is driven by whoever not, including rental sedans. There are trip reports about it on both the OB and the Foz forums. It does have a reputation for punctured tires and washboard but I had not heard anything apocalyptic. Yet, this apparently happened:

https://www.edmunds.com/car-buying/...AID=10364102&mktid=cj260233&mktcat=affiliates

What do you think? I suppose they may have happened to drive it at the worst possible time, when severely washboarded and their speeds are in the dreaded mid-range for washboard. Still, destroying struts so quickly? The article does seem keen to show the capability of the independent suspension Honda.

My first thoughts - not aired down and travelling too slow. Should've been doing 40-50 MPH; you need to ride on the top of the ridges not bumping up and down in the valleys. My Triton is happy around 80 KPH / 50 MPH on most corrugations.

I'd follow what Kevin says but the interesting part is that all three pickups did the same track and the Ridgeline had the least damage to the suspension so its also probably due to the quality of the shocks and the different live axle vs independant suspension design.

On my '07 trip to Morocco, after few hundred kilometers on corrugated tracks I blew both rear top mount bushings even though I always travel very light (the SLS shocks were still in very good shape and lasted 4 more years !).

I believe that the rear suspension parts are more prone to breakage due to the bigger oscillations of the vehicule at the rear.

What does a blown rear top mount bushing feel like?

Other than choosing the worst speeds and pressures, what can one do to test/damage the vehicle on a washboard?

MiddleAgeSubie said:

What does a blown rear top mount bushing feel like?

Click to expand...

It rattles and makes some big "klonk, klonk, klonk" because there is no more rubber (in fact, the rubber is like dust !) between the metal parts of the bushing, other than that, you can still drive the car carefully and go home. I did an interim fix with some pieces of truck tires found on the track because I had 1'500km back to Switzerland.

MAS, we call them corrugations here.

IME, every piece of corrugated road has a different wavelength or natural frequency. The trick is to find the speed at which the car's natural resonances and the frequency of the corrugations are not in harmony with each other! There are usually multiple speeds, starting at a low speed and then at points multiplied by two. eg 8 mph, 16, 32, 64. The starting point will be different for each set of corrugations.

The natural frequency of any particular set of corrugations will be determined by many factors, including soil type, resonant frequency of the vehicles that most commonly use the road, what speed they travel at, etc, etc.

So, is it possible that some wavelengths are more likely to cause damage than others?

The lower the frequency of the corrugations, the greater the number of damaging harmonics, and the harder it is to avoid travelling at any speed that avoids them.

One should just travel very slowly over such stretches! These are not uncommon, but very easy to detect. If you can't find a speed where the car rides smoothly, slow down until it doesn't shake your teeth out. Chances are that the next section will be quite different.

Applying these strategies flexibly will minimise the chances of damaging the car.

I hate corrugations with a passion.
I bent a rear strut on the (almost) trusty MY03 on the Finke track in 2012. Strange tyre wear after that until I realised what was wrong.
It does not matter what speed I travel at corrugations are still S..t !!!!!!!
Traveling to Cape York in 2007 the vibrations were so bad that the rear gate catch steel supporting surround fatigued and broke requiring a weld job.

Yeah, Ate. No such thing as good corrugations ...