The road to Chaco Canyon Vs. Bilstien 5100's
And the road won.. Usually you can go over wash boarded roads fast to smooth things out but this road was so bad I was stuck doing 5 to 12 mph.
Forum Discussion
You're not taking into consideration that gravity is only 32 ft/sec^2. It takes time for a tire to fall from the peak of the ridge to the valley, especially if the wheel has a little upward momentum left over from going up the ridge. If the tire reaches the next ridge before it can fall all the way into the valley, it smooths out the washboard.
Your suspension doesn't just 'fall' by gravity though...
It's pushed by the stored energy of the compressed spring. Ever see how much energy a spring that's been compressed a few inches by a ton when it's released. Moves pretty fast!!
By your description, the tire is airborne and SLAMS into the next washboard bump; a very harsh ride indeed!!!
I race off road motorcycles and have spent a lot of time with suspension in washboard conditions. I can tune a shock so the bike rider isn't even aware that he's traveling over anything more uneven than asphalt paving while the washboard is up to 10" deep. (13" of suspension travel in the shock.) Smooth as silk. Even more; there's not only compression and rebound on damping, there's high speed and low speed damping. Wash board is low speed; where the ground transitions fairly smoothly in rolling ground. High speed damping is with an abrupt edge. Like maybe hitting a curb head-on at speed.
Then there is damping for the various area of the shock's piston stroke; initial / mid and end of the stroke. This allows a shock to have stiffer damping as the shock piston is moved through it's stroke.
Shock engineering is quite a science.
