Washboard Driving

[Advanturetrek]

Seeking advice on best driving techniques and gear for washboard. Just had a few bad days of it. Hoping for better.
The SMB can mechanically do washboard just fine. But, at any speed, the van interior and Aluminess racks rattle horribly. We had to go 5-10 mph to keep the rattles tolerable. Regular cars were passing us going 30-50 mph.

We've got Old Man Emu Shocks, and our gear is well tied-down.
Didn't air down because we're not sure what pressure to aim for, based on the weight of the van and the tire type. What is the best way to get that information?
How much does airing down help with washboard?
Any other driving techniques or gear to consider?

[saline]

Airing down helps tremendously!!! However, there is a fine line of running too low of an air pressure on these heavy vehicles, especially at speed.

[BajaSportsmobile]

Set your tires at 25 Psi and you will be much happier.

[Nomadcat]

There is the tried-and-true "5 or 50" rule, but 50 on washboard is a lot scarier in my van than it used to be in my Tacoma or the Wagoneer.

[EMrider]

Washboard roads are always going to be uncomfortable in an SMB.

My optimal setup for "least unpleasant" washboard driving includes:

1. Air down to 35-40psi
2. Put transfer case into low range
3. Engage 4x4

Good luck
R

[yvrr]

Our rule of thumb is 35/35. Air down to 35 psi and drive 35 mph. We have a Hella tire pressure monitoring system which is turned off when I air down (otherwise, it will continually beep) but I stop and check the tire temperatures on a regular basis.

Tire size is also a factor. If the washboard condition has been created by cars with smaller tires, larger tires let you get up "on top" of the ridges somewhat.

[geoffff]

I wouldn't go into 4x4 low -- you won't be able to drive fast enough to "float" over the bumps.

Like many people here, I air down and drive fast. Still the experience can be unpleasant to terrible depending on the intensity of washboarding. My pattern is:

Tires: 30-35 PSI
Speed: 35-50 MPH

Yes, 40 MPH will seem scary fast. But slower than that, the bumps get worse.

I also usually stay in 4x4 (high). This helps during the uphill sections.

I often spend a lot of time studying the road looking for the smoothest track. This is usually way off to the side -- but here you are in danger of hitting stray rocks or veering off the road. And, staring at the road all the time like this means you aren't enjoying the scenery.

If the road gets too horrible, I immediately drop down to 10 MPH.

-- Geoff

[macmcintire]

In addition to all of the above, I drive on the left side of the road. I don't know why that works, but it always seems to be smoother on the opposite side of the road. This of course, doesn't work on busy dirt roads.

[geoffff]

Originally Posted by macmcintire

In addition to all of the above, I drive on the left side of the road. I don't know why that works, but it always seems to be smoother on the opposite side of the road. This of course, doesn't work on busy dirt roads.

Now that you mention it, I have noticed that too. Apart from hills (where the uphill side is worse because of traction issues), I thought it was just my imagination (grass is greener etc.), but now that I think about it, the washboard bumps themselves may not be symmetrical so hitting them the opposite way could feel different. If you believe simulations like this, the bumps are in fact asymmetrical -- they ramp up, and then drop off to start ramping up to the next bump.



-- Geoff

[daveb]

I'd say my Deaver springs have made as much difference as airing down to 40PSI. Also disconnecting the front sway bar helps a bit.