In my open thread about repairing my F350 bed, Don Curley brought up the issue of how folks drive on washboarded roads:
"Going back to your comment about washboard roads, I can't help but wonder how many of these types of roads you have been on with your rig and what your general approach has been for driving on them. What I am getting at is that some folks approach washboard roads with going quite slow, while there are those that use the logic of going as fast as safely possible, where maybe they can hopefully find that sweet spot of just hitting the "peaks" of the washboard "peaks & valleys" profile. My concern here is that you can obviously get quite a hammering effect from washboard roads (depending on conditions, speed, and duration), and with a heavy camper in your bed (that you mentioned moves around quite a bit), that maybe this damage started happening from the washboard road effects ... and just continued to get worse over time. "
I know I have read posts from people who did the White Rim trail (was that you, too, Don?) who actually dropped the air in their tires to something like 25 psi and then used CO2 canisters to reinflate. I've seen other posts where people try to adjust their shocks.
I personally try to find what I guess Don is calling the "sweet spot", though I don't drive "as fast as safely possible". If I go too slow (generally less than 15 mph), it's a gut wrenching ride (and you subject yourself to it for twice as long as if you were traveling at 30 mph!). I'm afraid to go too fast, though, because all it takes is one big jolt that you did't see coming, and you can do real damage. So I'm typically about 30 mph, where at least my stomach muscles aren't totally knotted up.
I'm wondering how other folks approach this type of driving and if anyone has tips to make it more endurable both for the truck and its occupants.
The only thing that actually helped on washboard roads, was using a motor-home instead of towing a trailer. Finding the sweet spot in speed helps, but getting off the interstate with the problem, and traveling on a parallel route may be better. If you are feeling a hard bounce, it isn't doing any good for any of the components in your rig. Lowering tire pressure is only used for extremely slow speed travel, and would be suicidal in this case.
Mark
Mark & Jan "Old age & treachery win over youth & enthusiasm"
2003 Fleetwood Jamboree 29
...but seriously, we were lucky enough to have timed the grading of the the longest washboard road we've ever driven: the Chaco Canyon access road. I stayed about a half kilometer behind it as grader did about 2/3rds of the road for us
No suggestions. Just feel it out; washboards come in all shapes and sizes. One note of interest: don't drive these things too fast (fast for me is ~~20 MPH over most).
That was me (who with Steve_in_29 and Nemo667) did the White Rim Trail in March. However, as far as airing-down our tires, none of us ended up doing that for the WRT trip. While it is quite typical with smaller 4x4 vehicles to air-down the tires for better traction and comfort off-road, we were concerned about potentially losing too much side wall strength and therefore the weight carrying capacity of our tires with the load of a camper in our respective beds. So, we approached this from the angle of traction. If we found that at full inflation pressure (65 PSI for my load range E 35x12.50R17 Toyo Open Country M/T tires), that we could maintain good traction without spinning any wheels, then we would just stay at full inflation. If not, we would air down accordingly. Well, as it turns out, we had no problems with traction even when going over the rather challenging sections of the WRT on the second half of the trail, so we stayed at full inflation. Of course, we all had off-road tires, so the more aggressive lug patterns no doubt helped offset the full inflation aspect from a traction perspective.
This is not to say that in all cases you would stay at full inflation off-road, as you could run into some lower traction situations with sand, mud, and other loose surfaces where airing-down would be advisable or even required to continue on. In such cases, you just need to find the right balance between increasing traction versus maintaining enough load carrying capacity in your tires as a function of air pressure when you have your camper on board.
In terms of washboard roads, that's a tough one IMO. With my smaller 4x4's through the years (the majority of which were modified), I usually try to find that "sweet spot" by going damn fast. However, with this method, many times you are at the edges of keeping control of the vehicle. Additionally, the problem with the "sweet spot" approach is that the "wave length" of the washboarded road isn't a constant (that is, the relative distance between the peaks and valleys doesn't stay the same). Therefore, trying to maintain a given higher speed isn't always going to cut it in terms of just trying to hit the high points to smooth things out a bit. Going too slow is just as you described it. Since I am not going to drive overtly fast with a full-sized truck and camper, I find myself slowing down and trying little tricks like getting at least one side of the vehicle's tires on something smoother or at least a different "pattern" (which I typically find on the passenger side shoulder area, if it's to be had at all). I may also diagonally cross-cut in some sections of a long washboarded road.
I don't pretend to have "the answer" to driving washboarded roads, and other than mud, I hate the damn things. The whole time I am on them, I am just figuring that everything is getting beaten to death, bolts and nuts are vibrating loose, and even uglier things could be happening. As a side note, one of the worst (and extended) washboard roads we have been on several times in years past is the Saline Valley road coming down into the Death Valley area from the north. That one will jar your brains out.
Actually, I was thinking of the interstate in parts of SD and MN. We just were in WY two weeks ago and roads were fine. As far as gravel roads go, I blame the gravel roads for loss of a refrigerator, and a closet-door with mirror on a past trailer. As for gravel roads with washboard effect, traveling 10-15 mph and towing in 4-wheel drive works best. Takes forever, but you might get there in one piece.
Quote: Takes forever, but you might get there in one piece.
You bet ya!
You mustn't have drive the I80 east-bound for much of the State, then? Barely a year ago since we last drove it, and the cement "shaving" hadn't been nearly completed then. Is this a done deal now? If it's been shaved, we're changing our routing plans next trip out...
That "sweet spot" speed is where the natural resonance of your suspension matches the speed the bumps are coming at. That's why the washboards grow: every vehicle that runs at the resonance speed instead of a much lower speed will re-enforce the pattern and pound it into a taller washboard.
One thing to watch is that you may be doing the sweet spot for the front axle where you get the most feel in the cab from, but the back axle is pounding the camper.
If I had a bunch of driving on washboard to do, I would try lowering the pressure. Not down to sand driving pressure, but maybe 30 to 40 PSI. You're not going to be going fast anyway so the tire won't overheat.
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