Why do they make roads that cause porpoising?
Just got back from the "big" camping trip of the year. The last 5 or so miles on the East end of Interstate 490 in New York is fairly new concrete. My truck is nothing special, a regular cab long b...
Forum Discussion
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Porpoising occurs when bumps in the road match the natural frequency of the truck suspension. Unfortunately all automotive suspensions are tuned near the same creature-comforting low frequency. Adding adjustable Rancho shocks set to high might damp it.
About 20 years ago, part of I-94 through North Dakota was poured with immediate high joints. It was fixed by grinding off the humps/joints. Carborundum stock must have climbed the day that contract was signed.
Some sort of later I-94 foul-up caused a pair steady 12" by 4" block cuts to be made every few feet to cut some sort of imbedded rod or cable, ostensibly to prevent a similar bounce. Thousands and thousands of cuts.
I blame it on progress. Whereas workers used to accurately level stuff (think still surviving Roman roads) with string and bubble-levels and understand what the heck they were doing, now it is done with "buzzword" lazers, and nobody onsite understands, or cares, what the automatic leveling machine is supposed to be doing.
I submit this is similar to cock-eyed automatic lazer tire alignment machines in vehicle service bays everywhere. I just bought a "pre-owned" truck with fairly new tires and concurrent new suspension parts. The nearly new tires... aligned-by-lazer... were obviously wearing in an over-toe-in condition requiring me to eyeball them back to straight ahead specs the old fashioned way. Not to mention, I think the new balljoints are torqued too tight.
Geez. What happened to good ol' common sense.
Wes
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Porpoising occurs when bumps in the road match the natural frequency of the truck suspension. Unfortunately all automotive suspensions are tuned near the same creature-comforting low frequency. Adding adjustable Rancho shocks set to high might damp it.
About 20 years ago, part of I-94 through North Dakota was poured with immediate high joints. It was fixed by grinding off the humps/joints. Carborundum stock must have climbed the day that contract was signed.
Some sort of later I-94 foul-up caused a pair steady 12" by 4" block cuts to be made every few feet to cut some sort of imbedded rod or cable, ostensibly to prevent a similar bounce. Thousands and thousands of cuts.
I blame it on progress. Whereas workers used to accurately level stuff (think still surviving Roman roads) with string and bubble-levels and understand what the heck they were doing, now it is done with "buzzword" lazers, and nobody onsite understands, or cares, what the automatic leveling machine is supposed to be doing.
I submit this is similar to cock-eyed automatic lazer tire alignment machines in vehicle service bays everywhere. I just bought a "pre-owned" truck with fairly new tires and concurrent new suspension parts. The nearly new tires... aligned-by-lazer... were obviously wearing in an over-toe-in condition requiring me to eyeball them back to straight ahead specs the old fashioned way. Not to mention, I think the new balljoints are torqued too tight.
Geez. What happened to good ol' common sense.
Wes
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