There used to be a wonderful magazine named Invention and Technology. Back in their spring of 2001 issue (available online here) they did a very nice article on the uphill battle for bringing radials into the US. It was a battle, because when you put a radial on a car tuned for bias ply tires, it drove and rode terribly. The auto engineers, understandably, didn't see a reason to switch.
It turns out, the inherit flaws in the bias ply tire meant that engineers had been aligning their cars, as you said, with excessive toe-in to counter the imprecise handling of the bias ply tire. For a radial, however, that toe-in actually produced a large on center dead zone in the steering, and therefore a lot of wandering at speed. Take out the toe-in, things improved dramatically. That's why many cars had "Radial Tuned Suspension" back in the early 70s. It wasn't just marketing mist.
It also mentioned changes in suspension and driveshaft bushings to reduce the higher noise and vibration levels that came with radials, which we can't really take advantage of. But at least we can align our cars more appropriately for radials.
It's a fascinating article, worth your time if you love to learn the history of technology's adoption. I&T was a fantastic magazine and I still miss it after 7 years out of print. It looks like the entire publication run is available online now, if you need a way to kill some time.
It turns out, the inherit flaws in the bias ply tire meant that engineers had been aligning their cars, as you said, with excessive toe-in to counter the imprecise handling of the bias ply tire. For a radial, however, that toe-in actually produced a large on center dead zone in the steering, and therefore a lot of wandering at speed. Take out the toe-in, things improved dramatically. That's why many cars had "Radial Tuned Suspension" back in the early 70s. It wasn't just marketing mist.
It also mentioned changes in suspension and driveshaft bushings to reduce the higher noise and vibration levels that came with radials, which we can't really take advantage of. But at least we can align our cars more appropriately for radials.
It's a fascinating article, worth your time if you love to learn the history of technology's adoption. I&T was a fantastic magazine and I still miss it after 7 years out of print. It looks like the entire publication run is available online now, if you need a way to kill some time.
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