Combo suspension
{assuming I have this correct}
Bendix had a patent on the suspension system for their combo. No other manufacturer could use that method, and thusly all other combos had to limit spin speeds due to suspension issues, until Whirlpool later came up with the very complex water-balance system. The limitation came into play only on combos, not on frontloaders that were only washers.
The Westy combo's tub/basket moved ONLY horizontally, no vertical or diagonal movement. IIRC, the tub on Westy frontloaders dropped down a bit during fill from the water's weight, and the boot deformed/wrinkled slightly. The combo did not do that. The front panel flexed very slightly with the side-to-side movement during spin. Also fun, it filled from between the inner basket and outer tub. There was no obvious stream of incoming water during fill, the water level slowly rose up through the perfs as it tumbled.