TOLERANCE STACK Articles

This write-up covers the seat bottom only, the cushion and everything underneath it. The seatback is its own animal and we haven't gotten into it yet, partly because the bottom alone turned out to be enough to chew on for one stage of the project. That's not an arbitrary stopping point either. It's where the bottom assembly naturally ends and the seatback assembly begins, and it happens to land at a convenient place to pause anyway, which we'll get to by the end of this.

The objective was not to invent a new approach, but to confirm whether existing assumptions held true on the Sequoia and to identify any platform-specific differences that required accommodation.

This is how we design our mounts to work—with the scheel-mann seat’s mounting boss (the six round metal posts under each seat) dropping into a precision-cut hole. We supply a custom flange bolt that holds everything together from the top. In this setup, the mount carries the side-to-side forces, not the bolt. That keeps the bolt out of shear and makes the entire connection stronger and more secure.

The truth is, our bodies weren't designed for hours of sitting in one position, particularly in factory car seats that treat the human spine like a straight line rather than the elegant curve it actually is. Standard car seats, especially as they age and wear, often fail to provide the support our backs desperately need. This isn't just about comfort, it's about preventing real medical problems and managing existing ones.