What explanation is offered for sickness in Ajax?

What mechanism might explain the reported sickness experienced by people travelling in Ajax?

The answer tentatively suggests chassis alignment and dimensional problems causing unusual motion; it does not establish a verified diagnosis.

A follow-up asks what mechanism could explain reports of sickness while travelling in Ajax. The response suggests chassis alignment and unequal dimensions as possible causes of unusual motion. It compares the effect with riding in a car whose chassis is not built to the correct shape. This is a proposed explanation in the discussion, with no measurements or engineering investigation supplied to establish the cause.