When I'm planning to use a multi-wheeled (more than three) model in a dio, I always explore making the suspension flexible. Sometimes the model is easier to modify than it appears at first glance and sometimes it requires a reengineering effort. The latter you decide if the effort is worth the result as the dio envisioned may be easier to adjust than the model, as may be the case above. For future reference, second cuppa. BTW, your modeling results are pretty amazing for the short time you've been at it, IMHO. PaulE