[EricH]

I think that the size change was FIRST's way of giving notice: Anything can and will change at any time.

Before this size change, the size has stayed the same* since 2005. Before that, the size stayed the same for several years; I don't remember when it became 30"x36"x60" so I can't say anything about how long. Teams have locked into--and to some extent assumed--a constant size. A number of offseason drives have been prototyped, at the 28"x38" size. Maybe one or two offseason drives snuck into the competition. (Note: I do not include the extension limits as part of the size here; those changed every year.)

The size change changes all that. It forces teams to adapt--or engineer--their designs. It also opens the design up a bit, making the competition harder. And, it's really, really easy to tweak in future. Just change one number, and watch the wheels in 20,000 heads start turning.

Incidentally, when I competed in SAE Aero Design's Regular Class, there was a similar limit to aircraft size: length+width+height<=X, and X could change year to year. We tended to build to a long wingspan. Other teams built more to the long tail or tall height sides of the spectrum. In different years, with somewhat different rules, different long dimensions did better.

I think the size change will be semi-permanent. That is, the change in how dimensions are calculated is probably here to stay for several years; the actual number will probably vary year-to-year.


*Barring 2007's varying height, which did not affect the perimeter size, but was rather popular in public opinion.