They've been called Rokon for years. The company has been resuscitated a few times, but the design though improved is roughly the same for 30 years or so. It is hard to believe, but they weigh in about the same as a CRF250R at 200-208lbs depending on the model. There seems to be no attempt whatsoever to use lightweight materials, and they are huge, but the scales don't lie. However, it is almost an irrelevant fact because you never leave the ground on one (not enough speed or suspension). My 2nd bike was a Ranger (identical to the Trailbreaker, but forks chopped and with smaller, spoked rims instead of the hollow tanks). The only race I would enter with one would be something like "see that wooded mountain with no trails? I'll beat you to the other side of it", or perhaps...I'll beat you around this MX track on your CRF450R, each of us dragging a 500 lb log behind. You can drive over a 55 gallon drum on the Trailbreaker. My dad had several Trailbreakers over the years and restored several from the early 70s, including mine, during the late 80s. They are one of the few true "all season" bikes that can be ridden in 6 - 12" of snow. If (when) I move the country and have some land, I'll definitely have one in the barn if for nothing other than nostalgia. Here is some interesting reading:
http://www.outbackofbeyond.com/gap.htm
or company website:
www.Rokon.com
These two seem to be a match made in machine heaven: