For those who ride in slow, technical conditions, there is nothing better for peace of mind than a bike with a coolant recovery tank (CRT). The design of a CRT isn't that special; it is simply a catch tank attached to the radiator overflow hose. If you get the engine hot enough to boil over the radiator, the vented coolant is caught in the overflow tank. When the radiators cool sufficiently, the vented coolant is siphoned back into the radiator. Virtually all Japanese liquid-cooled off-road bikes come equipped with a CRT system; the problem is fitting one on a bike that isn't designed for it.
We've tried to adapt aftermarket units to our KTMs before and haven't had much luck. Thumper Racing has an aluminum CRT that is easy to mount on the side of the bike below the radiator. Since it is aluminum, it is tough enough to survive in the semi-exposed position. We never even noticed it was on the bike when riding, and it calmed us down when the going was slow. The CRT should fit on any bike with no problem, and at $79, it is a reasonable alternative to boiling out needed coolant and losing it. A CRT isn't for every bike and riding situation, but if you need one, you'll know it!