The road from Croydon to Normanton is sealed, as is the road from Normanton to Cloncurry.
I traveled through in April 2014 on the Goldwing. Quite a bit of it is one lane. Smaller 4 wheeled vehicles respected my two wheels and let me share the one lane. I did not take any risks with large trucks and road trains and got right off the road and almost stopped. thankfully I didn't see too many of them.
I stayed overnight in Croydon at the caravan park. An interesting time. At opposite ends of the caravan park, there were two competing families with Boom Boxes. They had them cranked up ALL night. I only had intermittent sleep.
Just warning you!