Epic Eric pointed me to Curiak's blog where it says his big ride to Nome was, "1,100 some miles, over 21 days of riding. Knik to Nome on the Iditarod trail. Purely self-supported."
Pretty neat. 50 miles per day. Same speed as the skate skiers Kelley and Baker who may also have done their trip self-conatined (let's pretend they did). Curiak's tried it a bunch and has a decade of experience riding on that long snowmachine trail. He's a bad-ass biker in other ways, too, outside of Alaska.
It's interesting to me that he made about double the distance that Jason Geck and I made on our Arctic 1000 unsupported walk in the arctic in the same amount of time. I think we are sort of stuck with a maximum amount we can carry and that feeds us for about 3 weeks and the rest is decided by speed (given determination, skill, and endurance).
In short, mountain bikes are about twice as fast as feet in long distance AK wilderness travel. For example, in the Alaska Range traverses of 1996, the hikers averaged pretty much half the speed of the bikers....and this seems to hold true here, too.