Originally Posted by sanderd
or is this question waaay to unspecific to get a decent answer?
but I will try to give you a specific one ....if I'm right to think you will stay in the western Half of north america and visit only few popular attraction.
from my experience, it take me 1 moth and this give me enough tome to visit many place bettween alaska and mexico including those popular ones : Dawson city(YK), Vancouver island, Canadien rockies (Banff-jasper-waterton),calgry,yellowstone np,bonneville saltflats, las vegas,grand canyon,monument valley,archer np, bryce canyon,dethvalley, L.A.(hollywood), road 1 (califournian coast(Hearst castle)), sequoia np-king canyons np, redwood np, san francisco.
I was ridind too fast, I didn't relax, but 90 seem enough if you don't plan to ride outside this area
Enjoy your ride