Cycling in Portland is a very easy very pleasant experience but it lacks some of the visceral elements of a good ride though London plus a few annoyances of its own.
Firstly cyclists in general behave very differently here than London. Portland cyclists behave like cars, they take up lanes, and they don't filter through traffic. In fact filtering through traffic may be illegal here.
Cars are petrified of riders and stay well away. Though because most cyclists ride like they are cars, if you filter or come down the inside there is a significant chance a car/truck will turn across you without looking.
Stop signs, these are at every junction and apparently mandate that you do what they say, that is come to a complete stop. This makes it impossible to have a nice flowing ride and so as a rule I ignore them as far as possible.
I miss the cut and thrust of riding in London, the greater urgency the fast riders and the impromptu races, though my life expectancy is probably higher here!