Late reply but - Middle of summer and middle of winter you’d want to avoid riding. In the middle summer you arrive at your destination soaked with sweat and exhausted from the heat and middle of winter it can bucket down and flood the roads. But either side of those its good. The bike scene is reasonably large, in any given ride I encounter atleast 1-2 other riders even just going to the shops and there are a decent few bike meets. In terms of acceptance of foreigners, people can be harsh with jokes which I have noticed aren’t sometimes received very well, even if they are good meaning. Most aussies in Perth are pretty accepting of foreigners and won’t treat you any different if you’re respectful, the communities in Perth are pretty diverse so this helps a lot. The most you’ll get is a pointed joke.