Hi Gustavo,
Welcome to Sweden and Göteborg. I meant to reply earlier but somehow forgot it. ..And somehow remembered it today.
Anyways, a good place to start is to look at the calender (
http://happymtb.org/kalender/) and find suitable announced rides there. It has been a bit slow during the winter but have started to pick up now (there's one today f. ex.:
http://happymtb.org/kalender/1426/). You will find a brief description, where 'happy easy' doesn't necessarily mean the trails will be easy, but rather that the pace will be somewhat slower and the group will be sure to stick together and make sure that everyone gets to breathe (or so I've heard).. The ones omitting the 'easy' monikier can have a higher pace, and will typically wait for everyone, but when the last guy joins the group, they will take off in high speed again. :-)
There's also facebook groups anouncing rides (f.ex. the group "Cykelgubbar"), let me know and I can give you some more pointers for those as well.
I'd be happy to show you around a bit as well some day, I typically ride in Änggården both after work in weekdays (~16-18 or so, no need for a lamp nowadays) and the weekends. Just drop me a PM and we'll arrange something.
