It is easy to log in Biker Planet on the homepage if you are already a member of the site. You can see the login box on the index page which is under the search section.
If you use a mobile to visit BikerPlanet, you can see the “Login” button of top right corner of your mobile screen. Click the bottom and you will see the login box.
On both PC version and mobile version of Biker Planet, you can see “Log in with Facebook”. Yes, you can log in BikerPlanet with your FB account as long as you have connected it with BikerPlanet.