A Link Wheel is a network of websites (commonly used by Web 2.0 sites) and blogs connecting to each other, which will link them to your website and helps your site to rank up in Google’s front page. The traditional Link Wheel goes like this:
The networks of microblogs and web 2.0 sites can vary from 6 to as much as 116 for each link wheel.
As discussed earlier, this traditional diagram is mostly susceptible to being tracked by Google. This is not entirely illegal, so to say, but it is not verily acceptable in the eyes of Google.