the TT is a stand alone event, with a somewhat open entry. Most of the top riders also participate in street circuit racing. Same style of racing as the TT, in that they are held on actual roads, but on different courses around Ireland and the northern UK. Basically you have to have experience in those races to enter in the top levels of the TT. Basically the most traditional form of motorcycle racing.
This is one of those types of races, https://en.wikipedia.org/wiki/Ulster_Grand_Prix
But I've never been on a motorcycle. I was out for a month on doctors orders because my job is physically demanding on the place where I got injured; if I chopped off a finger, I could still perform the job fine. And I do know that ribs heal quickly.. don't know about the other two.. Is.. it.. OK to ride a motorcycle.. like this? Please tell me it is. D: