In light of the recent Blue Square-rated Jubilee Trail Extension project completion, I feel it is a good time for an education on trail ratings, per IMBA. This will likely be a refresher for some of you but it is a good reminder, nonetheless.
Also, refer to this page at IMBA.com that explains the process of rating trails.
In addition to the table above, a few other factors need to be considered objectively; one being the difficulty level of other trails in the area. Based on ScoCoPa, Illiniwek, and Sylvan, the majority of the Blue Square and Black Diamond rated trails at Sunderbruch should be considered Black Diamond trails. However, in the interest of progressing rider's abilities we've taken other trail qualities specific to the system at Sunderbruch into consideration when rating the trails.
The Jubilee Extension is a true Blue Square trail based on the criteria described by IMBA. Each obstacle is easily avoidable. Each unavoidable BRIDGE is well over 24" wide and each unavoidable Technical Trail Feature (TTF) is wider than 1/2 the height.
There is no shame in dismounting and walking a section of trail if you feel uncomfortable. In fact, it is encouraged, and nearly demanded, that you do this. Progressing your skills as a mountain biker is one of the biggest draws to this sport and by far the most fulfilling. A trail system with varying levels of difficulty as well as a mix of technical features invites riders to progress their skills.
Remember when you first learned how to ride a bike? Fell down, got back up again until you figured it out, right? Same principle applies on the trail.
Just try to do more figuring out than falling down.