Hello. I may be of some assitance. I too wear an XL and own a Fly Trekker, I do not own a Bell. I originally bought the AFX-39 Hi-Viz in XL, after its break in period the helmet felt too loose on my head and I really wasn't impressed with AFX's Hi-Viz color. I then bought the Fly Trekker in XL. I purchased it online via RevZilla, they explained to me that the AFX-39 and Fly Trekker are virtually the same helmet except that Fly uses different thicker padding and has a D-strap chin strap. The thicker padding makes for a snugger fit. I am very happy with the sizing and fitting of the Trekker, plus Trekker's version of Hi-Viz is SUPER bright. It is a florescent yellow/green and can be seen from 1/2 mile away. The helmet has good venting and the flip down face shield has no distortion. The helmet is a great bang for the buck!