There is a lot of chatter on the Web about which size Blur to ride. The line between a large and medium is exactly the height of the average North American / European male, 5’10″.  Makes sense that so many are asking which size to buy. I have ridden both a medium and large. I am 5′ 10″ with a 32″ inseam. The medium is too small. The cockpit is cramped and not fun on long rides. The large does not feel that much bigger but does give you more room. The large 2011 Blur LTc that I ride came with a 90 mm 6 degree stem.  I replaced it with a Race Face 70 mm 6 degree and the fit is perfect.

Santa Cruz Blur Size Chart

Before: Large Blur with 90 mm Stem

After: Large Blur with 70 mm Stem

Of course if you have the opportunity to test ride both the medium and large, you should. But if you are an average dude, go big (Large).