He first began riding at the age of 12 and was brought to the world of Freestyle BMX by Ron Kilmer, who appeared with Taj in the celebrated "Road Fools" videos.
After years riding for the company Hoffman Bikes, he started Terrible One with Joe Rich, by releasing the "Barcode" bike frame, largely based on Taj's signature bike design at Hoffman Bikes.
It was rumored that Taj was displeased with the way that his signature frame was holding up after Hoffman Bikes moved their manufacturing overseas, and that he didn't want his name attached to something that he felt was of substandard quality.
Taj was also sponsored by Etnies, where he designed several signature shoes as well as appearing in the widely recognized "Forward" video featuring the Etnies BMX team.
In late March 2006, Taj announced, that he would be leaving his half of Terrible One to Joe Rich, via the company's website. He cited the stresses of running a company as a key factor in this decision.
In early 2008 Taj announced that he would be riding for Giant bicycles. Not long after a back injury and resulting surgery forced him to retire from a 18 year professional BMX career.
In 2010, with the help of Odyssey BMX Taj launched an all-purpose road, commuter and town bicycle company called Fairdale Bicycles.
Taj has appeared in numerous BMX videos such as Etnies FORWARD, Etnies GROUNDED, Odyssey Electronical, UGP Face Value, Primo Made In Taiwan, ANTHEM, Road Fools 1 and 5, and Hoffman Bikes - Madd Mat.
Taj Mihelich is an animal welfare advocate who has become vegetarian in addition to his pronounced sport career