thurmond maynard is in the fight of his life. diagnosed with als at just 35 years old. >> now i have to lean against something for balance issues. my balance has gotten worse. >> reporter: a husband, a father, als has already robbed him of his career, his passion for dirt biking and eventually, it will steal his ability to walk, talk, even breathe. but thurmond still has hope, because he was chosen for a potentially ground breaking clinical trial, using stem cells designed to beat back the disease. and today, he's about to attempt what he was convinced he'd never do again. >> what are you about to do here? >> try to ride a motorcycle. >> reporter: for the first time in? >> about two and a half years. >> reporter: how's it feel? >> feels good so far. >> reporter: thurmond's convinced he's got a reversal of the devastating symptoms. >> this is the hardest part i had, i couldn't pull the clutch in. >> reporter: it's an astonishing victory. that gives tantalizing hope where once there was none. because this is the brutal reality of a