Check to see if the tire is seated all around both sides.
Check tread wear (cupping or abnormal wear).
Check to see if the tire needs balancing. Jack front tire until it spins free and see if it settles in same spot.
Check to see if steering head/bearings are loose/missing.
Check/service front fork (proper fork oil level, clean oil).
Check front wheel bearings.
Check for front brake hang up.