[ethbr1]

See sibling comment above about the variable counterbalance needed for a normal right-angle tracked garage door.

You'd have to match the counterweight to the varying load (i.e. garage door effectively gets "lighter" the more its raised).

[mhb]

Counterweight = a length of chain that lands in a bucket as the door goes up.

[ethbr1]

That'd be feasible for new-build uninsulated steel doors, but 200+ lbs of chain for wood doors is a lot.