Richard J Kinch wrote:

Duane Bozarth writes:

Well, if it has tension springs on each side and they're not matched or
tensioned, evenly, "balancing" them so they match force will certainly
go a long way....

"Tension" spring? Do you mean extension? Or torsion? Most doors use
torsion springs.

I don't know about "most"....I'd grant "many" but have no data on
fraction of total installed base. All the ones I currently have are
not torsion, although have had previously...