It is not a "catch"... it is just like the brake shoes in a drum brake.
The clutch shoes are flung out by centrifugal force against the force of springs holding them back... the stronger the springs the higher RPM it takes to fling them outwards and engage the outer drum.
That is called "clutch tuning" by the snowmobilers.
Snowmobile drag racers use stronger springs so the clutch doesn't engage till the engine is at almost maximum RPM... and they... BLAST... out of the hole.
Trail machines engage at much lower RPM because they use weaker springs.
And I would like to hear your definition of a "starting clutch" as you call it.