What type of plane/engine? Great for trimming brush on new runways, takes a beating and keeps on ticking, Pulls hard off the line. If you are on grass/tar strips and don't plan on a lot of prop abuse the wood props are doing pretty good. Depends on mission. For proper propeller to ground clearance the aircraft must be equipped with an approved combination of wheels and tires that provides a minimum clearancebetween the ground and the center of the axle of 9-3/8 inches, or having extended landing gear per Cub Crafters' STC SA00411SE installed.
DENNY
This is the controlling regulation.
CAR Part 3.422
§ 3.422 Propeller clearance. With the
airplane loaded to the maximum weight and most
adverse center of gravity position and the
propeller in the most adverse pitch position,
propeller clearances shall not be less than the
following, unless smaller clearances are properly
substantiated for the particular design involved:
(a) Ground clearance. (1) Seven inches
(for airplanes equipped with nose wheel type
landing gears) or 9 inches (for airplanes equipped
with tail wheel type landing gears) with the
landing gear statically deflected and the airplane
in the level normal take-off, or taxiing attitude,
whichever is most critical.
(2) In addition to subparagraph (1) of this
paragraph, there shall be positive clearance
between the propeller and the ground when, with
the airplane in the level take-off attitude, the
critical tire is completely deflated and the
corresponding landing gear strut is completely
bottomed.
(b) Water clearance. A minimum clearance
of 18 inches shall be provided unless compliance
with § 3.147 can be demonstrated with lesser
clearance.
(c) Structural clearance. (1) One inch
radial clearance between the blade tips and the
airplane structure, or whatever additional radial
clearance is necessary to preclude harmful
vibration of the propeller or airplane.
(2) One-half inch longitudinal clearance
between the propeller blades or cuffs and
stationary portions of the airplane. Adequate
positive clearance shall be provided between
other rotating portions of the propeller or spinner
and stationary portions of the airplane.