I hope I can answer your questions.  I have a handicap friend who I put these AirFree tires on his Sun EZ3.  I purchased the Catalina Free Style, 20X 1.75 for the two 406 rear wheels, and the Pocono, 16X1.75 tire.

Airfree will rent you a tire installer.  DON'T use it.  The rear axles are too big.  You will need a couple or three long (long) motorcycle tire irons.  Mine where 16" long.  Better leverage.  I mounted the rear tires on the trike, but you can remove wheels and mount them also.  Use 4 or more Zip ties.  First two ties about 2" apart to anachor tire from moving on the rim.  Then use tire irons to walk the tire onto the rim.  At 1/4 to 1/3 around the rim use a Zip Tie to anchor the tire and work your way around the rim until 1/2 to 2/3 the way an use the last Zip Tie  (Zip tie 8 to 10 inch long).  Just alittle more work with the tire irons and the tire will pop on  the rim. 

Check to see if the AirFree tire is seated on the rim.  Total time to do each tire was ten minutes, but the 16 inch front was different.  This is a small tire and tire irons are the only way to get them on.  Place the tire in direct sun for approx 30 minutes to soften the rubber for install, or place the tire in a oven at 250 degrees for twenty minutes.  Note:  I had to do this because I installed the tire during Winter.  No mess or smell is left in the oven.  Wear gloves the tire is warm not hot and it will install just like the 20 " wheels with Zip ties and tire irons and a few choice works.

 

My tires still look like new after 6 months, but I don't skid them and I slow for curves.   Remember to remove the rim tape.  Air Free has tire install instructions on their Web site. 

My USX uses only 20X1.75 tires.  I have one new 16X1.75 custom psi set at 100 + psi tire.   I will sell it for $20 plus $10 shipping if anyone is interested.

 

Mike    916-663-5878 after 12:00 Pm PCT

Rocklin