Originally Posted by MaestroPNW
the sliding arms don't look like they move all the way out. In fact, the pin needs to be on the outside of the arm to prevent it from moving outwards. Estimating length of the square tube on the base of the arm, effective max distance from the center would be about 8'', not 11'', making diameter around 16.
So drill a hole through the wheel holders about 1/2" from the end and get 22" wheels!