Mine are fitted to a folding RIB but I've owned a SIB and cannot foresee any problems with folding once the arm and wheel are removed.
The original assembly has a pivot bolt but to ease removal of the pivot I replaced it with an 8mm stainless pin like this
or you could replace the bolts nut with a stainless 'wing nut'.
As you can see the assembly is in good condition after 8-9 months salt water use, about the same amount of outings but hosed off afterwards.
Good bit of kit and if mounted low on the transom will allow the fitment of even larger wheels if required as shown here (middle and right assembly's)
Ignore the assembly on the left......or it maybe another alternative you may have overlooked......they weren't suitable for my set-up.