Hi all,   I'm trying to source a spare wheel/tire for a Triad trailer, and I don't really know what I'm doing.  I know that the tires on the trailer now are ST 225-75-d15, and the rim has 5 lugs.  I didn't think to measure the spacing on the lugs and I can't access the trailer now.  When searching online I see rims that are listed as "5 on 41/2 inch". Does anybody know if that's the lug pattern on the Triad trailers?  Also, I see plenty of wheels with radial tires, and just a few bias ply.  I assume that I shouldn't drive with one bias and one radial, is that right?Lastly, bonus points if anyone knows the size wrench I need for the lug nuts.
Thanks so much,      Peter