We've been having some ongoing tire/wheel problems with our 24 row 1770 planter, last year we broke the center out of one rim on a busy state highway and the next day blew another tire out on the same road.  The 9.00-16 implement tires that came on it were only rated for 3,300lbs and the 6 bolt rims were rated for the same weight.  It is now riding on some 11R22.5 truck tires on 8,000lb capacity rims and 8 bolt hubs.  Deere wanted $404 for each of their 8 bolt hubs so I went to our Case IH dealer and got some for a 1250 planter for $182 each, Case IH also used bearings and an axle made in the USA which I'm sure the Deere's wouldn't have been.  Case wanted $356 for each of their rims so I called Hey Wheel and had them custom build me some (needed a 1"+ offset) for $169 and the tires are just used tires our tire dealer had.  I used 3/4x6" flat plate and 4x4x1/2" tubing to build new wheel frames since the stock one's weren't wide enough and were marginal on strength.  The back half of the wheel mounts are angled so that when the planter is lowered it will lower to the same height as before since the new tires are 8" taller than the old ones.  It ended up being a much more time consuming project than I expected but it turned out great and I'm looking forward to see how the planter handles in the field now.