Did you do a search on the board or the net? Did you type in Velke online sales or Velke sales? I mean I can't see how if you did a search you didn't find it online. I think landscapers supplies sells them. J Thomas should sell them also.
There is another kind out there that you may want to look at. I cannot think of the full name but part of the name is Jungle -----.
Some of the dealers in our area tell me their customers prefer them because they have bigger tires and are better constructed.
they do cost more, but not by much. I am thinking of getting one of these.
Jungle Wheels. I use them on my Turf Tracer and Ransomes walk behind . If you run a hydro then Jungle wheels are the way to go. On belt drive mowers I prefer the 1 wheel Velke because it does not jacknife when you pull the mower back (I rarely use reverse gear on my toro belt drive).