I bought some of the Exact Rail 36" wheel sets to use on my Micro Trains heavyweights. I added them to a trio of NP coaches, but the wheels bound and didn't roll well. Hmmm. Out with the micrometer, The outside face of the wheels are 0.457" And the space in the truck frame is only 0.4335" !! Ah ha! So, out with the #11. I make a gentle cut at both ends of the area I wish to remove. This little cut acts as a stop so as I shave delrin away, it is easier to control. This pic kind of shows how much material I had to remove, And a before and after. The left truck is modified, the right truck is not. The difference is obvious, and the free rolling is great!
I would believe that overall length is an issue. What would happen if you filed a little off each wheelset pointed end? Somewhere out there used to be a little device which could be used to clean or enlarge axle end pockets. I wonder if such can still be had? Or was that just an HO item?
Point to point is exactly correct. I will get a pic of an IM wheel next to the Exactrail. The tread width is a LOT wider.
The ExactRail example does not come across well for me. Wide tread, large flange with a bit much angle/taper. I can see a bit of shoulder on the bottom inside, which has me curious about gauge. I can now see why you had an issue.
Micro-Mark has the device that looks like a center drill for the pockets and has restart selling spreader tools. I will be ordering them for my HOs. They don't have the same for N.
The ER wheels are well in gauge and the flanges are nicely scaled. The point width is the same as MT and IM. They track well, when they have freedom to roll. Hidden under a heavyweight car the width of the tread isn't distracting. The point trimmer available on HO and O isn't available anywhere in N. I suppose a fella could get a bit carried away and wipe out a truck frame rather quickly.
The problem here is that there is eleven different axle lengths in N scale wheels. Some manufacturers have multiple lengths(Atlas). The MTL are on the small side. This makes mixing & matching a bit of a challenge. The Exact Rail you show has very little point. This will cause the wheel side surface to rub on the truck frame on applications where the axle might fit. It points out how crazy this whole issue is. As usual the IM wheels look to be better suited to deal with the inherit variabilities in the process. What is there about the Exact Rail wheels that make you want them?
Exact rails were available when I needed some last year, and no one else had any. Sooo.... the 32" do work ok in the freight trucks.
I keep a note in each box as to which truck frame and wheel set is installed. Helps point to what works and what gives me troubles.