@RJT posted:John I would try shimming the wheel set first to stop them from shifting and then see what has to be done to cure the issue. Shimming them may reduce the amount you have to taper the wheels and it may to consider replaceing the wheels with thinner units also. Just my two cents.
Pretty sure just shimming them isn't going to do the trick, there isn't enough play to solve the problem with those fat wheels.
Replacing them isn't in the cards as they are not standard wheelsets, and I have no idea where I'd find something that would fit the tender. The axles are a non-standard size for sure.
@Bruk posted:Id taper the blinds sets to be the same width as the wheels with flanges. By width I mean the surface that be in contact with the rail.
That's my initial thoughts, but I was also wondering if I shouldn't start the taper a little sooner as I want it to be a gradual taper to allow the wheel to slide onto the rail in curves if it's off to the outside. I've seen this mentioned in the past, but I sure can't find it now.
My sense was maybe to start the taper about where the flange starts on the flanged wheel sets, which would make the taper cover about 40-45% of the wheel surface. I'm thinking around 20 degrees of taper, but the reason I'm asking is I don't want to screw up the only set of wheels I have! 
