I have both kinds and have never noticed any differences besides size. What do you all think? I mean, semi-scale looks better, but I just don’t see the added expense.
Don’t spend the extra. This hobby is all about choices and compromises. Many of which have to do with available funds, at least for me and probably many others. So spend your dollars where you get the greatest satisfaction.
In my case, I upgrade plastic wheels to NWSL metal wheels, but I don’t upgrade metal wheels that come with the trucks. Others are just fine with plastic.
Enjoy
Paul
Semi-scale wheels have a narrower tread (width) than the NMRA standard. Still wider than the prototype, they definitely are better looking. Their appearance advantage is highest on high-riding cars like drop-bottom gondolas and tank cars and where the wheels are extremely close to the car ends such as on ore-carrying hopper cars.
S-S wheels are less tolerant of excess track gauge and there is a tendency for them to drop a bit in turnout frogs unless they are built to close standards and/or the depth matches NMRA RP-25 flange size.
Mark