N scale model railroading has evolved quite a bit over the years, and I've enjoyed having a living-room 4x8 foot layout since 1980. As I've gotten more interested in operations over the years, I kept having derailments on my mostly Peco switches, which discouraged me considerably, and kept me focused on my basement HO layout. After seeing the benefits of metal wheelsets on my HO layout downstairs (heavier weight, cleaner track) I tried installing some N scale Fox Valley wheelsets, not realizing that they were a narrower tread than required by the older Peco switches. After that made things even worse, I tried the Micro-Trains "metal wheelsets". But they have plastic axles, which would sometimes pop out of the plastic truck sideframes. And the "metal" is coated with a brown coating that looks like it would wear off over time and contaminate the rail head. I went ahead and converted most of my fleet of cars with the MT metal wheels anyway, but still would have derailments. Years went by.
Then a friend let me know that Fox Valley (now a division of ScaleTrains) made a line of "standard" tread metal wheelsets with metal axles, as shown in the picture above. He said that he converted his whole fleet to them and had no derailments, even on older Peco switches. So, I purchased some and tried them out. I noticed that their flange is much narrower than the MT (and Atlas, etc.) flanges, more like the original plastic "pizza-cutter" wheels of old. I think that as a result they really do track better. And their extra weight, low down in the car, from the metal axles, is an extra bonus, too. I think they roll a lot better, too, with the metal axle point in the plastic truck sideframes. I have now converted most of my fleet to these precision-machined wheelsets, and recommend them highly. Just make sure you pay careful attention to three variables when ordering them: the axle length, the width of the tread, and the diameter of the wheel. The ones I'm using on my mostly Micro-Trains cars are 0.540" axles, "Standard Wheels", with 33" diameter, stock number FVM 3310-100.
The other aspect of reliability I'm starting to realize is that with 12" radius curves and a 2% grade on my mainline, longer cars can cause "stringline" derailments on longer trains. I'm reluctantly starting to avoid using the longer cars now, or at least keeping them at the rear end of trains, to avoid those types of derailments. Above is a photo of one such derailment, and you can see that an empty center-beam flatcar, or maybe the long high-center-of-gravity tank car was probably the culprit. If I ever build another N scale layout, I hope to have much broader curve radii, like 18". When I designed this one in 1980, 9" radius was common on N scale layouts and I thought I was being very conservative in using a 12" minimum. Live and learn!
