The On30 wheel sets are high quality parts with superior manufacturing. The main problem is the points axle ends that are too wide to fit the truck side frames currently in production. I find i have to grind the point/taper from the axle ends to make them fit into the trucks. Secondly, the two arms that support the brake beam on the trucks has to be thinned several thousanths of an inch to allow the wheel sets to spin freely in the truck assemblies. Overall, I rate these wheel sets at four stars only because of the adjustments required to make them free rolling in the truck assemblies.
Axel length is 29.71 mm or 1.16 inches
Wheel diameter Inside of the flang 13.79 mm or .54 inches
Using the Wheels on old 0n3 trucks.
We have over 100 pieces of revenue bearing rolling stock all DRGW and RGS prototype plus around 15 caboose, most are Sanjuan but all wheels have been replaced with SJM's metal wheels and most with their trucks too. AS MMR
Very nicely done wheelsets. Black plastic (?) centers with nickel silver tires. Readable foundry marks on the wheel. Very free rolling. Would like to see them in brown or "primer" red.