I don't know what to make of these trucks. The detail is excellent and they roll great. For a couple extra bucks over some Kato's you get an assembly which floats on mini-springs. Definitely interesting. Probably not the toughest wheel set in the world due to that feature. They also made two of my gondolas ride enough higher they went from using center position Kadee whisker couplers to oversets. The higher center of gravity has to off set any advantage the sprung wheels offer.