NMRA Standards?

Discussion in 'Getting Started' started by tetters, Mar 27, 2008.

  1. tetters

    tetters Rail Spiking Fool!

    This is not thread to bash said aforementioned standards.

    Rather, and although a new comer to the scene, I've noticed that despite the standards there seems to be some slight differences. I found it curious that the only cars that seemed to be "sketch" on my trackwork were the Athearn RTR cars I've purchased. I have a couple of 40' reefers and they would rock like a ship at sea when pushed over one of my crossings. So this evening, I went out and picked up a package of Kadee wheels. Enough to do three cars.

    What a difference swapping out the wheels made. They now roll across the crossing like butter, even at a good clip. The only obvious difference I can tell by looking with the naked eye is that the flanges on the Athearn cars seem to have slightly fatter, rounder flanges. By comparison, the P2K, True Line, and now Kadee wheels have thinner "sharper" flanges.

    Now I know, I'm an odd man out here with the handlaying. However, I've been meticulous with my trusty NMRA gauge and found it curious that one particular brand of wheel would not seem work well when everything else seemly does. This is even if adjusted and checked with said gauge and seeming to be within spec.

    What I wonder is if others have encountered this situation with a particular brand of RR product. I'm curious to hear about other people's experience here and if there is any validity to my thoughts.
  2. nachoman

    nachoman Guest

    Did you check the gauge of the athearn wheels? I had some wheels that would not make it through a turnout I layed, an turns out they were very slightly tight in gauge.

  3. tetters

    tetters Rail Spiking Fool!

    Yep. :mrgreen:
  4. doctorwayne

    doctorwayne Active Member

    I'm not familiar with the wheelsets on those cars, Shane, but there's a chance that all of the wheels might be in gauge, but might also be in different positions on the various axles. For instance, if the lead axle has the wheels closer to the left end of the axle (but still in gauge), and the second axle has its wheels towards the right end of its axle (but also in gauge), the truck will be slightly skewed as it moves down the track. On plain, straight track, this may not be noticeable, but the complexities of even a well-made turnout will quickly point out this type of deficiency.

    The Kadee wheels are mounted on a shouldered axle, which not only automatically gauges them, it also ensures that both are equidistant from the ends of the axle, eliminating the skewing problem.

  5. tetters

    tetters Rail Spiking Fool!


    See now I hadn't even thought of that. It makes perfect sense. I do like my Kadees though! Thanks. :mrgreen:
  6. Russ Bellinis

    Russ Bellinis Active Member

    One thing to watch out for with Kaddee wheel sets installed in plastic trucks is that the kaddee axles are plastic while kaddee trucks are metal. Plastic axles in plastic truck side frames tend to wear out the side frames. A friend who used to own a hobby shop built a layout around the roof inside the shop to have trains running. He had a derailment of an Athearn car, and when he pulled it off to inspect it, the Kaddee axle had cut a hole in the bearing detail on the Athearn side frame! This is not an issue that I would worry about, except to inspect your trucks from time to time. He was running the train 10-12 hours per day, 7 days a week; so the train got a lot more wear than you would see on a home layout.

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