Last Updated: 31 July 2003


By Max R. Robbins, Jr.

Why upgrade your rolling stock?

Here are a few reasons that apply- fewer derailments; better rolling equipment; longer trains; more reliable connections between cars; and overall better operations. This applies equally to your freight cars, MOW equipment, and passenger cars. This is based on building and running various brands of HO rolling stock from the very cheap to craftsman kits over the years.

How can you achieve fewer derailments, better rolling of equipment, and longer trains?

Everyone should agree that the wheels need to be free rolling (no drag), the trucks free of flash, the wheels in gauge, and the trucks properly centered on the car. Then there’s the idea of the Three Point Trucks. It’s recommended from several sources that one truck be tightly mounted so that it can only swivel side-to-side and that the other truck be loosely mounted so it can swivel and rock up and down. This is supposed to help the car track better over rough track. My answer to that is to rebuild the track. Most of my rolling stock has both trucks mounted so they can only swivel from side-to-side and I’ve seen no real problems with the cars tracking and not derailing. I’ll also state that my track work is far from perfect. Most plastic wheel sets do not meet the NMRA recommended practice (RP-25) for contour. Most plastic wheels have a very sharp edged flange, which is more likely to pick the points in a turnout than a wheel that meets the contour. If your layout doesn’t have any turnouts (switches) then you don’t need to worry about this, however, the rest of us need to consider changing to a wheel set that meets the NMRA recommended practices. Of course if the wheels keep picking the turnouts it might be time to check the turnouts. The better your track work the fewer problems you’ll have with your rolling stock.

Part One – Check/Fix the trucks/wheels

After each car is done it will roll easier which will allow longer trains with minimum derailments. This applies to all of your rolling stock. Each piece of rolling stock, regardless of manufacturer or cost of the model, needs to have its trucks checked for the following:

If you insist on using the plastic wheels sets do the following: Examine the wheel sets and remove any flash found. Remove any little nibs from their backside; now roll the wheel set on something flat. If they roll smoothly, install them in the truck and roll them on the flat surface again. If all checks out, move on to the other set. Athearn wheel-sets are usually close to gauge, but most are also unacceptable for heavy operation. The NMRA standards gauge is used to accurately check wheel gauge. You must also check to see that the wheels are centered on their axles. This is where the small ruler comes in. If the wheels aren’t centered, they will climb rails, points, and joints basically anything they can and will. Next, check your under-frame bolsters. Here is where you can reduce wobble. Remember the three-point mount. Using a horn-hook coupler, check it for flash around the pivot hole, and placing the round pivot end over the bolster pivot, bottom it on the bolster pin. Take your #11 knife and carve off any of the bolster pin that is sticking out past the horn-hook. Do this to both ends. This will allow you to tighten the mounting screw.

Part Two – Weigh the cars

Make sure each car meets the NMRA recommended weight. See Recommended Practice RP-20.1 Car Weight. Most cars are too light and won’t track easily. Kadee’s Ready-To-Run cars are an exception. For HO the recommended weight is 1 oz. plus ½ oz. for each inch of length. This means that a scale 40’ car should weigh 3.75 oz. Weights are available from many sources. I use A-Line lead weights with good results. This also gives more realism to the number of cars a locomotive can actually haul.

Why add weight to the rolling stock?

Lots of people say ‘I’ve never added weight to my cars and they don’t derail.’ This is probably true, however, if your going to go to a club/module group that does operation it’s probably a good idea to have your cars meet the NMRA weight standards. I didn’t do this for a long time, but one day I started weighing the cars and found that even with sloppy track work (modules) the cars stayed on the track much more than when they were too light. Of course the better your track work the less of a problem this will be if you’ve upgraded and improved your rolling stock’s trucks. Another way of looking at this is if Kadee and other manufacturers do add weight to their rolling stock to meet the NMRA RP then this idea must have some validity and why did the NMRA create the RP?

How do you achieve better connection between cars?

If you only operate on your own layout or only with your own equipment you can keep the horn-hook couplers, however, most clubs require knuckle couplers. Knuckle couplers gives your better operation and ease of uncoupling where you want without having to use a special piece of track.

Part Three - Replace your horn hook couplers with knuckle couplers.

Remember the better you build the piece of rolling stock and pay attention to details (flash removal, smooth rolling trucks, weight, etc.) the better the piece of equipment will perform and the fewer derailments you’ll have. Now a lot of people will say that this is very expensive. I’ll agree it’s not cheap, however, checking the trucks and correcting those problems should only cost you time. Converting to metal wheels, adding weight, and changing couplers will cost, but the end result is that your rolling stock will perform better and you’ll spend more time running and less time re-railing. Remember you can do this in stages and will eventually get all your rolling stock done.


NMRA Standards Gauge

“The Tool” – Available from Loy’s Toy’s (

#11 X-Acto Hobby Knife

Kadee Tap and Drill


Knuckle Couplers – Kadee, McHenry, Intermountain, EZ Mate, Accurail, etc. A-Line Weights

Metal Wheels – Kadee or Jay Bee

2/56 screws

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