I am in the process of changing all of my rolling stock to metal wheels. I am trying to find out what the wheel sizes are for the Walthers 89’ Auto Racks and the Walthers 86’ Auto parts cars. They look like 28" but I had been told they may be a 30". If there is a list some where of what sizes are used on HO scale cars it would be very helpful.
Thank you.
I though they use 30 on rolling stock and 33 on passengers car. But that might not be right.
George,
Many of the TTX trailer flats and auto cars use 28" wheels(30" may be on some). This was done for vertical clearance reasons. Most US freight cars have either 33" or 36" wheels(36" wheels on 100 ton capacity cars). Passenger cars usually have 36" wheels.
Jim
I will have to order a few 28 and 30 inch wheel sets. I have already replaced over 200 cars but still have many more to finsh including about 35 auto racks and auto parts cars. I have ten Accurail 89’ flats I need to change and I think they are 33 inch wheels but I will have to check. Thank you.
George,
Be aware that your fleet of TTX cars may have 33" wheels in them now(and ride a little high). Replacing them with 28" wheels may force you to change couplers(now too low). Also, not all axle are the same length - Do not go out and buy a lot of wheel sets until you have done some serious testing.
Jim
Wheels the REAL traincars used was based on weight and tunnels. MODELS use 33" ( freight) 36" (passenger) and based on reducing costs
Replacing with prototype sizes (28" or 36") will change coupler heights.
WHY don’t model manufacturer’s use the correct sizes?
1.It’ll cost more, but not sell more.
2.85% of the modelers won’t know the difference.
If I remember correctly, I read an article in MR about this and the part I recall goes something like this:
Truck capacity in tons/wheel diameter:
<50 Ton/28"
50-70 Ton/30-33"
70-100 Ton/36"
100-125 Ton/38"
There are exceptions, one line had some covered hoppers with 100 ton trucks but 38" wheels. Supposedly had something to do with “spreading out the weight” on thier light rail, whether or not it worked another matter. Many heavyweight passenger cars had 36" wheels even though (if you do the math) the weight formula would call for 30-33" wheels. However, given the high speeds they ran, the larger wheels will turn fewer revolutions per mile, and reduce heat buildup and wear and tear. It could also go back to weight issues when on light rail. On the other hand, if running a 5 unit well car, you would have 70 or 100 ton trucks on each “end”, and 125 ton trucks on each “joint”. Thus, to be correct, you would run 33-36" wheels on each end truck, and 38" wheels on the middle trucks.
The 86’ boxcars probably have 70 ton trucks, so one should install 33" wheels. The auto racks probably have 50-55 ton trucks, so one might install 28-30" wheels. Then again, you can’t really see under these cars all that much, so I might be inclined to use wheels of different sizes to adjust for coupler height.
Brad
Try bringing one of the stock axles with you to your LHS. Then compare the size of the stock wheels to the metal wheels, and get whichever wheels are closest in size.
frisco - Measure them. Invest in a caliper, measure wheel diameter and axle length.
I don’t have a clue really, but good luck with replacing these. I replace all of my wheels with Proto 2000 if your looking for a good brand.