MINIMUM CURVE FOR 20" CARS

If you're running 3-rail cars with hi-rail couplers, they'll negotiate O-72 curves but won't look as good as they would running on O-84 or O-96.

I don't own any scale 80' cars (20 inches), but the 18" cars I have all have no trouble on O42.  the first set of 80' cars I could find was a set by williams and they say O54 on the box.  

Now I will agree that even the 18" cars look silly on O72, but they will stay on the track just fine even tighter.  

I have several sets of 80-84' scale cars and the manufacturer rates them for 054 curves. I've never tested that as I only run them on 072 or higher. As others have pointed out, 20-21:" cars look out of place even on 072 curves; they look best on 084 or better. A lot depends on your layout - if you have long straight runs with curves at the ends, and viewing is primarily of the straights, that may not matter. If your viewing area emphasizes the curves, you may find that the longer cars don't look good even if they do make the curves. One trick that helps longer cars to navigate tight curves - if you have room, use one or two sections of wider curved track on the entrance and exit to your tightest curves (i.e. a piece of 084 at each end of an 072 curve, or a piece of 072 leading into and out ofds an 054.curve. 

I am running the scale Lionel cars. I have 0-89 and 0-96 curves and in my opinion  I would not go smaller then that because of the overhang you get the smaller radius you go................Paul

My 2 cents:

I have been running my Big Boy and now Pocahontas and its cars on O72 with no issues; however, they would look a lot better taking the curves on larger diameter track.

RickM46

I run my 21" cars with body-mounted Kadee couplers on 072 curves, if I look straight down I can see the centerline of the track when a 21" car goes around the curve.  If that bothers you, go to a larger radius.  I also have a couple of 18" cars, there's not much difference between how much overhang there is between the 18" and 21" cars on an 072 curve.

My 21" cars with body-mounted Kadees WILL NOT go around 054 curves without derailing.  One thing you need to look out for is the flat ends (striker plates) of the diaphragms catching on each other if they're too close.

I have run 21 inch Atlas passenger cars on 042 curves with an SD-45 engine, remember the engine is a factor to be considered too. From my experience a larger engine will allow a larger passenger car to run behind it.

The other set of passenger cars is a K-Line 16 inch interurban cars(heavyweight cars by K-Line too in the same size), have run them on 036 curves but K-Line recommended 042 curves.

There are a few factors to be considered; first of all "who made the passenger cars?" second "what size passenger cars and how many wheels?" third what size engine?

Lee Fritz

These cars are Williams aluminum cars. I should probably pass on them since my largest curve is 072. Thanks for all your replies.

What's your smallest curve that you want to run them on?  They should work (may not look) fine on 072 curves.

It's been stated before-it's personal preference.

Everyone has an opinion on what looks acceptable to them.

I run my Ca Zephyr cars on 096 curves and they still have overhang on the curves but I cant go any bigger.

Mikey

Had I the space, i'd make bigger curves but I don't so i'll just keep what i've got. It's not that I need them, I just want them which is a big difference as we all know.