# Noob curved-track radius question



## Mike S (Mar 6, 2012)

If I have a half-circle of 9.25" radius track, where exactly is the 9.25" measured from? Inner edge, outer edge, centre?

Thanks!


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## tjcruiser (Jan 10, 2010)

In HO, track radius is measured to the center (or midpoint) between the rails. I'm pretty sure the same is true for N track.

TJ


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## Mike S (Mar 6, 2012)

That's what I had thought, thank you!


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## Brakeman Jake (Mar 8, 2009)

It's the same in N scale as pointed out.At 9 1/4 in. radius,what brand of track this is?


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## Mike S (Mar 6, 2012)

Atlas code 80.


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## Brakeman Jake (Mar 8, 2009)

Atlas C80 come in 9 3/4,11 and 19 in. radius curves.A half inch difference may not seem like much but if you're planning a small layout it may become a world of difference.


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## THE TYCO MAN (Aug 23, 2011)

Atlas has only made 9 3/4" curves as far as I know.


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## Mike S (Mar 6, 2012)

Couldn't remember off the top of my head. I knew it was 9-something. Either way, the layout might be tight so I'll need to know exactly where to measure because 0.5" might indeed make all the difference


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## Brakeman Jake (Mar 8, 2009)

Track radius is indeed measured at the center so a 9 3/4 rad. will mean 19 1/2 in. diameter.Then the tracks are 3/4 wide (3/8 on both sides of the loop) wich will give you a 20 1/4 +/- of track space needed,running trains dangerously on the edge of the board.A 24 in. wide layout is a minimum and yet I'd have some sort of fence so that eventually derailed rolling stock don't end up on the floor.


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