# Min radius?



## Gansett (Apr 8, 2011)

Will a 2-8-2 or 4-8-4 negociate 18" radius curves?

TIA
Jack


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## waltr (Aug 15, 2011)

Which make?


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## Gansett (Apr 8, 2011)

Bachmann


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## tkruger (Jan 18, 2009)

It is questionable. If that is a Spectrum by Bachmann it may not. If it is an entry level then it might. Do the inner drivers have flanges? If so it is less likely to make it. Post some picks. I have a 2-6-2 Bachman and it has no issue. On 15 it starts to bind. My Bachmann 4-4-0 American cannot make anything less than an 18.


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## raleets (Jan 2, 2011)

Jack,
I have a 2-6-2 Bachmann that takes 18" curves on a figure 8 like a scalded dog. Can't comment on anything other.
Good luck!!
Bob


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## Maddog (Jan 14, 2016)

Grab some flex track and try it out. 

Athearn's Blue Box SW1500/SW7 will take about a 9" radius.


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## mesenteria (Oct 29, 2015)

It is always, and I do mean ALWAYS, best to mock up the curve you'd like to use and then run the real thing over those curves. Not just by itself, but trailing and shoving a string of rolling stock. Sometimes you learn that the curve is too tight for the engine and tender, or it's too sharp for diaphragm-equipped passenger cars like Walthers' heavyweights. So, I agree with Maddog.

Just so you know, it is highly unlikely that any of Bachmann's steamers will not negotiate an 18" radius curve, unless it is plainly and boldly stated on their literature/manual for the item in question. But I could be wrong, and in the absence of a statement to that effect, the best way to get empirical evidence of your own is to do your own trials.

Finally, while they will both probably work, the 2-8-2 with its smaller drivers set closer together, and the axles on the larger-drivered 4-8-4 separated that much more, the 4-8-4 might struggle a bit, derail more often, particularly at speed, and it will look quite a bit more 'toy-like'. Some of us have a lot of tolerance for such appearances, especially when we're new to the hobby or quite constrained by space or finances. But if you can possibly eke out another two or three inches of radius, you'll be a lot happier and the engines will perform somewhat better.


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## Maddog (Jan 14, 2016)

mesenteria...thanks for adding the additional info. Keep an eye out for binding with rolling stock. Longer cars may derail when coupled together. Also watch the weight of your cars. The NMRA has recommended practices for car weights. A light car may be more prone to derailing.


_"... the one thing around the railroad that worked every time was a derail."


"... It is easier to answer a dumb question than to fix a dumb mistake."
_


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## CTValleyRR (Jul 26, 2014)

We do know that we've resurrected a 9 year old thread here, right?


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## cid (Jul 3, 2014)

Happening a lot lately...


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## Maddog (Jan 14, 2016)

It's still relevant.


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## CTValleyRR (Jul 26, 2014)

The topic of minimum radius is always going to be relevant, but that doesn't mean that we shouldn't exercise care in which threads we chose to bring back, and especially HOW we bri g them back. If you bring them back with a comment that indicates that you KNOW it's an old topic but feel it's worth taking another look at, I don't think too many people would object (I know I wouldn't). When, as now, someone offers some advice on an question that was asked almost a decade ago, then not so much.


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## Maddog (Jan 14, 2016)

How about deleting old topics? Maybe anything that hasn't had a post in over a year gets dropped? That might help to cut down on the infinite number of topics here.


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## CTValleyRR (Jul 26, 2014)

As you point out, the old topics often have relevance, so deleting them would not be a good idea in my mind. Several of us have recommended locking anything more than a year old, but without result.


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## Maddog (Jan 14, 2016)

Okay, that will work for me. Topics will be locked if no activity after one year. Then we wouldn't be having discussions about old topics instead of minimum radius.


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