# Flexible Track minimum radius



## nearboston (Dec 19, 2013)

I will be starting the build on a small HO scale trolley layout soon and would like to get some input on flex track. Its going to start out as a dog-bone style continuous loop, possible expansion in the future, and I'd like to keep the end loops as tight as possible. 

What is the opinion on or experience with the tightest cures using flex? Fyi this will be old LifeLike brass, schedule unknown at this moment.

Thanks in advance


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## FRED On Board (Jan 2, 2014)

I don't have experience with brass flex track of any brand, but I can make a simple suggestion having a satisfying experience with Atlas nickel-silver HO code 83 flex track... A 15 inch radius is possible to achieve with the Atlas flex track but if your trolly's suggested minimum curved track radius is not known, I would suggest you try your trolly on a curved test track of 18 inch radius and if that presents no problems and you need or want a smaller radius, decrease it incrimentally an inch at a time and see if your trolley is able to negotiate the increasingly smaller radii and go from there.

Also, to perhaps state the obvious as a cautionary remark...If, per chance, you may also run typical HO diesel locomotives and freight running stock of 50 or 60 foot scale length at some point in the future, the usual 18 inch radius would be the minimum I would incorporate in layout plans...And for larger wheelbase steam locomotives, longer freight stock and full length passenger cars, often 18 inches is problematic and too tight for these iron horses, prototypical length passenger cars and some of the more modern, longer freight cars. 

Bruce /FRED On Board
ATSF, BN, SP, UP


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## D&J Railroad (Oct 4, 2013)

I would be inclined to say any flex track can be bent to a pretty tight radius, i.e. less than 15" or smaller. You might have problems with the rail separating from the ties as you increase the stress on it so nails may be needed to hold the rail to the ties.


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## DonR (Oct 18, 2012)

nearboston said:


> I will be starting the build on a small HO scale trolley layout soon and would like to get some input on flex track. Its going to start out as a dog-bone style continuous loop, possible expansion in the future, and I'd like to keep the end loops as tight as possible.
> 
> What is the opinion on or experience with the tightest cures using flex? Fyi this will be old LifeLike brass, schedule unknown at this moment.
> 
> Thanks in advance


I used Atlas flex on a trolley layout several years ago. I do not recall the
end radius but it was very tight, had to have been 15" or even less. The
trolleys can manage very tight radius. They are designed to round
street corners.

I notice you plan a dog bone layout. Will that be a dog bone
shaped oval or an actual dog bone with reverse loops at each
end? 

If the latter, do you plan to use overhead wire for trolley
power?

Don


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## nearboston (Dec 19, 2013)

DonR said:


> I used Atlas flex on a trolley layout several years ago. I do not recall the
> end radius but it was very tight, had to have been 15" or even less. The
> trolleys can manage very tight radius. They are designed to round
> street corners.
> ...


It's going to be a very simple layout; a _very_ squished down oval is the best description. Parallel tracks in the middle, a loop on either end, hence my description as a Dogbone .I do plan on overhead power, but as it's a basically a loop that too will be pretty simple.


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## DonR (Oct 18, 2012)

Since you are using an overhead to power your trolley you could have
a true dog bone and not have to worry about the reverse loop
problem. But you would have to have 2 springable turnouts so
you wouldn't have to 'throw' them.

Don


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