# Cars jumping on curves



## jpmasek (Jun 19, 2014)

I'm new to the hobby and have built a railroad on the side of my house. When my cars go around the curves they have a tendency to ride up on the inside of the rail before turning causing the cars to bounce and sometimes derail. 

Are my curves supposed to be level or banked? Is that what is causing this or am I supposed to oil the inside of the rails on the curves?

jpmasek


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## chuck n (Jan 2, 2008)

What diameter curves are you using? What type of cars, long, short, 2-axle, 4 axle, etc.? We need more information before we can offer much help. The more info the better.

Chuck


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## John J (Dec 29, 2007)

Curves should be level side to side. Could be curves are too sharp for the rolling stock you have. Also could be the gap between the flanges of the wheel are too wide. What rolling stock do you have? Are these freight or passenger cars? What brand. 

JJ


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## jpmasek (Jun 19, 2014)

The Loco is an LGB Mogul and it has no problems. It's the cars. All are Piko and it seems the longer the car the better it works. An ore car I have is particularly bad but it will do it with the Piko American Steam passenger cars. 
The problem curve, of course is the 4 ft but I noticed it on the 6ft. also. All the track is Piko. I did bank the curves but I noticed that over time and a few rains things change and some have flatten out. Also, I just learned about easements. I really did not do that. 
Instead I had to insert a straight piece in to make the loop work in my space. I built on the side of a steep hill on large rock and everything is elevated.


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## Sjoc78 (Jan 25, 2014)

Looks like no one addressed this yet, but don't oil the rails all that will do is make a mess and possibly affect your electrical conductivity. General run of thumb is make the curves as wide as you can and watch your speeds. I know a lot of trains will go faster than they should. Also if you have longer trains around a curve that will also cause problems.


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## Sjoc78 (Jan 25, 2014)

Just saw your update. If you are mentioning diameter and not radius that is also part of the problem, the 4ft diameter starter curves are really crappy for most things including the trains they come with and you will probably eventually burn out the motor on your LGB mogul running it on those curves.


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## jpmasek (Jun 19, 2014)

Yeah, I didn't think oil was the answer. My track is not electrified. I use an Air Wire system with a battery in the tender. Works great. Phoenix Sound Card also.


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## jpmasek (Jun 19, 2014)

Unfortunately it is diameter. I had two of them and changed one to 6 feet. That one works better but I still see it starting to ride up the inside and bouncing. It looks like rebuilding these using easements and I think I could change that 4 ft.to 6 feet but that would be about it. The hill is just too steep.


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## tmejia (Jan 2, 2008)

You might want to try adding some weight to the cars.

Tommy
Rio Gracie


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## chuck n (Jan 2, 2008)

Our usual recommendation is to use the largest curves possible. Starter set curves severely limit what you can run. I'm not surprised that your LGB Mogul runs though the curves. LGB designed almost all of their rolling stock to be able to navigate 4' diameter curves. They may not look great on those curves, but they would go through them. The long term problem is that tight curves add significant wear to rolling stock. Motors and gears on engines are not happy campers on tight curves. Wheels and track will also wear out in the long run as well. It depends on the relative hardness of the wheels and track.

Chuck


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## jpmasek (Jun 19, 2014)

Oh yeah, I forgot to add I swapped out the plastic wheel for Bachmann Metal ones. I don't know if that would make a difference.


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## ewarhol (Mar 3, 2014)

What gauge is Piko? Would something like a Kadee coupler 5 in 1 tool work to check the gauge of the wheels to make sure they're in alignment?


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## SD90WLMT (Feb 16, 2010)

And...."the hill is just tooooo steep"...

Any idea ...How steep...??

Dirk


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## Sjoc78 (Jan 25, 2014)

The metal wheels should improve the performance and tracking. Older Bachmann wheels some times were a little loose and you might need to spread them to an appropriate gauge; they were just press fit together so you could gauge them and fit in a shim if needed with out much effort. I only have a couple cars with their metal wheels so far but they seemed to perform well when I ran them on the display I set up on Sunday. My minimum diameter has been 6ft and most of my trains seem to handle that even on the wonky grade I had to put up with.


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## cocobear1313 (Apr 27, 2012)

How about some pictures or video? I used to run some quite large trains on 5 foot curves. Pictures would be useful in any meaningful dialogue.

Dave


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## Trains (Jan 2, 2008)

Make sure your joints are smooth no gaps, track is level side to side. Any clubs in your area? Maybe someone could help you out..

Don


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## East Broad Top (Dec 29, 2007)

With the Bachmann wheels, make sure there's no "wobble" on the wheel. I've noticed this with Bachmann's wheels. It's just a side-effect from how they're manufactured. In most cases, the wobble is insignificant, but sometimes it can be pretty pronounced. The wobble is caused by the wheel not being square to the axle, thus as it rolls around the effective gauge of the wheel gets wider then narrower than wider... It could be that the "wide" part of the wide may be too much for the tight curves, causing it to roll up and over the rails. 

If you have a set of dial calipers (digital ones work, too) measure the distance between the flanges on the wheel, often called "back-to-back" or "BTB" spacing. The "standard" for large scale is between 1.560" - 1.575". If it measures greater than this at any point, then the wheel is considered too wide. 

You mentioned your curves were banked at one point, but the rains tended to level everything. It's very important--especially on curves as tight as yours--to make sure they're level side to side all the way through the curve. Twists in the track (uneven side-to-side) cause the wheel to rise above the rail, then the flange isn't there to keep the wheels on the track. Think of a 4-legged chair or table on an uneven floor. That's what's happening with the trucks on our rolling stock when it encounters twists in the track.

The rolling stock you're using is designed to navigate 4' diameter (2' radius) curves, so that by itself shouldn't be the problem. I'd investigate the wheels and make sure the track is dead-nuts level from side to side along the length of the curve and see what that does for you.

And welcome to MLS!

Later,

K


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## jpmasek (Jun 19, 2014)

OK, I think this is the real problem and I have to check the wheels on those bad cars cause that could be effecting it also. 

I have been trying to bank them and I got extreme yesterday but ran out of time to finish and run the train through. Now I'm glad I did not finish. Time to go out and make sure the curves are level. 

Also, I think I can fit a 6 foot diameter where that 4 foot is. I have about a two minute video that shows the entire layout. Haven't figured out if or how I can post that so everyone can see what I am doing.

To Don at Trains... I'm from Omaha. Graduated from South High in 1968. 
John


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## Trains (Jan 2, 2008)

6 foot diameter is pretty small! I would go a min of 8 foot diameter if you can.

Don


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## jpmasek (Jun 19, 2014)

Success!!! East Broad Top had it correct. 
I had both problems but I think the biggest was the banked curves. I leveled everything out. Then I checked the wheels. 
One set on the problem ore car had a real wobble. I moved that set to the center and used a different one for the lead. Also, some wheels were too wide and so I pushed everything as tight as they would go. Bingo! 
Everything glides through the curves, even the 4 foot which I still want to make larger. 8ft? That would be great if I could pull it off. Might have to wait till my next house. 
Thanks everyone.


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## chuck n (Jan 2, 2008)

In my opinion there is a big difference in going to a larger diameter curve than the minimal 4' diameter.

My first layout in the Denver area was built into the side of a bank. All I could use was LGB 15000 curves (5' diameter). On that layout I easily ran all my LGB engines and cars. I built a terrace for the layout and had to make a trestle for one of the curves. 










The first three cars are on the trestle, the only way I could make the return curve without even more excavation of the hill.










Upper loop and lower loop. They were connected by a cog line.









The upper level had LGB 16000 curves.

I could not now run the larger Bachmann, USAt, and Accucraft engines and cars that I now have on the lower loop, but in the time period, late 1980s and early 1990s the LGB designed cars and engines worked very well.

If you are limited in space for your curves, you will be limited in the cars and engines that you will be able to run. Run what you can and enjoy.

Chuck


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## dcraig (Jun 23, 2010)

I was told when I first laid track was to add a small amount of super elevation to the curve. This turned out to be very bad advice. I am still having problems with engines and cars jumping where I did not completely get rid of this and the track is not level. Another problem is that periodically some bonehead will step on my track and bend the rails. If the width between the rail is off this will also cause derailing. It does not take much to cause problems. The montra that has been going through these posts that wider is better is very true. Design your railroad with the largest minimum radius that will fit.


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## Dan Pierce (Jan 2, 2008)

You can not bank the curves!!

Track whether straight, curved or switches must be flat side to side or you will get derailments.


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## mgilger (Feb 22, 2008)

Dan,
Super elevated curves are fine, but not for tighter diameter curves. I would limit super elevation to 10 foot diameter, or more. All of mine have maybe 2-4 degree elevation and they have never given me a problem. I'm guessing at the degree as I've never measured mine. 

I agree that switches need to be kept flat, side to side or your asking for trouble. 

Mark
*http://mmg-garden-rr.webs.com/*


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## chuck n (Jan 2, 2008)

Mark, you are fortunate that you don't have any problems with non level track on curves. My layout has only Aristocraft 10' diameter curves. It has been down for 20 or so years, floating on ballast. This past weekend all of a sudden I had a couple of cars that always derailed in the same spot on a curve. All of the other curves were fine. I brought out a level and discovered that the track was not level across the rails. I brought out a trowel and releveled it and the problem went away.

I do not know the angle that Mother Nature put into the roadbed, but that was the problem.

Chuck

Ironically, it was two Aristo 2-bay hoppers that were derailing. All the LGB and USAt cars in the train stayed on the track.


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## Totalwrecker (Feb 26, 2009)

Chuck, the dip that erosion caused is a lot different from the SE that Mark and I allow. You ran on my curves and they all have a natural SE. It's a real long taper and not the same as your recent maintenance issue. 
I passed on backing Mark earlier because of 'the world is flat' mindset. I've bucked the best minds of this forum on this issue, but have also come to realize that I see the flow differently than many of us. 
I free float the track and set the angle by shakes, I allow the rails to set their own rake. I do soften it as much as the give allows. Yeah I say allow because I use sectional track and it's too easy to force it out of true. I push my joints together as tight as I can get them, Aristo Stainless Steel and I torque the little screws as tight as I can using screw driver handled ball wrenches. The whole layout swells and shrinks as one....
For newbies; go flat. As you gain experience, experiment as you desire....
Chuck try loosening one truck on each car, trucks sound stiff if only those strayed.

Happy Rails
John


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## chuck n (Jan 2, 2008)

John, there was a whole 6' section that had tilted and all of the trucks are pretty loose.

Chuck


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## Randy Stone (Jan 2, 2008)

I wholly agree that larger diameter/radius curves are better. But tight CIA/radius has little to do with this problem. The rails are either not level side to side, twisted or kinked. You can put sectional curve track together, then pull one end towards the center of the circle thus tightening the curve, most likely twisting the rails and even kinking the joints. A rolled rail from twisting may be level side to side but be the cause of derails.


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## Totalwrecker (Feb 26, 2009)

chuck n said:


> John, there was a whole 6' section that had tilted and all of the trucks are pretty loose.
> 
> Chuck


Was a thought, I'm glad you resolved your washout! 
John


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## chuck n (Jan 2, 2008)

Thanks John, every layout responds differently. That is why, in my opinion, there are no absolutes in this hobby. Only suggestions. What works for some, may not work for others.

I guess that if there is an absolute, the only one I can think of is the engine needs some form of power. Beyond that everything is open for discussion, not debate.

Chuck


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## SD90WLMT (Feb 16, 2010)

Well there's certainly lots of colorfull discussion in this place!!!

LOL

I'm trying to brake all those peskie railroad rules here....
...just because!!!
...Dirk


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## docwatsonva (Jan 2, 2008)

I have 20ft diameter curves on my outside loop of my layout. My track floats in ballast. On occassions I have run my ABA streamliner train at full speed (~ 24v) and have never had a derailment or tip-over. My track is perfectly flat with no SE. The key to problem-free running is making sure tack is level side-to-side and front-to-back.

Doc


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## mgilger (Feb 22, 2008)

Several things I should say about my comments about flat verses super elevated curves. Everyone's layout is a little different, so what works for one person might not work for others. My layout might not be typical, but what I have found are:

1) All of my cars, except for my heavy weights have extra weights added to bring them to typical running weight of between 3-4 pounds. So add a little weight to your cars. No exceptions. 

2) Super Elevated curves are ok for larger diameter curves. When I first started out in 2005 my curves were 6-8 foot and I would have to say I used to have some problems on some of my curves at that point. Currently all of my curves are 10-24 foot in diameter, but all of mine are hand bent using a rail bender. So they are not out of the box a certain diameter/radius. They were bent to fit a particular area. I have over 1,700 feet of track with dozens of curves ( all super elevated ) and 50+ switches and everything is free floating on #9 gravel roadbed. 

3) All switches should be level side to side. It does not have to be level end to end. 

In a normal operating time frame, 4-6 hours, there are typically no derailments except the ones made by human error. When we have operating sessions, 3-4 times a year, some of the guys make mistakes and derailments happen, especially when there is a head on unexpected meet. That's bad news. For some reason a consist doesn't like coming to an immediate and abrupt crashing halt. We all get a good laugh out of it and once things are put back on the track things take off again.

Anyway, the intent of my post was to dispel the idea that all track has to be level, side to side. Under some conditions level should be the norm, under others it's the exception. 

Regards,
Mark
*http://mmg-garden-rr.webs.com/*


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