I have several Bachmann Spectrum steam loco’s in my roster. 4-8-2 Heavy Mountain, 4-8-4 J class in particular that I have the same problem with. The front truck assembly seems to be very light for lack of a better term on the rails. I can hardly make a pass on my pike without derailments. Now before everyone says it’s my track work which I will admit is not the best in the world but I am improving my skills greatly as I go along. I have 10 IHC big steam loco’s that make the circuit without a hitch. Even my 2-8-8-2 Mallet and my (new generation and old generation Rivarossi Big Boy’s and my Allegheny all make the circuit with out a single problem.
It was suggested to me by a friend that I remove the front truck assembly and reverse the position of the spring. Well I tried that but there is no spring. It fits in to a pocket and the wheels are held into the assembly the same way.
Has anyone else had this same problem and if so what did you do to fix it? These are all great looking engines with fantastic details but they belong on my pike not on the shelf. Any suggestions would be greatly appreciated.
I have the Heavy Mountain, and have never had a problem such as you describe. And my trackwork is not the best in the world, either. You might try adding weight to the pilot truck. If you can find some sheet lead, such as was used for flashing on roofs "in the day’, a sliver above each axle might help. Also, make sure the truck pivots freely, both in the pocket where it mounts to the frame, and at the pivot in the center of the truck. There should be a fairly wide range of motion there. Check the wheelsets to make sure they are turning freely. Some LaBelle #108 in the axle slots will help.
Do the locomotives derail consistently at the same spot on the layout? If so, look hard at that spot in the track. You may have a kink, misaligned rail joiner, etc. It can help to run the loco very slowly past that spot while watching very closely. If you can spot the exact point where the wheels begin to derail, and stop the loco immediately, you may, by carefully observing the positions of wheels in relation to the loco and the track, spot where the problem is, and thus figure out how to fix it.
What is your minimum curve radius? While the IHC and Rivarossi engines are all made to go around 18-inch radius curves, the Spectrum 8-coupled locos are limited to 22" radius minimum, and are not happy on less than 24".
Thanks for the reply, no there doesn’t seem to be any one place in particular but actually several spot. I do run minimum 18" on an inside loop in one particular spot but the rest of the pike is running 22" and a 26" curve in one spot. I am leaning towards the min. radius problem.
I had thought about the weight thing too and will try using around .25oz of weight. The sheet lead is a good idea. I’ll try it maybe tonight and let you know how it works.
The track work although it not be the best is sufficient enough for everything else in my roster some 75 engines so all but the Spectrum Steam have zero problems. I even run a PA1 A-B-B-A all powered Proto 2000 set up that pulls 75 cars with out even the slighted hesitation or flicker of a track problem. I am currently building several new modules to be used in my new set up once the new addition we’re putting on is completed. I think I’ll go with 28"-30" min. curves being as I’ll have plenty of room.
Thanks again for your advice, this board seems to Be the best resourse for information I have found. Appreciate it.
I had the Class J and I did have the same problem for a while. I found that the front truck was too rigid and would lift off the tracks if the loco tilted too much or started going down a hill. I solved this by removing some material from around the front of the chassis where the truck pivots (the plastic piece that holds the rest of the wheels in place) I also did not tighten the front screw very tight to allow the truck to drop when needed. I had more trouble with the tender. Again the tender was too rigid and if the additude of the loco was too drastic it would lift the tender and that would usually derail it when it was set back down.
My heavy Mountain loco likes to derail alot but not on the front truck I have problems with the drivers. I cant seem to figure it all out.
4-wheel lead trucks on some steamers seem to have a problem with balance. Generally, if the lead truck is attached to the cylinders with a ‘through-screw’ and spring (as on most brass locos), the weight is distributed ‘flat’ to the trucks by the tension of the spring. I’ve noticed that the Bachmann 4-8-2’s are ‘free-floating’ and connected to the frame by a rear screw. Though I’ve not had derailment problems with mine, I can see where this might be a problem, since the weight of the tension seems to be concentrated on the back set of wheels, simply by the attachment, and not evenly distributed through the truck. My advice would be to use a small, flat piece of lead weight over the front wheel of the truck and see if this does not improve the tracking. It should be enough to distribute the weight of the truck more evenly. Also check the wheel guages of the leading truck.
One thing–even though manufacturers might tell you that the locomotive will negotiate an 18" or 22" radius–you have to remember that a 4-8-2 or 4-8-4 is a LARGE wheel-based non-articulated locomotive and cannot comfortably traverse smaller radiii that are comfortable for a 2-wheel trucked steamer such as a 2-8-0, 2-8-2 or even some 2-8-4’s. Those 4-wheel lead trucks need some room to ‘breathe’. Myself, I’d feel far more comfortable running them on a minimum 24" radius.
I only mention this because it happened to me…make sure the apron (connecting the locomotive cab and tender for the crew) isn’t hooking up on the tender. It’s surprisingly easy for it to slip down when lifting/carrying the engine, and it can cause the front of the engine to lift up and affect tracking of the pilot truck.