We have found "out of round" wheels caused by a build-up of "crud" on one part of the circumference of the wheel tread.
Talking about "best truck," and "best wheelset" doesn't answer the performance question. As Sheldon points out, finding the proper truck/wheelset combination is a successful approach.
At one time, Kadee axle tips had a bit of a curve to them, so the taper from the wheel face to the axle tip was a curved line, not straight. That's fine in a matched truck but not otherwise.
The NMRA has published standards and practices for wheels and trucks, but they have to be taken as a system.
riogrande5761Ok, thanks for the info on Kadee - so they are "molded zinc". I wonder how that compares with say machined wheels.
It is a very rare occurrence, but "out of round" wheels have been known to cause derailment issues. It has happened to me. I no longer have the wheels as they were disposed of so they would not be accidentally put back in service.
The question is, would these wheels likely be zinc or machined metal? I wish I had kept them so I could have a look.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
Some years ago, I was at a local train show. One of the club modular layouts had a whole string of old-style auto racks, the old Athearn open-sided ones as I recall. The cars were beautifully filled with shiney new die-cast autos.
It looked great, but the cars had sprung metal trucks. The shear weight of all those die-cast autos bottomed out the springs, and the total weight of the train exceeded the pulling capacity of the power consist, even on the flat layout.
The next show, I think the die-cast autos had been replaced by lightweight plastic models.
It takes an iron man to play with a toy iron horse.
riogrande5761 Doughless So what is it that produces the "free rolling" ability, the metal wheels or the metal axles? I would think the question should be "Metal Axles vs Plastic Axles"? Not sure if the wheel itself is more important than the axle. For what it's worth, I will recount a story of an experiment an old model train friend did years ago. He had a long train of around 30 Intermoutain covered hoppers - which were from the days that they came with plastic wheels. He replaced all those cars with Kadee wheels, as was a common practice back in the early 1990's. He noticed the long train had a lot of drag on it As an experiment, he replaced all the Kadee wheelsets wtih Jaybee. The long train was much free'er rolling after that. The Kadee wheels have a plastic axle don't they? The Jaybee have metal axles.
Doughless So what is it that produces the "free rolling" ability, the metal wheels or the metal axles? I would think the question should be "Metal Axles vs Plastic Axles"? Not sure if the wheel itself is more important than the axle.
So what is it that produces the "free rolling" ability, the metal wheels or the metal axles? I would think the question should be "Metal Axles vs Plastic Axles"?
Not sure if the wheel itself is more important than the axle.
For what it's worth, I will recount a story of an experiment an old model train friend did years ago. He had a long train of around 30 Intermoutain covered hoppers - which were from the days that they came with plastic wheels. He replaced all those cars with Kadee wheels, as was a common practice back in the early 1990's. He noticed the long train had a lot of drag on it
As an experiment, he replaced all the Kadee wheelsets wtih Jaybee. The long train was much free'er rolling after that.
The Kadee wheels have a plastic axle don't they? The Jaybee have metal axles.
Interesting story. I dont know about Kaydee or Jaybee. If I ever buy another car with plastic wheels, like a BB, early Walthers, etc, and feel the need to change out to metal wheels, my preferred make is Intermountain with their metal axles.
I have modern made rolling stock with OEM metal wheels. Very free rolling. But compared to my older BB stock from the 80s and 90s, they are really about the same. The BB have metal axles with plastic wheels.
As Shledon pointed out, most of the friction is between the axle cone and the truck journal. The difference might matter with 50 car trans going up a grade, but I don't see where the wheel material would matter a whole lot. I actually prefer the relative quiet of the smooth engineered plastic wheels on metal axles over the noisier metal wheels.
- Douglas
Rio Grande. The Action Road - Focus 1977-1983
Both.
Lets consider the wheel first. a smooth, hard precision wheel is going to have less friction as it rolls on a metal rail. A softer (like plastic) or rougher (like cast metal) wheel will have greater friction. This will matter most on sharp model curves where the wheel must "slide" at least a little.
Axles - there are several factors here, but most have to do with fit of the axle into the journel. Contrary to what many think, the axle does not ride on its tip. Rather the top of the axle cone rides in the top of the journel cone. The smaller that contact area, and the more precision the surfaces, the less friction there will be.
If it is metal to metal, some oil or other lubricant helps.
NMRA Recommended Practices call for 50 degree axle points and 60 degree journals to insure minimal contact. And call for journal positions to be .003" longer than the axles to insure the axle rides in the top of the axle cone, but with minimal side play.
The NMRA recommends axles of .063" diameter outside the wheel face. Yet many axles in the industry are much larger than this. This can prevent the cone from riding properly in some side frames.
The classic axle turner used to "tune up" plastic trucks simply does what an injection mold cannot, make the inside ofthe journel a reasonably precision surface.
Some years back I did a lot of testing regarding free rolling trucks. I tested many brands of wheel sets in many brands of plastic sideframes. I also tested various wheelsets in various brands of older traditional metal sprung trucks, as well as several brands of plastic sprung trucks.
While I was able to get very good performance from a number of combinations, the consistant winner was what I use mostly today, Kadee sprung metal trucks with Intermountain code 110 wheelsets.
The truck journels are checked for burrs with an exacto knife, given a very small drop of light oil, and the Intermontain wheelsets are installed.
Testing showed that this combination reduced rolling resistance of the Kadee truck by 30% or more, when compared to the stock Kadee truck, allowing locomotive to pull 25% to 35% more cars.
Other setups with plastic trucks came close. But I found that lighter cars in particular benefited from the higher mass of the Kadee truck and the Intermountain wheels and out rolled otherwise identical cars with plastic trucks every time.
Additionally, in my 46 years in the hobby, I feel that one of the reasons I have nearly derailment free operation, even with 40, 50 and even 100 car trains is the use of sprung/equalized trucks. Keeping all the wheels on the rail, and keeping the weight evenly loaded, makes the trucks, and thereby the cars, track better.
So my first choice is a good metal sprung truck with a correctly fitted machined metal wheel and axle.
Back in the day, Central Valley sprung metal trucks where considered the best of the best in HO trucks. I still have more than a few running on my layout. They are admittedly not as free rolling as my Kadee/Intermountain setup, but they too roll well and track exceptionally well when properly tuned and lubed.
One last point - lubrication. Before anyone suggests this is a bad idea, in all my years in the hobby I have always lubed metal axles in metal trucks. It has never caused any issues with dirt, gunk, or oil deposits. Less is more........
Sheldon
Some years back Jay-bee used to be very popular - anyone know what happened to them?
Right http://jbwheelsets.com/here
Ok, thanks for the info on Kadee - so they are "molded zinc".
I wonder how that compares with say machined wheels.
Here is how, for example, ExactRail describes theirs:
"precision CNC machined metal wheel sets and axles"
Like Mobilman44, I've been using Intermoutain wheelsets, most of them from bulk packs, for replacement wheelsets. I am preferring wheel sets with metail axles vs. plastic.
There are lots of good metal axle choices these days - ExactRail, IMRC, Reboxx, Walthers Proto.
riogrande5761 That sounds about right. My understanding has been that Kadee wheels were/are sintered zinc.
That sounds about right. My understanding has been that Kadee wheels were/are sintered zinc.
Here is Kadee's tech advisor Sam Clarke's reply about sintered wheels.
I've used Intermountain (best to buy in bulk) for ten years, and they have proven to be totally satisfactory. There may be others that are comparable, but you will certainly be happy using IMs.
ENJOY !
Mobilman44
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
I'm going to have to agree with maxman, it's for height reasons.
maxmanI believe that it is not so much to increase space as it is to reduce the car height.
Yes, but ... the purpose is still to fit the most usable space within the loading gage. If I remember correctly there can be a matter of inches to spare in getting three levels of some vehicle types within the modern all-enclosed construction, and that is what the smaller wheel sets enable.
ATLANTIC CENTRAL Graham Line the former P2K wheelsets, and Kadee, have plastic axles that can be installed in all-metal trucks without causing a short. Don't know about the current production Walthers Proto wheelsets. Never understood this thinking. I have been using/runnng metal wheel/axle wheelsets with one wheel insulated in metal sprung trucks for nearly 5 decades without any problems. At one time, metal sprung trucks with metal wheels and axles were the industry wide standard. Today I still replace the wheelsets in Kadee sprung metal trucks with Intermountain wheel sets. nearly 800 cars worth. Sheldon
Graham Line the former P2K wheelsets, and Kadee, have plastic axles that can be installed in all-metal trucks without causing a short. Don't know about the current production Walthers Proto wheelsets.
the former P2K wheelsets, and Kadee, have plastic axles that can be installed in all-metal trucks without causing a short. Don't know about the current production Walthers Proto wheelsets.
Never understood this thinking. I have been using/runnng metal wheel/axle wheelsets with one wheel insulated in metal sprung trucks for nearly 5 decades without any problems.
At one time, metal sprung trucks with metal wheels and axles were the industry wide standard.
Today I still replace the wheelsets in Kadee sprung metal trucks with Intermountain wheel sets. nearly 800 cars worth.
It's because some people can't be bothered to check the wheelsets to make sure they have the insulated wheel on the same side in all positions. Granted, on modern wheelsets it's much harder to spot the insulation, if it's at the rim instead of at the axle. Having the wheelsets flipped in a metal truck will, of course, be an instant short. But if everything was fine until you put the new car on the track, there's a 99.9999999% chance the problem is in the new car and not with the wiring or anything else on the layout that didn't change.
Plastic axles of course, you can put them in any old way and they will always work and never short.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
OvermodYou have probably observed that some autoracks have decidedly tiny wheels, again to maximize usable space.
I believe that it is not so much to increase space as it is to reduce the car height.
RailfanGXYWhile I wouldn't see a need to decrease that size for freight cars, could lightweight passenger cars possible have smaller wheels? Like the Talgos or possibly the Pennsy's experimental Keystone cars? Smaller wheels could eliminate the split-level complaint (or at least reduce it)
There is a tradeoff: smaller wheelsets weigh less, but rotate faster, and hence are more prone to damage and wear at higher speeds; the amount of weight a wheel can safely carry without damage is also less for smaller wheels (which is a reason the inner articulated trucks in double-stack well car sets have larger-diameter wheels).
The Europeans are somewhat famous for using extremely small wheels for some of the 'ferry trains' in Alpine tunnels -- some of these use multiple axles for weight-bearing with wheels in the 16" range. There are sites online that describe these. You have probably observed that some autoracks have decidedly tiny wheels, again to maximize usable space.
Some years ago, I started replacing plastic wheels with metal, mostly to reduce rolling resistance. I still have old rolling stock from the 1950s and 60s, mostly Tyco/Mantua and Athearn, so they were due for an upgrade. I had a lot of them, so I went with Intermountain because they offered the best bulk price. I've been very happy with the results. The ancient Tyco trucks had metal frames but plastic wheels, and it was not possible to swap wheelsets. For those and other trucks that were in bad shape, I got Tichy trucks. They fit the Intermountain wheelsets perfectly.
I've made it standard procedure to cover the bearing holes and spray each new truck with rust or brown primer, then give them some weathering with black or rust powder, and finally a sealing coat of clear Krylon spray paint. I apply the Truck Tuner to each before installing the wheels.
I have to use tufts of tall grass between the ties on some of my stub tracks to keep cars from rolling away. With the old trucks and wheels, the cars would stay put. I used to worry about pulling strings of cars off my car float, but now I can pull 6 cars plus the 3 idler flats with my Bachmann 0-6-0 tank engine.
I had hoped to avoid replacing a lot of trucks, but since I found the Tichy replacements it's no problem. I had those old Tycos plus some metal Athearns with real springs. Replacing those relics has given me more reliable performance. The new trucks don't derail, either, and the Delrin bearings are smooth as silk.
So that's the standard wheel size. While I wouldn't see a read to decrease that size for freight cars, could lightweight passenger cars possible have smaller wheels? Like the Talgos or possibly the Pennsy's experimental Keystone cars? Smaller wheels could eliminate the split-level complaint (or at least reduce it)
riogrande5761 mvlandsw I emailed Sam at Kadee. He said that their wheels are made of pure zinc, the same metal used in their couplers. Mark Well, the couplers aren't rolling on nickle silver rail so the material the couplers are made from may (or may not be) the best for wheels. Your next assignement is to email Intermountain, ExactRail and Walthers and find out what their wheels are made of.
mvlandsw I emailed Sam at Kadee. He said that their wheels are made of pure zinc, the same metal used in their couplers. Mark
I emailed Sam at Kadee. He said that their wheels are made of pure zinc, the same metal used in their couplers.
Mark
Well, the couplers aren't rolling on nickle silver rail so the material the couplers are made from may (or may not be) the best for wheels.
Your next assignement is to email Intermountain, ExactRail and Walthers and find out what their wheels are made of.
I do believe Intermountain wheels are nickel plated brass.
SeeYou190 I guess if you just want to watch double headed steamers pull freights in circles all day, well, then that 20-30 seconds might be a positive worth pursuing.
I guess if you just want to watch double headed steamers pull freights in circles all day, well, then that 20-30 seconds might be a positive worth pursuing.
Well, I switch cars and I don't have a trouble with "runaways", but once I started installing Intermountain wheels in my Kadee trucks (with a drop of oil in each journal), the pulling ability of my locos increased by 30%.
I like to run long trains, 35, 40, 50 cars and more. And pull them up 1.5% and 2% grades (yes I'm a grade snob too, no 3.5% grades on my layout). So even with double headed steam, reasonably free rolling trucks are a must.
SeeYou190 I guess we can talk about how much rolling resistance is perfect, but it is like those people who brag about going from tie to tie in 30 seconds or more. Who cares? What is the difference is free wheeling for 11 seconds or 20 seconds? It does not matter. Unless your track is 100% level, you might want some rolling resistance. -Kevin
I guess we can talk about how much rolling resistance is perfect, but it is like those people who brag about going from tie to tie in 30 seconds or more. Who cares? What is the difference is free wheeling for 11 seconds or 20 seconds? It does not matter.
Unless your track is 100% level, you might want some rolling resistance.
-Kevin
It's important if you're going to run 40-50 car trains up a 1.5% grade, possibly out of staging.
My Athearn BB cars with plastic wheels on metal axles inside engineered plastic trucks rolled 20 feet down a less than 1% grade. I guess there may have been a few days in my 40 years in the hobby where I might have wanted more free rolling.
And Proto metal wheelsets have plastic axles. Go figure.
Carolina NorthernSeveral things shocked me. One of the big ones was how bad the rolling abiliities of the wheelsets in HO were. The trucks and wheels in the famous blue boxes need a lot of help to get to N Scale standards.
.
Micro-Trains wheels and trucks were all plastic back when I was in N scale, and they rolled like a dream, and never derailed. I know what you mean.
That is why I only use Kadee trucks in HO. I can say pretty much the same thing... they never derail. They are always in gauge out of the box, and they track like they are guided by laser.
For me, someone who fully weights their freight cars, runs cars back and forth, makes trains and disassembles trains, and puts cars at industries, Kadee is perfect.
Living the dream.
doctorwayne While I have quite a few cars with metal wheels, I'm not a great fan of them. They make a lot more noise than plastic ones, and those shiny treads really draw attention to the overly-wide wheels.I will admit that the current offerings of trucks with metal wheels (Tangent, Tahoe, etc.) do roll better than many of the older cars with plastic wheelsets, but, in my opinion, that's due totally to a better-matched interface between the truck sideframes and the axle ends. Mis-matching wheelsets to the trucks you have may yield disappointing operational results. Wayne
While I have quite a few cars with metal wheels, I'm not a great fan of them. They make a lot more noise than plastic ones, and those shiny treads really draw attention to the overly-wide wheels.I will admit that the current offerings of trucks with metal wheels (Tangent, Tahoe, etc.) do roll better than many of the older cars with plastic wheelsets, but, in my opinion, that's due totally to a better-matched interface between the truck sideframes and the axle ends. Mis-matching wheelsets to the trucks you have may yield disappointing operational results.
Wayne
I'm with you here. Athearn blue box trucks with plastic wheels were free rolling enough. And after proper weathering, look the same as metal. I agree with all of the other reasons you mentioned.
I'm a modern era modeler, and most of my cars require 36 inch wheels. If I could find 36 inch plastic wheelsets (Athearn made them for a while), I'd swap out the factory metal ones for plastic.
well for the most part, most rolling stock (but not all) used 33" wheels. Passenger cars using 36"
A lot of people love intermountain wheels. I use Walthers myself.Ribbed back versus smooth back on freight is a personal choice. But I believe ribbed backs were phased out due to safety reasons IIRC. They were more prone to crack and fail. So modern rolling stock won't have them.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!