This page will primarily benefit those of you that currently use plastic wheels but are contemplating a switch to metal wheels. I will relate my experience with the conversion to metal wheels in the hopes that you suffer less confusion than I did.
I have used after market metal wheels from Gary Raymond, Dean Lowe, and San-Val. I've also used original equipment metal wheels from Bachmann and AristoCraft. For any manufacturer that I've left out, and there are several, its only because I have no direct experience with their product.
There are several types of ball bearing wheels available. I've never tried one, but if I can relate the experiences of others, the rolling resistance improvement for a wheel without power pickups is not sufficiently improved to justify the significantly increased cost. For wheels that do pick up power, a metal wheel set with integrated power pickups has MUCH less rolling resistance than wheels with brushes.
All things considered, metal wheels work better than plastic in most instances. They do, however, represent a considerable expense. If you do decide to convert, consider doing it all at once. You can strike a MUCH better deal if you buy in a quantity of 200 axles or more. You can sometimes swing a deal and get them for down to $2/axle in a sufficient quantity.
In the following trade table, I treat all kinds of metal wheels the same. There are some differences between the various metal wheels as discussed later in this page, but those differences are small in comparison to the difference from plastic wheels.
|Rolling Resistance||Higher||Lower. Metal is harder and deforms less. Test after test of metal wheels vs. plastic show that metal rolls better than plastic. This also translates into longer trains on level track.|
|Weight||Lower, allows more cars to be pulled on grades||Higher, depending on the grade, lower rolling resistance is more than offset by higher weight so that fewer cars can be pulled on steeper grades. Crossover point appears to be at less than 1% grades|
|Sound||Less rolling noise, dulled "clickity-clack"||More pronounced rolling noise, especially at rail joints. Can be either an advantage or disadvantage depending on what you like|
|Track Contamination||Can leave a layer of plastic on the rails, increased problems with track cleaning||Leaves virtually no contamination on the rails.|
|Wheel Ribs||Can be easily ribbed on the backside during manufacturing||Most wheels made on a screw machine so that ribbing is impossible|
|Power Pickup||Plastic is an insulator, cannot be used for power pickup||Can be used for power pickup, but brushes increase drag. Some ball bearing wheels (expensive) have integrated power pickups and add virtually no drag|
|Tracking||Worse||Higher weight improves tracking, especially on lighter cars. Weight is carried below the bearings so that bearing friction is not increased like adding weight to the car body.|
|Color||Usually black, not too visually obtrusive||Often supplied in unrealistic colors, but they usually take paint well|
Under some conditions, plastic wheels will provide better service than metal wheels, and the price is certainly right. If you run battery power so that plastic crud on the track is not a problem, and you run short trains so that the lower rolling resistance of metal wheels provides no advantage and you have steep grades such that the extra weight of metal wheels adds significant loads, then you might be better off with plastic wheels. In most other cases, metal is the way to go.
There are two common flange profiles used in large scale wheels, the original LGB profile and "finescale" profiles. The difference can be significant.
The standard large scale wheel has a fairly wide tread, a deep flange and an abrupt transition from the tread to the flange. The tread diameter is usually about 1.2" and the flange height is typically 0.125 inch. This wheel profile was developed to be fairly tolerant of track gauge variation and to allow the wheels to track reliably on tight radius track while being pushed and pulled around by truck mounted couplers. All in all, this profile works pretty well.
Some manufacturers add a radiused transition between the tread and the flange. This is consistent with prototype wheels. The radius tends to keep the wheels centered and helps prevent the flange from bearing directly on the rail which increases rolling resistance. These manufacturers claim reduced rolling resistance and I have no data to dispute the claim, but I suspect that the difference is pretty minor.
Gary Raymond makes his wheels with a smaller flange which is closer to prototypical dimensions. These wheels are visually more appealing than the standard wheels, but do suffer from tracking problems under worst case conditions, like backing long trains with truck mounted knuckle couplers through tight radius turnouts. For users with code 197 or code 215 rail, these smaller flanges may be required to keep the flanges from bouncing on spike heads, especially ones that have loosened a little. On cars with body mounted couplers, many of the tracking problems due to the smaller flanges will evaporate. Some "finescale" wheels have a narrower tread than standard wheels and will literally drop between the rails on track that is only slightly over gauge, such as in LGB 1600 turnouts, see LGB 1600 Turnout Tips.
All metal wheels are not made from the same stuff and there are performance differences between the materials and their coatings.
|Steel||Extreme resistance to wear. Machining process tends to produce accurate wheels||Rusts without coatings. Can be attracted to Kadee uncoupler magnets and interfere with automatic uncoupling|
|Stainless Steel||Extreme resistance to wear. Machining process tends to produce accurate wheels. No coatings required||Tends to be expensive. Can still pit under very high current loads. Brass rail materials can become embedded in the wheel during arcing, corrode in place and still cause pickup problems.|
|Brass||Good resistance to wear, easier to machine so can be less expensive, non magnetic so not affected by Kadee magnets. Machining process tends to produce accurate wheels||Unrealistic color, cries out for coatings. Unplated brass tends to pit, tarnish and corrode when used to pick up power, requires lots of wheel cleaning.|
|Casting alloy||Can be cheaper than CNC machined wheels||Not as heavy as brass or steel, sometimes rougher treads and flanges. Not always perfectly round. Copper casting alloys have the same problems as brass when used in power pickup applications.|
|Uncoated||Less expensive||Steel will rust, brass looks wrong|
|Anodization||Typically black, marginally acceptable color, most coatings still electrically conductive||Still needs painting to look good|
|Nickel Plating||Low cost, protects steel from rusting and brass from corrosion||Color completely wrong, requires painting|
The following table is my interpretation of the features of the wheels that I have used. I believe that the information is accurate, but there is no guarantee. Again, there are other manufacturers of quality metal wheels, I just don't have any direct experience with them.
|Mfgr||Wheel Material||Wheel Coatings||Profile||Notes|
|Gary Raymond||Steel||Uncoated, anodized or Ni plated||Finescale or Semi-Finescale profiles||Available in a large range of sizes|
|Dean Lowe||Steel||Anodized||Radiused profile between tread and flange with a standard flange depth||Available in 4 sizes|
|San-Val||Brass||Ni Plated||Standard profile||Available in only one size, but fits most cars. Tread is 1.125" diameter, somewhat smaller than many plastic wheels.|
|Aristo||Brass||Unplated, Ni plated, or anodized||Standard||Available in only one size but fits most cars. Typical tread diameter is 1.16"|
|Bachmann||Cast||Anodized||Small radius between tread and flange||Available in only one size but fits most cars. Tread is 1.21" diameter. Underguage but can be easily adjusted, insulators on wheel back are very narrow and can short to axle if left out of doors, can be prevented with a little silicon sealer. Blackening wears off after extended running leaving a shiny tread and flange.|
I do not intend to endorse any one kind of wheel over another, you should make your own evaluation and pick your wheel based on a cost/benefit trade. All of the wheels that I have used have provided good service and were of good quality. I don't even run new cars with plastic wheels, I change them out before the car ever hits the track.
I prefer to paint my wheels to get a realistic color. I've painted perhaps half my wheels at this point. I prefer Nickel plated wheels so that the tread remains shiny like a prototype wheel but is still protected from rust or corrosion. Prototype wheels are never painted as paint tends to hide cracks, so the wheels rust and then get coated with burnt oil, grease and dirt. I paint both sides Roof Brown with an airbrush and it goes really quickly by masking the tread and flange with a 1-1/8" x 1/8" rubber o-ring. Solid Roof Brown looks like old rust and the fact that the color is uniform doesn't show up when the wheel is under a car and behind a truck. For a display model, more detailed painting is probably in order. If the wheel is to be used with power pickups, don't paint the back side.
Don't paint the tread as the paint will wear off and foul the track. If you do get paint on the tread or flange, a Q-tip soaked in lacquer thinner will take it right off.
Metal wheels that are used for power pickup will require cleaning at times. Some wheel materials, especially brass and copper alloys, will pit when they arc on dirty track. Long exposure to the weather can cause some materials and coatings to corrode or rust, this must be cleaned off for the wheels to contact the track reliably. Metal wheels NOT used for power pickup don't need much attention at all.
Metal wheels are usually cleaned by abrasion. A normal green Scotch Brite pad will easily deal with the light stuff. The rust colored Scotch Brite pad is useful for heavier crud. The wheels must be turned by hand to allow the whole tread to be cleaned. When the going gets tougher, a Brite Boy cleaning block can work off the heaviest crud, but this is a slow process.
A faster and very effective technique is to use a Dremel motor tool and a brass wire brush. The spinning brush will also spin the wheels so that you'll need to apply the brakes with a finger to allow the brush to spin against a wheel, but the wheel can be easily rotated to clean the whole tread. On geared loco wheels, a Kadee wheel brush is effective to apply power and scrape off some of the crud from the rotating wheels. Then the Dremel tool can be applied to the rotating wheel to clean it quickly and effectively.
This page has been accessed times since 17 Dec 97.
© 1997-2007 George Schreyer
Created Nov 24, 1997
Last Updated September 9, 2007