Rolling Stock Wheels

[rbryce1]

I would like to convert as many of my wheels from plastic to steel as possible, as the MRR club in my area does not permit plastic wheels on the club track.  I see there are 33" wheels, 34" wheels, 36" wheels and probably more, but I am not really sure of the importance of this or how to determine which wheels I currently have, can use or actually need.  I understand what the 36" means, but not how to identify them in HO scale.  Also, what are needle bearing wheels?  Is it just the axle going to a sharp tip or is there a bearing in there.  Seems awful small to have an actual bearing, but I have been really surprised at some of the things I have seen so far, especially in the mechanism on steam engines, so nothing can be "too small to be made and work"!

All help will be appreciated.

[RAM]

Most freight cars have 33 inch wheels.  Most passenger cars have 36 inch wheels.  Now when you get into the big cars like 100 ton cold hoppers , I think they have 36 inch wheels. 

[rbryce1]

If I just replaced them all with 36" wheels, would I have a coupler height problem, or is the difference to small to worry about?

[Doneldon]

rb-

An interesting question but not a very good idea.

Ignoring specialty cars, freight cars have 33" wheels so their bolsters (the cross members under the floor of the car to which the trucks sort of attach) put the floor at the right height so the draft gear (the box into which the coupler shanks fit) is at the right height so the couplers will line up correctly. The same is true for passenger cars and 36" wheels. Using all 33" wheels would make your passenger cars' couplers too low and using all 36" wheels would make your freight cars' couplers too high. While it's true that this is only 1/29" difference, wrong height couplers are serious problems, particularly if you have any grades on your layout. And deciding that it doesn't truly matter since you plan to never couple freight and passenger cars together isn't a solution, either. Your switch engines will need to be able to move both kinds of cars. An,d you may find that trying to have one roster of road locomotives for freight trains and a separate one for passenger trains isn't very practical. Plus, it just isn't right.

Stocking both 33" and 36" wheels isn't really a hassle. For one thing, most layouts don't have a large number of passenger cars and many of those (if they have lights) are likely to come with metal wheels anyway. So use the right wheels, make sure your couplers are installed perfectly, be careful with your trackwork and you should enjoy reliable operations. And your trains will look right, too.
                                                                                                                                 -- D

[sd24b]

most modern freight cars (100) have 36" wheels.  Some coal hoppers and intermodal wells have 38"  50-70T cars usually have 33" wheels.  Most passenger cars use 36"  You will find metal wheels will improve you locomotive's pulling power.   Phil

[jward]

i have found that most freight cars have 33" wheels. using the larger 36" wheels can cause the wheels to rub against the car floors. it can also interfere with the free pivoting of the trucks as the wheels get hung up on details under the car. and it throws the coupler height off a little bit.

the best advice i can give is to replace the wheels in kind. compare the wheels you are replacing to a 33" wheelset. it should be obvious if they are the same size.

[rbryce1]

If I am understanding this correctly, it is actually the combination of the coupler box AND the wheel height together that is important, as that determines the actual coupler height above the track, which makes sense as they would both together need to provide the common height needed for all types of cars to line up with all types of engines.  I think I will order a card of 33" wheels to start off and compare the different wheels on the cars, as 80% of the cars I have with plastic wheels are freight cars.  This height being so small a difference to the eye, I think I will align two 33" new wheels on a flat surface and put my target wheel in the center of them and place a straight edge over the axles.  if it aligns, they are the same height.  If it wobbles, the center wheel is taller. 

I only have one B & O passenger set of 4 cars with plastic wheels, as the 5 McKinley Explorer cars are all steel wheels for interior lighting.

Yes, I know that Bachmann only makes 4 of the McKinley Explorer cars with lighting, but I have swapped the chassis on a Chena car and the Kenia car to make a lighted Kenia car.  Worked easy & great.  Man, that's one long train!

[ebtnut]

Might I suggest that you consider obtaining a decent caliper to make small measurements?  It's a handy device that will find many uses in the hobby and even around the house.  There are some that actually measure in HO scale feet and inches, which you may find at good hobby shop.  You can also find them at places like Harbor Freight - some with a dial read-out; some with LCD display, and readouts down to .001".  It's a good investment.

[rbryce1]

CRAP ... I feel so stupid ... I actually have 3 of them (2 are digital) and a full set of mic's.  Yes, I agree, your suggestion is far better.

Any info on the bearings?

[ebtnut]

Typically, the needle-point bearings on the axle ends simple ride in the small counter-sunk hole in the back of the truck frame.  Most of the trucks in commercial rolling stock these days are made of Delrin or similar engineering plastic to give good rolling characteristics.  The one thing you have to watch is the the length of the wheel-set axles is NOT standard.  Make sure before you go whole-hog that you check to make sure that the new wheel-sets fit the trucks without binding or falling out. 

[rbryce1]

That's interesting!  I bought a Rivarossi 4-6-4 engine in great shape which I converted o DCC, but the wheels keep falling out of the trucks on the tender when you pick it up.  They always stay in place once it is on the track.  I was thinking the trucks had been separated, but now I wonder if someone replaced them and used the wrong length wheel.

Taking it out and measuring it will tell me what is there now, but does anyone know what size wheel SHOULD be there (33" or 36").  If someone changed all the wheels with the wrong length, they may have installed the wrong diameter as well.  Engine and tender are giving me no problems now except for the tender wheels falling out when you pick it up, and it doesn't do it all the time, about 40-50% of the time.

[electrical whiz kid]

Rivarossi tenders should have scaleld out to 36" dia. wheels; what came with them-the "pizza cutters" (I had one of the oldest models) could have been smaller, giving the illusion of being sized properly.  I converted mine to Reboxx 36" scale wheels.
Rich C.

[richg]

Reboxx and NWSL have different length wheel sets. With all metal, you have a nice shiny thread and very little issue with picking up dirt/dust.
Not many railroad wheels had black wheel threads.
Our club switched many years ago.
Get a couple height gauge.
Get some Kadee red and grey compressed paper washers to fine tune the height of the rolling stock.
Sometimes I shim the coupler with thin styrene to lower the coupler rather than raise the rolling stock. Raising the car "might" cause issues.
This all comes under model railroading.

Rich

[roger]

REeboxx sells a 10-pack of wheels,each with a different axle length so we can really find the appropriate length for the truck we are working with.
Each axle is a different color, with a printed reference code. Makes finding the proper fit a snap!
KD and Proto are one universal length, and work for most cars.
I rebuild/upgrade the old stuff, and even found proper wheel sets for the old Bachmann 28' TOC cars made in the 60-70's.