33" wheelset comparisons

[Cajonpassfan]

There have been at least a couple of threads recently discussing some of the better aftermarket wheelsets, but I've had hard time understanding their subtle differences without access to specific dimensions. I've acquired some of  the new 33" "semi-scale" wheels from FVM/Scale Trains and Eastern Seaboard Models, and compared them to BLMA and Rapido sets I had on hand. I measured their wheel rim diameter (D), diameter at flange (OD), flange depth (FL, diameter at flange minus rim diameter divided by two) as well as the wheel thickness (T), which is much easier to measure than thread width. My digital caliper may or may not be 100% accurate, but it is accurate in terms of relative dimensions. So here's what I get, in inches:

FVM/ST:    D .204, OD .234, Fl .015,  T .057

ESM:         D .208, OD .246, Fl .019,  T .065

BLMA:       D .211, OD .244, Fl .0165, T .064

Rapido:     D .203, OD .251, Fl. 0.24,  T .068

I did not have the FVM/ST "standard" wheels at hand, but believe their thickness is about .070"
The metal Bachmann's, for comparison in two of the photos, scale at 0.84" thick.

The wheel faces vary quite a bit as the photos show. From left FVM/ST, ESM, BLMA, Rapido; the fifth wheel is Bachmann.
The last one is ESM and BLMA, left to right.
I do wish my iPhone was capable of making better closeup photos.
Fun stuff,
Otto K.

[sp org div]

 I think that third image gives the best overview for visual comparison. The others create a bit of distortion compared to my personal view of each product.
For tracking characteristics, surely each holds its own right to being king on any particular railroad while still maintaining the best possible appearance to do so
Once you delve into radius turns under 24” with grades over 2 percent, the reliability factor falls sharply for low profile wheels. Running 50 car trains here with 22-1/2” R @ 2 percent but it has required body mounts for rolling stock to track well sporting those finer wheels in the above photos.
 I am interested to see what you can pull off there Otto considering the tighter and steeper grades on that spectacular layout. You go dawg!

[Cajonpassfan]

A friend tells me that the NEW Intermountain wheelsets are quite nice. I didn't care for their old metal wheels because of their fat and clutzy profile, but if the new version is a contender, I'd look at them again. Can anyone here who has them take a photo and a good caliper and post a pic and measurements in the previously posted format?
Much appreciated, Otto K.

[robert3985]

Thanks Otto for that comparison!  I like the way my FVM wheels look, but...they may not be the most prototypical looking as far as front and back profiles are concerned.

I like the FVM's narrow tread, which is the most visible part since it's bright and shiny.

I think I'll have to do a bit of thinking about this as the ESM wheels look pretty close to what I'm seeing in these prototype photos with the wheel "rim" being just an RCH too wide IMO.

Here are some photos of North American freight car wheels to look at in comparison to your photos of the N-scale wheels...












Cheerio!
Bob Gilmore

[bbussey]

Note in the first photo that the left wheel is newer than the right wheel even though both are weathered evenly.  The tread is thinner on the right wheel and therefore has more mileage on it.

[nkalanaga]

The AAR field manual for 1977 says wheels are condemnable if the flange is more than 1.5 inches above the tread.  They don't give the dimension of a new wheel, but from the looks of the diagrams, that appears to be about one inch.  That would allow 1/2 inch of tread wear.  If worn evenly, that would also thin the rim, but more often "dishes" the tread.

They also give wear limits for rim thickness, but again, no standard for new rims.

[fire5506]

 New rim thickness would depend on if it is a one wear wheel or multiple wear wheel. One wear wheels when taken out for any reason are normally scrapped. Multiple wear wheels can be turned to specs until it become too thin. reconditioned multi wear wheels need a minimum rim thickness of 1" to be able to install in a car.
  Condemning thin rim for 33" wheels is 3/4" and 7/8" for any other wheel. Thin flange limit is 15/16". High flange is 1 1/2". Vertical flange is 1", which I have never seen in 37 years.
  There are other things that can condemn a wheel. There are 75 pages devoted to wheels in the 2017 AAR field manual.

  Richard Webster

The AAR field manual for 1977 says wheels are condemnable if the flange is more than 1.5 inches above the tread.  They don't give the dimension of a new wheel, but from the looks of the diagrams, that appears to be about one inch.  That would allow 1/2 inch of tread wear.  If worn evenly, that would also thin the rim, but more often "dishes" the tread.

They also give wear limits for rim thickness, but again, no standard for new rims.

[nkalanaga]

Fire5506:  Sounds about the same as the 1977 Manual.  Not surprising, as today's wheels have to work on even the oldest track.

So, between multi-wear and single-wear wheels, rim thickness can vary a lot.  Maybe we don't need to worry quite so much about variations in our wheels?

[robert3985]

Fire5506:  Sounds about the same as the 1977 Manual.  Not surprising, as today's wheels have to work on even the oldest track.

So, between multi-wear and single-wear wheels, rim thickness can vary a lot.  Maybe we don't need to worry quite so much about variations in our wheels?

My thoughts exactly.  Kinda like prototype rail being really crooked and bumpy in many cases as compared to our near-perfect track that we strive for.  Which is why, when I laid my Park City Branch Yard at Echo, I deliberately make it crooked, but not bumpy. I had a friend who I was teaching how to hand lay track who was having difficulty getting it "perfect" in that yard, and he was very surprised when I told him that I had forgotten to tell him to deliberately make small crooks when soldering the rails to the PCB ties because the prototype was also crooked.  Perhaps easier to do when hand-laying as opposed to manufactured flex.

Cheerio!
Bob Gilmore

[babbo_enzo]

it's slightly off-topic, but a friend asks: Minitrix freigth car (suppose 33' ) and passegers (suppose 36') which wheels can be mounted?
and what length of axles ?
If anyone knows it's welcome!!
Thanks for any feedback
Cheers
Enzo Fortuna

[bbussey]

it's slightly off-topic, but a friend asks: Minitrix freigth car (suppose 33' ) and passegers (suppose 36') which wheels can be mounted?
and what length of axles ?
If anyone knows it's welcome!!
Thanks for any feedback
Cheers
Enzo Fortuna

You have to measure the axle length of the existing wheelsets to determine that.

[peteski]

it's slightly off-topic, but a friend asks: Minitrix freigth car (suppose 33' ) and passegers (suppose 36') which wheels can be mounted?
and what length of axles ?
If anyone knows it's welcome!!
Thanks for any feedback
Cheers
Enzo Fortuna

Are you asking about American or European prototype models? 

[babbo_enzo]

Are you asking about American or European prototype models?

Hi Petesky, but ....I don't know, sorry ....
Given the guy is a Fremo member I "suppose" it refer to European cars...
I have also already suggest to exact mesurement of existing axes with a digital calipher ... just waiting some news from him.

[babbo_enzo]

Happy Eastern to all, friends....
Here an "update" from my Fremo friend, with mesurement !!
Axes length = 0,596" !!
Wheels diameter = 38,4
Never see these figures!
Cheers

[peteski]

Happy Eastern to all, friends....
Here an "update" from my Fremo friend, with mesurement !!
Axes length = 0,596" !!
Wheels diameter = 38,4
Never see these figures!
Cheers

That is 15.14mm axle. That sounds like a typical wheel from European prototype model, especially with a 0.596" axle.  1:1 wheels are around 1m diameter (39").  So, it would be difficult to find equivalent wheelset using American prototype wheels.  In what model is your friend looking to replace the wheels?

DM-Toys sells a range of European-specs N scale wheelsets.  Those might work for your friend, but unfortunately they have rather deep flanges (typical of most European N scale).

Here are those wheels for Minitrix, but only scale 35" (or 0.220" or 5.6mm):
https://www.dm-toys.de/en/product-details/N-Train_171.05.html