What Kind Of Rolling-Stock Uses 34.5" Wheel-Sets?

[pmpexpress]

Just noticed that Intermountain sells 34.5" wheel-sets along with the customary 33" and 36" versions.

What kind of N-Scale rolling-stock uses 34.5" wheel-sets?

[learmoia]

Intermodal?

Or HOn3?

[Tom L]

Are they the ones advertised as MT replacements? I bought some when they first came out and noticed they were larger diameter than FVM. They didn’t advertise the larger size then, that I noticed, so I assumed they were 33” when I bought them. I used them on some express boxcars that run with passenger equipment and have express trucks that kind of hide the size difference. I found it to be quite noticeable on regular freight cars/trucks.

Kind of put me off IM wheels. Can’t get imagine why they did that,’but at least they are telling people what size they are now.

Tom L
Wellington CO

[pmpexpress]

Are they the ones advertised as MT replacements? I bought some when they first came out and noticed they were larger diameter than FVM. They didn’t advertise the larger size then, that I noticed, so I assumed they were 33” when I bought them. I used them on some express boxcars that run with passenger equipment and have express trucks that kind of hide the size difference. I found it to be quite noticeable on regular freight cars/trucks.

Kind of put me off IM wheels. Can’t get imagine why they did that,’but at least they are telling people what size they are now.

Tom L
Wellington CO

Yes Tom.

Those are the ones that I am referring to.

The only version of their wheel-sets that are listed as having an axle length of 0.537", for use with Micro-Trains® trucks, Intermountain now lists the 34.5" wheels as being offered as stock number 60052 (34.5" Brass Insulated Wheel-sets for Micro-Trains® Trucks Axle Length: 0.537") and stock number 60072 (34.5" High Detail Brass Insulated Wheel-sets for Micro-Trains® Trucks Axle Length: 0.537").

Although I am familiar with the Intermountain standard brass insulated wheel-sets, I have not yet come across any of the firm's "high detail" versions.

While the factory supplied wheels are chemically blackened metal, was kind of thinking along the same lines as learmoia, in that the mid-sized 34.5" diameter might be used on the Deluxe/Intermountain produced Maxi-IV car sets.

Could not find any prototype information regarding such a wheel size being used on North American railway rolling-stock.

[nkalanaga]

I found a car that could use them, but have no idea why anyone would need them.  The original (late 60s) Sekisui/ConCor freight car trucks have wheels very close to 34.5 inches.  They're smaller than 36, and larger than 33, but with my ruler I can't tell if they're 34.5 or 35 inches.

The original wheels work fine, even on code 40 flextrak, I have no idea what the axle length is, and I doubt that there are enough of these cars still in use to justify tooling new wheels for them

[sd45elect2000]

Many interurbans and electrics used 34 1/2 wheels (like the North Shore Line) as well as some suburban coaches.


Randy

[BAZ-man]

Dang metric/inch conversion
Or someone measured the smaller outermost of a 36" wheel taper ?
Or, used a kids plastic ruler ?

[cv_acr]

34.5" isn't a real wheel size (although a 36" wheel might wear down...) but given the explicit "for MicroTrains" trucks included in the advertising it might be to match a funky out of scale wheel size from MT and keep the couplers/ride height the same.

Although it seems the different would be pretty slight in N scale.

[nkalanaga]

Chris: It would.  The difference in ride height would be 0.75 scale inches - hardly measurable.  The ride height difference between 33 and 36 inch wheels is only 1.5 scale inches, which is within the AAR's allowable height range for couplers.  Most cars can change that much between loaded and empty.

BAZ-man: Taking your first suggestion seriously, I did the math.  34.5 inches is 876.3 millimeters.  That doesn't sound like a likely size for a wheel, so I doubt that it's a conversion error.  850 or 900 mm sound like more likely sizes.

[Ike the BN Freak]

My thoughts are it was a marketing decision by IM, instead of doing both 33" and 36" wheels, they split the difference and got 34.5" making it a one size fits all

[sd45elect2000]

34.5" isn't a real wheel size (although a 36" wheel might wear down...) but given the explicit "for MicroTrains" trucks included in the advertising it might be to match a funky out of scale wheel size from MT and keep the couplers/ride height the same.

Although it seems the different would be pretty slight in N scale.

You might be surprised just how many wheels sizes there are.

[nkalanaga]

True, there are only a few standard sizes for interchange equipment, but a builder could put any size on something that would stay at home.

[narrowminded]

Are they the ones advertised as MT replacements? I bought some when they first came out and noticed they were larger diameter than FVM. They didn’t advertise the larger size then, that I noticed, so I assumed they were 33” when I bought them. I used them on some express boxcars that run with passenger equipment and have express trucks that kind of hide the size difference. I found it to be quite noticeable on regular freight cars/trucks.

Kind of put me off IM wheels. Can’t get imagine why they did that,’but at least they are telling people what size they are now.

Tom L
Wellington CO

I think somebody got a load of 5.5mm wheels.  A mistake.  Figure out what they are (34.6")  and sell them for what they are.  34 1/2" sounds plausible.

[sd45elect2000]

I think somebody got a load of 5.5mm wheels.  A mistake.  Figure out what they are (34.6")  and sell them for what they are.  34 1/2" sounds plausible.

Don't think for a moment that every wheel on the US car and locomotive fleet are the same. A 33 inch wheel is 33 inches at its condemning limit.
 Same with locomotive wheels. For example a 36 inch locomotive wheel is 36 inches when it is thrown away. Usually on a single wear wheel they have two inches of tread making the actual wheel diameter a 40 inch wheel. A fat or double wear wheel will be about 43 incheswith three inches of tread. Most freight car wheels are single wear, a new (so called) 33 inch wheel should actually measure 35 inches with 2 inches of tread. Not enough to worry about.