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Hi Guys,

I'm Having a real hard time deciding on rim size for my 1/25 Kenworth Aerodyne BJ build and I need some expertise please.

I thought it would be as easy as 1/25 scale rig/trailer - 1/25 rims. I'm using the 1/25 Revell Aerodyne and the 1/25 ERTL Reefer. To be honest the kit rims on the 1/25 trucks seem too small to me. They measure out to be 23.5mm in diameter.

Can anyone answer whether the K-100 from Factory and particularly the BJ and the Bear Kenworth had 22.5 or 24.5 inch Alcoa rims? Was one a standard factory option over the other? In 1/25 scale that would measure out to be roughly 22.8 or 24.8mm in size. Kit rims are 23.5mm. I do have some nice aluminium rims that are 1/24 and measure out to be 26.7mm. Although the scale would dictate to use 1/25 rims, my eye tells me different in that the 1/24 scale rims might look better?

Does anyone have experience fitting 1/24 rims to 1/25 trucks? There seems to be quite a size difference. Using 1/24 rims will result in width issues. 

I've tried to do a bit of a side on comparison with a Revell rig but note the height of the picture is not uniform in both pics so that could alter the view and I don't really know what i'm doing!

sidebyside-A.jpg

IMG-7997.jpg

 

comp.jpg

 

IMG-8001.jpg

opinions?

 

cheers.

chris

 

 

 

 

Edited by CharlieBravo
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In the BJ & the bear era the 24.5 would have been the popular choice, especially for the O/O crowd. As far as width most axles are set for a 96" width but with the increase in trailer width to 102" axles are becoming wider as well. JUst explain that on a rebuild you went with the wider axles "for stability" and everybody be happy. ☺

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The TV series truck by studying footage and pictures of the restored truck , it appears that it was equipped with 24.5 wheels which makes all 1/25 kit wheels too small. I also have this build in the works . Initially I had planned to use the rear wheels from the AMT Freightliner Kit ( these are the best looking IMO kit wheels) which are 22.5 . And I was going to use the front wheels out of the ERTL/ AMT 4300 Transtar kit and use the ERTL tires ( old MPC tooled) . Tires are 11:00x20 but when put on the Freightliner rims do look right .  I may go with aftermarket wheels and tires yet but I do like staying with kit stuff. Those are my thoughts.

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Only advice I can offer ..when I order aftermarket tires , they ask which wheel I'm using . Gary's 22 inch drives in 1/25 scale fits on a 20 inch wheel.  Jamie's aka moluminum is the same . These both fit mobius wheel sets . 

 

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2 hours ago, PettyKW43 said:

The TV series truck by studying footage and pictures of the restored truck , it appears that it was equipped with 24.5 wheels which makes all 1/25 kit wheels too small. I also have this build in the works . Initially I had planned to use the rear wheels from the AMT Freightliner Kit ( these are the best looking IMO kit wheels) which are 22.5 . And I was going to use the front wheels out of the ERTL/ AMT 4300 Transtar kit and use the ERTL tires ( old MPC tooled) . Tires are 11:00x20 but when put on the Freightliner rims do look right .  I may go with aftermarket wheels and tires yet but I do like staying with kit stuff. Those are my thoughts.

Do you have any pics of them?? Would be curious to see how they look!! 
Thank you!

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On 4/16/2020 at 4:08 PM, PettyKW43 said:

The TV series truck by studying footage and pictures of the restored truck , it appears that it was equipped with 24.5 wheels which makes all 1/25 kit wheels too small. I also have this build in the works . Initially I had planned to use the rear wheels from the AMT Freightliner Kit ( these are the best looking IMO kit wheels) which are 22.5 . And I was going to use the front wheels out of the ERTL/ AMT 4300 Transtar kit and use the ERTL tires ( old MPC tooled) . Tires are 11:00x20 but when put on the Freightliner rims do look right .  I may go with aftermarket wheels and tires yet but I do like staying with kit stuff. Those are my thoughts.

The AMT Freightliner wheels are 22 inch split rims with a lock ring for tube tires so they wouldn't be right as the inside of the rim is flat all the way from the inside and out, wheels for 22.5 and 24.5 inch tubeless tires has a depression in the middle of the rim and no lock ring, so the Freightliner wheels wouldn't look right if you are picky.

I think I would go for 22.5 inch wheels in 1:24th scale wich should be close to 24.5 inch in 1:25th scale.
it's not easy to find wheels with the right look and decent scale size as most of the wheels in kits are not that good and haven't got the right look, so aftermarket is most likely the only way to go.
I would like to see correct good looking 22 inch split rim front wheels for my Movin' On and Smokey and the Bandit truck projects still in the planning stage waiting for the right parts, nothing is available in resin and none of the kit wheel has the right look.
I might have to contact Doug Wagner at Keystone and hear if he would like to do a set or two for me, he has good looking machined aluminum 5 hole split rims in a couple of sizes but no 10 hole other than tubeless tire style.

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As mentioned, the real truck had 24.5" rims. This measurement is taken at the bead of the tire, so the actual outside diameter of a real rim will be larger than 22.5 or 24.5 inches respectively. The aftermarket rims from Moluminum are perfectly in scale, he offers both 22.5" and 24.5" rims. Doug Wagner also offers machined aluminum 24.5" rims in 1/25 scale that are perfectly to scale. If you want the most accurate looking build to the real thing, I would say use Doug's aluminum wheels. It is an expensive option, but it is the most accurate way to go. Moluminum's resin wheels would be my next choice.

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While in 1:1 world the tire size is measured on the inside of the bead, in the modeling world we really need to know what the visible diameter of the rim is.  I do that for passenger car wheels and it would be nice if this info was provided by aftermarket manufacturers (for both the tire and rim).  Also, some model rims do not have any lip, others do. Same goes for model tires. That complicates trying to  find the right wheel/tire combo.

In passenger tires/wheels, the larges visible rim diameter is about 1.5" larger than the specified 1:1 tire diameter.  So a 1:1 16" wheel will really have 17.5" diameter visible outside of the tire.

If the same holds true for trucks (I suspect that it does, then a 22.5" rim would actually have visible diameter of 24" and a 24.5" rim would have visible diameter of 26".

That would be respectively 1" in 1:24 scale; 0.96" in 1:25 scale, and 1.08" in 1:24 scale; 1:04" in 1:25 scale.  It would be very helpful if aftermarket manufacturers provided this type of dimensions to modelers.  That way it would be easier to find matching rims and tires.  American SATCO provided theses actual tire dimensions on their tire sets.

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12 hours ago, peteski said:

While in 1:1 world the tire size is measured on the inside of the bead, in the modeling world we really need to know what the visible diameter of the rim is.  I do that for passenger car wheels and it would be nice if this info was provided by aftermarket manufacturers (for both the tire and rim).  Also, some model rims do not have any lip, others do. Same goes for model tires. That complicates trying to  find the right wheel/tire combo.

In passenger tires/wheels, the larges visible rim diameter is about 1.5" larger than the specified 1:1 tire diameter.  So a 1:1 16" wheel will really have 17.5" diameter visible outside of the tire.

If the same holds true for trucks (I suspect that it does, then a 22.5" rim would actually have visible diameter of 24" and a 24.5" rim would have visible diameter of 26".

That would be respectively 1" in 1:24 scale; 0.96" in 1:25 scale, and 1.08" in 1:24 scale; 1:04" in 1:25 scale.  It would be very helpful if aftermarket manufacturers provided this type of dimensions to modelers.  That way it would be easier to find matching rims and tires.  American SATCO provided theses actual tire dimensions on their tire sets.

While I agree to some extent, it may make it even more confusing for some. Most of the model truck kits (AMT kits at least) come with older tube-type rims. These had a deeper lip, and were 20" or 22" when measured at the tire bead. For this reason, AMT tires are stamped as 20" or 22" on the sidewalls. In real life, when the switch to tubeless tires occurred, the lip on the rim became shorter, making a 22.5" tubless wheel equivalent to a 20" tube type, and a 24.5" tubeless wheel equivalent to a 22" tube type.

 

In general, a 20" tube-type rim and a 22.5" tubeless rim will have an OD of approximately 24.5" while a 22" tube-type and a 24.5" tubeless rim will have an OD of approximately 26.5".

 

The problem lies in that many people do not know the difference between tube-type and tubeless rims. Since many people want to use kit tires on aftermarket rims, many aftermarket manufacturers try to list the rim size to match the kit tire nomenclature, so they may call a 24.5" tubless rim a "22 inch rim" so that people know that AMT's 22" tires will fit on it.

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OK than, so it is not as clear-cut with truck wheels as it is with cars.  With cars, the 1.5" size difference between the stated bead size, and outside rim diameter is pretty much given.  I learned something new here - thanks.

I was also wondering why trucks have odd size rims (like 22.5), instead of full numbers used on cars (15, 16, 18).  But is seems that originally (with tube tires) rims did have full number sizes, and they gained the 0.5" when migrating to tubeless rims/tires.  If that  is accurate, it makes sense to me now.

Edited by peteski
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The question of scale is always a subjective one because model companies work with a more or less, "that looks about right" scale.  They will be close but the differences in how they put things together means that they may not always interchangeable across brands, or for that matter model to model a single brand.  They often try to get close, but they make sacrifices for the eyeball appeal and manufacturing expediance. 

For that reason, measuring is critical.  Most resin companies will specify a particular kit or manufacture to assist with your choice.  Some also give ID and OD.   

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19 hours ago, peteski said:

OK than, so it is not as clear-cut with truck wheels as it is with cars.  With cars, the 1.5" size difference between the stated bead size, and outside rim diameter is pretty much given.  I learned something new here - thanks.

I was also wondering why trucks have odd size rims (like 22.5), instead of full numbers used on cars (15, 16, 18).  But is seems that originally (with tube tires) rims did have full number sizes, and they gained the 0.5" when migrating to tubeless rims/tires.  If that  is accurate, it makes sense to me now.

It's a bit more, they went from 20" to 22.5" and from 22" to 24.5" when they migrated from tube tires to tubeless tires, so the difference between tube rims and tubeless rims is 2.5"...but I don't know the reason to why they decided on just those numbers.

Edited by Force
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5 hours ago, Force said:

It's a bit more, they went from 20" to 22.5" and from 22" to 24.5" when they migrated from tube tires to tubeless tires, so the difference between tube rims and tubeless rims is 2.5"...but I don't know the reason to why they decided on just those numbers.

If course - thanks!  Had a brain cramp . . .

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So on the Bear build I found out that rear wheels from a Freightliner Kit and the front wheels from a KW Aerodyne are close to what the Bear rig is.. Thinking that’s the way I’m going with mine. My buddy and I are ordering 22 inch resin 2 hole Buds, him for two trucks and trailers, me just for the trailer for my Bear build.. 

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It depends on how close to the real thing you want your model to be, the real BJ truck has 24.5 inch tubeless wheels and the AMT White Freightliner wheels are 22 inch lock ring style wheels for tube tires and they look different,  the rims for tube tires are flat and the rims for tubeless tires has a dip in the center of the rim wich is there so you can put the tire on the rim as the outside diameter of the rim is larger than the inside diameter of the tire bead.
But of course it's up to you what you want to use.

Here is a picture to explain what I mean.

profilecomparison.jpg.cf7a89cdce23736cbd5da6a6f95a85b4.jpg


I myself would go for the 22 inch 10-hole wheels Mo'luminum has on his website as they have the right look, the size on them says 22 inches but as they are tubeless style one piece wheels they have to be 24.5 inches and not 22, or one can go the more expensive way and get real aluminum wheels...but the resin wheels are a lot cheaper as you get 10 wheels for the same price as 2 aluminum wheels costs.
I don't know why Jamie has marked his tubeless wheels 20 and 22 inches when the sizes of real tubeless wheels are 22.5 and 24.5 inches, maybe it's to tell that the wheels will fit 20 and 22 inch kit tires.

Edited by Force
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