Help needed with wheel size problem

Hi everyone,

I'm in the process of making the first custom wheel for a future project.
The dimensions of the wheel/tire combinations are:

Front: 9.0 J x 21 - 245/30 ZR21
Rear: 12.0 J x 21 - 345/25 ZR21

I would need to know what are the exact sizes for 1:24 scale wheels for:
a. the outer diameter of the rim
b. the outer diameter of the tire

Thanks in advance for your help!


Ioan

Hi Ioan,

Something similar to this has apperared in the past IIRC

As I recall ZoomZoom posted a very good chart. Try searching for it (I'll also see if I can find it)

S

Thanks for the info Steven!
I already looked but only managed to find 2 images posted by hiroboy, and they were only about the rims up to 19 inch.

I'll search again, however if you happen to find it please do post a link!

Thanks,

Ioan

Consider a thing: our eyes are used to see oversized rims in scale. The R8 Revell rims are correct in scale but they seems very small in diam. and narrowed. A tamiya 19" Enzo rim would be in real life 23 or 24 inches, same for Fujimy: 430 19" are 23 or more inch in 1/1.

When I done the 430 Scuderia rims by rapid prototyping I used (obviously) same (over)-sized Fuji rims (TBH a little bigger), if I must to do a whole scratch rim I would use same Tamiya (or similar manufacturers) dimensions.

Just your choice: or "matematically" accurate or "modelling accurate", or better accurate "by eyes", not by ruler.

Wheels have a lip 1/2" to 3/4" high, which adds 1" to 1 1/2" to the diameter of the wheel. So your 21" wheels will essentially look like they are 22" or 22 1/2". If you want to know what that is in 1/24, just divide it by 24- slightly less than an inch.

Outside tire diameter is slightly more obnoxious, but by no means difficult. 245/30 ZR21 means that the tyre is 245mm wide, and the sidewall height is 30% if that. So, multiply 245 x 0.30. Then multiply that by two (because there is sidewall above and below the wheel), divide it by 25.4 to convert to inches, and add that to 21". I got 26 3/4", so in 1/24 that's slightly more than an inch.

Math is your friend....

Wheels have a lip 1/2" to 3/4" high, which adds 1" to 1 1/2" to the diameter of the wheel. So your 21" wheels will essentially look like they are 22" or 22 1/2". If you want to know what that is in 1/24, just divide it by 24- slightly less than an inch.

Outside tire diameter is slightly more obnoxious, but by no means difficult. 245/30 ZR21 means that the tyre is 245mm wide, and the sidewall height is 30% if that. So, multiply 245 x 0.30. Then multiply that by two (because there is sidewall above and below the wheel), divide it by 25.4 to convert to inches, and add that to 21". I got 26 3/4", so in 1/24 that's slightly more than an inch.

Math is your friend....

Thanks for the help!

Maths were not the problem.
I had no idea about how high the lip of a 21" wheel is nor that the tire sidewall height is 30% of it's width!

Consider a thing: our eyes are used to see oversized rims in scale. The R8 Revell rims are correct in scale but they seems very small in diam. and narrowed. A tamiya 19" Enzo rim would be in real life 23 or 24 inches, same for Fujimy: 430 19" are 23 or more inch in 1/1.

When I done the 430 Scuderia rims by rapid prototyping I used (obviously) same (over)-sized Fuji rims (TBH a little bigger), if I must to do a whole scratch rim I would use same Tamiya (or similar manufacturers) dimensions.

Just your choice: or "matematically" accurate or "modelling accurate", or better accurate "by eyes", not by ruler.

Thanks for the info Gio! I'll have to take a look at how a 21" wheel would look and then decide if I should go for a bigger one.

BTW, where did you do the rapid prototyping, if I may ask?

Ioan,

I came up with these:

http://www.automotiveforums.com/vbulletin/showpost.php?p=3503406&postcount=9

http://www.automotiveforums.com/vbulletin/showthread.php?t=749631&highlight=wheel+diameter

http://www.automotiveforums.com/vbulletin/showthread.php?t=682282&highlight=wheel+diameter

http://www.automotiveforums.com/vbulletin/showthread.php?t=682282&highlight=wheel+diameter


HTH

Thanks for the info Gio! I'll have to take a look at how a 21" wheel would look and then decide if I should go for a bigger one.

BTW, where did you do the rapid prototyping, if I may ask?
I work with a service due my job (product designer), luckyly the service is 25/30 Km close to my home, they got several prototyping tech, from 16 micron/layer 3d printing to industrial STL and syntherizathion (nylon powders an liquid resin laser forming). They aren't the cheaper I found but the best looking at quality. I guess they won't work outside Italy, and they accept my little toys toghether with my job's stuff, anyway I'll give you a contact, you'll try. Name is TOPP prototyping, sandrigo-Vicenza, Italy.

Following the link to the rim I done.
http://www.automotiveforums.com/vbulletin/showthread.php?t=884414

Thanks for your help guys!

Steven you are making miracles with the search system! :thumbsup:
Gio, thanks for the info, I'll se if I find someone close to where I live otherwise I might get in touch with your contact.

Thanks again,

Ioan

Thanks for the tire calculator. Excellent tool!

Does anyone know which kit comes with tires that have an inner diameter of around 25.5 mm? Or maybe a set of aftermarket wheels with this size?

I'll try to post a pic of the wheel in a few moments.

Here's the 3D model of the wheel I want to use. I hope I'll get a 3D printing service to do it for me.

http://images33.fotki.com/v1186/photos/1/1338644/6237714/wheelassembly-vi.jpg

However I'll need the right tires for it, as I'm not to enthusiast about making the model of a tire too.

25,5 X 24 = 612mm
612mm = 24" (but you should look for a 23", read the above posted links)

You are right, I got carried away a bit.

21"=533,4mm +
2*flange=35-36mm
________________
= 569,6mm in 1:1 scale and 23.7mm in 1:24 scale

I should be looking for tires with inner diameter of 23.5 to 24 mm.
If anyone know where to find them, please let me know.

Thanks again for your help!

Ioan