Help needed with wheel size problem

[jano11]

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

[klutz_100]

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

[jano11]

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

[gionc]

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.

[MPWR]

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....

[jano11]

Originally Posted by MPWR

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!

[jano11]

Originally Posted by gionc

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?

[klutz_100]

Ioan,

I came up with these:

http://www.automotiveforums.com/vbul...06&postcount=9

http://www.automotiveforums.com/vbul...wheel+diameter

http://www.automotiveforums.com/vbul...wheel+diameter

http://www.automotiveforums.com/vbul...wheel+diameter


HTH

[gionc]

Originally Posted by jano11

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/vbul...d.php?t=884414

[jano11]

Thanks for your help guys!

Steven you are making miracles with the search system!
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

[valdispert]

http://www.miata.net/garage/tirecalc.html

[jano11]

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.

[jano11]

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.



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

[valdispert]

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

[jano11]

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