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      12-24-2009, 07:33 AM   #1
m3pyun
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understanding 2 piece wheel construction

Wheel experts help me out! I understand that a 2 piece wheel consists of the barrel and the face. The face can be attached to the barrel in 1 of 3 ways: welded, rivets on the face, rivets on the back (for the rivet less look). When rivets are used on the face of the wheel there are nuts that are used on the opposite side. However, when a rivet is used on the back, it screws directly into the face of the wheel. Wouldn't that mean the part of the face that attaches to the barrel needs to be fairly thick to allow the rivets to screw into it and have enough strength? Which leads me to my next question, doesn't that take away from the lip size and add weight as well?
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      12-24-2009, 08:41 AM   #2
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Quote:
Originally Posted by day1yun View Post
Wheel experts help me out! I understand that a 2 piece wheel consists of the barrel and the face.
Correct.

2-piece wheels consist of a wheel CENTER (spoke section) that uses a conventional or rotary forging made from round bar stock, low pressure casting, or billet machined from aluminum plate. This mated to a outer rim section that is formed from pressed & rolled sheetmetal.


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Originally Posted by day1yun View Post
The face can be attached to the barrel in 1 of 3 ways: welded, rivets on the face, rivets on the back (for the rivet less look). When rivets are used on the face of the wheel there are nuts that are used on the opposite side. However, when a rivet is used on the back, it screws directly into the face of the wheel. Wouldn't that mean the part of the face that attaches to the barrel needs to be fairly thick to allow the rivets to screw into it and have enough strength? Which leads me to my next question, doesn't that take away from the lip size and add weight as well?
YES, assuming it was properly engineered in the first place. (which is certainly not a given with many of the wheels on the market today)

It 'may' cost you a little real estate in regards to a larger lip (depending on the design of the center forging itself), and YES it could add additional weight to the wheel as well. However, it should be noted that there are weight saving CNC machining techniques that can be used to offset the added weight of the thicker center section.

By machining out weight saving 'pockets' (in low stress areas) on the backside of the wheel center forging (and back pad areas), you can effectively reduce the overall weight of the heavier, thicker center forging.

Again, that is assuming the wheel company properly engineers this into the equation from the beginning. It cannot be done after the fact on just any design they have in their lineup. There is no responsible way to 'reverse engineer' this design element into an existing design. You must go back to the drawing board and start over from scratch.
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Last edited by Lemans_Blue_M; 12-24-2009 at 10:51 AM.
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      12-24-2009, 09:12 AM   #3
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Quote:
Originally Posted by Lemans_Blue_M View Post
Correct.

2-piece wheels consist of a wheel CENTER (spoke section) that uses a conventional or rotary forging made from round bar stock, low pressure casting, or billet machined from aluminum plate. This mated to a outer rim section that is formed from pressed & rolled sheetmetal.




YES, assuming it was properly engineered in the first place. (which is certainly not a given with many of the wheels on the market today)

It 'may' cost you a little real estate in regards to a larger lip (depending on the design of the center forging itself), and YES it could add additional weight to the wheel as well. However, it should be noted that there are weight saving CNC machining techniques that can be used to offset the added weight of the thicker center section.

By machining out weight saving 'pockets' (in low stress areas) on the backside of the wheel center forging (and back pad areas), you can effectively reduce the overall weight of the heavier, thicker center forging.

Again, that is assuming the wheel company properly engineers this into the equation from the beginning. It cannot be done after the fact on just any design they have in their lineup. There is no responsible way to 'reverse engineering' with this type of thing with an existing design. You must go back to the drawing board and start over from scratch.
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      12-24-2009, 12:07 PM   #4
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      12-24-2009, 12:45 PM   #5
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Quote:
Originally Posted by Lemans_Blue_M View Post

Again, that is assuming the wheel company properly engineers this into the equation from the beginning. It cannot be done after the fact on just any design they have in their lineup. There is no responsible way to 'reverse engineer' this design element into an existing design. You must go back to the drawing board and start over from scratch.
That is incorrect. If a wheel was properly designed from the start, and than later on the designers wanted to add in the weight saving pockets this COULD be perfectly acceptable (assuming the proper use of FEA to ensure strength).

Obviously if a wheel is near the limit of "acceptable" without the pockets, the pockets would most likely place the wheel in the "unacceptable" range. But saying a designer CAN NOT, under no exception, come back and alter a current design is wrong.
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