3 Piece Rims

[NSXType-R]

If a wheel is made of one piece, then how come rims sometimes have more than 1 piece, like sometimes I hear 3 piece rim, or two piece rim? If it's made in separate pieces, wouldn't that weaken the rim? So confused!

What exactly does the extra pieces do?

Thanks guys.

[baddabang]

I think this is what it is

The outside ring is heated up so it expands and the center is placed inside it. Then when it cools down it tightens around the ring and it is welded usually by a machine, this makes them very strong.

[johnnynumfiv]

Originally Posted by baddabang

I think this is what it is

The outside ring is heated up so it expands and the center is placed inside it. Then when it cools down it tightens around the ring and it is welded usually by a machine, this makes them very strong.

Yep.
Also some pieces are screwed into place(some BBS wheels).

[baddabang]

Originally Posted by johnnynumfiv

Yep.
Also some pieces are screwed into place(some BBS wheels).

Really that dosent compromise strength? Well obviously not BBS wheels are great

[RacingManiac]

I am not exactly sure as to why some wheels are made into 3 piece other than the fact that it allows for a specfic style of wheel to be made to different offset by bolting on different size shell. With possible benefit of in case of damage you might just need to replace the shell if they are bent...

[Quiggs]

Big lip. Small lip. Adjustability ftw.

[NSXType-R]

Thanks.

[culver]

For a time 3 piece wheels were lighter for their strength. The outside part of the wheel is spun steal. The hub was alloy. Basically this allowed engineers to use the thin, strong steal where it was optimal and aluminum or magnesium in the center where it's bulk was advantageous.
Another benefit was repair. A three piece wheel could be disassembled after a wreck. This isn't a big concern for street cars but it is for race cars. The three part wheels I’m familiar with have been bolt together wheels.

[coolieman1220]

it seems to me, not sure but is a built wheel cheaper then a forged becuase well forge, u need a block and just gets chunks cut and drilled out and laser cut. time and money and waste. but puttin pieces seems cheaper. can this be verified. sorry for the ands. lol

[johnnynumfiv]

You still have to manufacture the pieces though.

[h00t_h00t]

Standard alloys you get on most cars are made with much cheaper metal than wheels used in racing, so more metal needs to be used to give them strength and they end up weighing only slightly less than steel wheels.

In my experience Peugeot are the worst, but all of their standard wheels weigh more than other manufacturers.

[RacingManiac]

Originally Posted by coolieman1220

it seems to me, not sure but is a built wheel cheaper then a forged becuase well forge, u need a block and just gets chunks cut and drilled out and laser cut. time and money and waste. but puttin pieces seems cheaper. can this be verified. sorry for the ands. lol

The centers and the shells still needs to be made. The centers can be CNC machined from a billet or forged still. While the shells are spunned. The cost saving though comes from the fact as I mentioned before, by mating to different spunned shells(and most manufacturers makes the shells in variaties of sizes and combo), they can accomodate different dimension fairly easily. While a forged/cast one piece are limited by the mold, and retooling costs a lot of money. In those cases then you need to resort to adapter or spacer....