WinFreak

I actually think that wheels have a tougher life on the street than on track... especially in pothole nation here

chilled

I ran rotas with Yoko A048R's without issue. Great wheel for the money. As HEL say, yes, we'd all love some Rays or whatever, but bang for buck I don't think you can beat Rotas.

s2konroids

No problem with Rota's here, however they havent been on a track. I know a few lads who have and have had no problems.

Ultra_Nexus

Mark,

You are a good man, but you are lacking knowledge here

Yes, I am assuming. However, unlike the Rota doubters, I admit to it and I hope the pictures of the premium wheels that have broken show that anything against rota is based on complete and snobishness. I can't recall anyone on here having a Rota wheel failure

Shelf life is VERY important. With Aluminium alloys, they gradually get weaker each time they are load cycled. A highly load cycled item has a much lower stress failure point than a new wheel.

A wheel forged from billet...well, this is a contradiction. Since forging uses liquid alloy, the second it is melted, it doesn't matter whether or not it was a billet as the inherent structural properties you get from a billet dissapear. Obviously, these will be replaced with the forged properties.

Now, forging does indeed produce stonger structures, however you cannot have both strength and lightness. The forged wheels are lighter, but they compromise their would be strength advantage as a result. Because these wheels are designed for out and out racing, they knowingly have a short load cycle life for the returned benefit of reduced weight.

MB

Don't think i'm lacking knowledge...

Your defenition of shelf life is not what i'd class as "shelf life" as in my game that's a term for a component which is sat unused and ageing. Hence I said it wasn't so relevant. If we look at fatigue cycle, that may be more relevant but I don't see how you can say a forged wheel has a lower fatigue tolerance than a cast one?

I don't agree that a forged wheel sacrifices strenght for weight reduction. Due to the forging process, less metal is used to obtain the same strength as a cast wheel, therefore with less weight. A cast wheel is generally designed to be heavier to take account of the porosity left from the casting process. If it's a light cast wheel, then you start having to question it's strength...

See here for a forged billet, which is then machined:

http://www.youtube.com/watch?v=7xn58aQowBA

CHIPPO

Not exactly a forging then, but a machined forging, so the machining will have cut through all of the grain flow that makes a forging stronger in the first place than that of a casting for a given weight. Off course as the original forging blank was formed the entire structure would have grain flow through the shape which would impart greater strength that that of the original material in the billet. After all the what i presume is a cold rolled billet has grain flow itself but not in the directions than one wants for the maximum strength of the finished product shape.

That bit of info is about 35 years old and has had a lot of soft ware errors added over the years in my numb head, so tin hat is on and i am down behind the parapit waiting to be shot.

WinFreak

That knowledge goes for many machined items, even simple as bolts, rolled threads are much stronger than cut ones.

CHIPPO

exactly, its basic engineering principles

MB

Machining or not (and I don't think many wheels are actually made from a pure forging) it's still a stronger process than a casting. A lot of the strenght in a forging is from the reduction of porosity.

But, the majority of wheels are cast and spend a lot of time on track - so i'm in no way saying cast wheels are shit!!!

I just think you get a stronger lighter wheel from a forged process.

CHIPPO

Yes you would according the theory in all respects, as i said gram for gram.

Cheaper would be a cheaper and quicker production process i would think usually

Edit , on serious drugs here , cheaper would be cheaper wouldnt it !!! I think "Casting" was the word in the front of my brain