Noticeable Difference with Lighter Wheels?

[BarManBean]

Another noob who likes to mince everyone's words??

 

How about you add material to the thin-ass spokes on the RPF1s. There, I haven't changed the design at all, but by making thicker spokes I've certainly strengthened the wheel at the expense of weight.

 

BTW, do you realize how condescending you sound?

[Ellesedil]

Nobody is trying to twist your words, or ruffle your feathers. I think we are about to have a breakthrough.

 

Let's brainstorm for a minute... Using your example again, how would you add that 4lbs of weight to your RPF-1? Where would you add material? How would you keep all other things equal? This is hard to do in the real world.

 

So now we're talking about altering the design of the wheel... and that's what I've been saying from the start: wheel strength is more a function of design than weight.

 

Just because a cheap wheel is weak, doesn't mean it's necessarily weak because it's light (could be weak because it's cheap, or poorly designed). Causation and correlation... there is a difference. There are plenty of heavy weak wheels too. Just ask the guy who bends expensive OEM wheels but not cheap Rotas that weigh less.

 

You could use a denser alloy, which would add weight and strength, without changing the design.

[LatentWagen]

Another noob who likes to mince everyone's words??

 

How about you add material to the thin-ass spokes on the RPF1s. There, I haven't changed the design at all, but by making thicker spokes I've certainly strengthened the wheel at the expense of weight.

 

BTW, do you realize how condescending you sound?

 

You're saying I sound condescending while calling me a noob. Meanwhile, I joined this site YEARS before you did

 

All I want to do is have a civil discussion about wheel weight. Can we, please?

 

So you want thicker spokes, huh? That's not a design change?

[LatentWagen]

You could use a denser alloy, which would add weight and strength, without changing the design.

 

Maybe, but would a denser alloy necessarily add strength? From what I understand, density and strength are not as correlated as we might think. Would the wheel then be softer, more prone to deforming? Or would it be brittle, and prone to cracking/failure?

 

I think we need a metals expert in here. And maybe a mediator

[BarManBean]

Yay, you signed up before I did. 80 posts, 10 of them arguing here, equals noob in my book. I'm sure you know your way around subies but it's just not showing here, sorry (and it really doesn't matter--many 1st posts are useful and many new folks contribute valuable info just as a lot of old salts contribute nothing but crap ).

 

And no, slightly thicker spokes is not a "design change", IMO. Is it different? Yes, of course it is--especially since the difference is due to adding 4 extra lbs of material as in the example being discussed.

 

By denser he obviously meant stronger. This is what I mean by mincing words--knock it off, it's not helpful and it doesn't serve to "have a civil discussion about wheel weight" when all you want to do is nit-pick whatever anyone says. Cost being equal, a wheel manufacturer choosing a heavier material versus a lighter one is obviously going to do so in order to increase strength. If strength wasn't a factor they would simply go with the lighter weight material at the same cost.

[LatentWagen]

Yay, you signed up before I did. 80 posts, 10 of them arguing here, equals noob in my book. I'm sure you know your way around subies but it's just not showing here, sorry (and it really doesn't matter--many 1st posts are useful and many new folks contribute valuable info just as a lot of old salts contribute nothing but crap ).

 

And no, slightly thicker spokes is not a "design change", IMO. Is it different? Yes, of course it is--especially since the difference is due to adding 4 extra lbs of material as in the example being discussed.

 

By denser he obviously meant stronger. This is what I mean by mincing words--knock it off, it's not helpful and it doesn't serve to "have a civil discussion about wheel weight" when all you want to do is nit-pick whatever anyone says. Cost being equal, a wheel manufacturer choosing a heavier material versus a lighter one is obviously going to do so in order to increase strength. If strength wasn't a factor they would simply go with the lighter weight material at the same cost.

 

Sorry to mince words again... but you're making my point. If I may, you said: "By denser he obviously meant stronger."

 

That's what I don't agree with. A denser metal is not necessarily stronger. Titanium is stronger than lead, for example.

 

And sorry for my lack of posts. I doubt I'll ever catch up to you.

[BarManBean]

I'm not making your point. Read the entire comment rather than just the handful of words that you think makes your point.

 

Cost being equal, and staying in the realm of wheel manufacturing (don't bring up titanium or lead, please), CHOOSING (by choice, and for a design / construction reason) a heavier material will be for the basis of strength. Again, cost and strength being equal, any manufacturer is going to choose a lighter weight material every time.

 

But that's not usually the case. Lighter materials suitable for wheel construction cost money. And in nearly all cases a lighter material with similar strength will cost more than a similarly strong material that weighs more.

 

And just to be clear, when you say:

A denser metal is not necessarily stronger

that's obviously true. However, in constructing a wheel, and in assuming that cost of the two materials are equal, no manufacturer is ever going to choose a weaker&denser material. That's a total lose-lose choice.

[Ellesedil]

Yeah, I was kinda assuming that the alloy picked out would be based on some sort of intelligent thought process when I made that comment....

 

If you want to make your wheels out of mercury for the hell of it, good luck.

[DeltaNu1142]

Yeah, I was kinda assuming that the alloy picked out would be based on some sort of intelligent thought process when I made that comment....

If you want to make your wheels out of mercury for the hell of it, good luck.

That would be expensive. And you could only use them at -40 degrees. There's a little bait for someone...

 

I think we can chalk this whole thread up to varying degrees of semantic tolerance.

[stalintc]

I think the point of all of this (aside from the mercury bit, which would just be crazy [literally due to the material's interaction with humans...]) is that weight is the dependent variable in the equation of wheel construction. You can increase weight (or mass if we want to be quite specific) but that alone will not necessarily change the strength, design, process, etc. However if you change the design, material, process etc the mass will be affected (assuming no other change is made to counter act it).

 

IMO any change that affects the styling, physical construction, materials, and or any physical property is a design change, especially in the eyes of an engineering company. For example, if one were to change the insulating jacket on a single wire that is in a vehicle for production a slew of paper work would be necessary, including several "design change" title documents (but hopefully no TPS reports).

 

Anyway, thanks to all for the information and experience. I am glad to hear about the Enkei and cracking as I was looking at those.

[Ellesedil]

Anyway, thanks to all for the information and experience. I am glad to hear about the Enkei and cracking as I was looking at those.

 

Any wheel can break at any time. Enkeis are actually pretty decent wheels and you have no information on the circumstances that led to those wheels cracking, not to mention being a small sample size even if the circumstances are "reasonable" (whatever that means).

 

Instead of deciding against a brand because soandso on some internet forums cracked one for unknown reasons, you should do some more expansive research. Otherwise, you will never ever find a brand of wheels to buy because there will always be someone to say "I broke one of those."

[stalintc]

Any wheel can break at any time. Enkeis are actually pretty decent wheels and you have no information on the circumstances that led to those wheels cracking, not to mention being a small sample size even if the circumstances are "reasonable" (whatever that means).

 

Instead of deciding against a brand because soandso on some internet forums cracked one for unknown reasons, you should do some more expansive research. Otherwise, you will never ever find a brand of wheels to buy because there will always be someone to say "I broke one of those."

 

This is a fair point. I did a basic search on the Googles and and found some stuff on the RPF1 when I posted that, but in comparison to other wheels and similar searches it seems to put it in a different light.

 

As they say in England: Touche

[Sideways the Seven]

Eh, I had Rotas, and they felt like they were made from cinder blocks and would actually dent the road itself before they broke. They gave the car a very planted feel versus the wheels that were on it when I bought it (17x7 Enkei ZR1 on 225/55/17). That being said, I know there are TONS of other wheels out there that might be "better", but I wouldn't have any problem recommending them to someone else that may be looking for a nice-looking wheel that never gave me any issues.

[iNVAR]

So now we're talking about altering the design of the wheel... and that's what I've been saying from the start: wheel strength is more a function of design than weight.

I don't consider that a design alteration. Otherwise, going from a 17" RPF1 to an 18" RPF1 would be considered a completely different design. No one calls it a different design. They are both the same design, but different size, and by necessity, also a different weight.

 

I'd probably thicken up the spokes a bit and thicken up the barrel some. The design is still the same. Just heavier, and stronger. Weight isn't the cause, thanks. I know the difference between causation and correlation and evidently, so does DM. That's why he said, "almost guarantee" because again, all things being equal, the heavier one will be stronger. You can call this a design change if you want, but then we'd just be arguing semantics.

[Drift Motion]

man this blew up...

[stalintc]

man this blew up...

 

"not a laaaawt juz a lill biiiit..."

[LatentWagen]

Have you noticed a real difference when switching to a lightweight wheel and if so in what way? I have read what theoretically will happen, however I am not on a track, I have stock suspension, etc.

 

For the sake of the question, I am looking at about 2-3 lbs per wheel of slim-fasting.

 

Thanks

 

UPDATE:

General consensus is that on the road, normal driving, non-race car driver people will notice no difference due to wheel weight reduction. Any differences found are either due to tire width / diameter changes and or placebo effect. Feel free to read through to see all sides of the question. Design arguments start at the bottom of pg 3

 

I think it's time for another update, from this month's C&D:

 

http://i66.tinypic.com/2qa2wbb.jpg

 

Just goes to show that the "general consensus" is not always correct.

[whitetiger]

well, yeah, thats what happens when you take off 58lbs total of rotating mass. accelerate faster, brake harder, and turn easier.

 

gotta love race cars.....

[LatentWagen]

well, yeah, thats what happens when you take off 58lbs total of rotating mass. accelerate faster, brake harder, and turn easier.

 

gotta love race cars.....

 

58lbs of rotating mass is almost exactly how much rotating mass I took off going from the stock spec B. wheels to the SSRs. More, if you count the 2pc rotors.

 

Point being, there is a huge difference in acceleration (and inertial mass, look at the 200ft coast difference) when you drop wheel weight, contrary to the all knowing general consensus. These tests were done on a street (lol, kinda) car, not a race car.

[whitetiger]

of course. i always feel the difference with lighter wheels. i'd never wright it off as negligible on the street. and the the GT350 is sort of a street car as you said.

[LatentWagen]

If I didn't sell my stock wheels, this would be a really interesting test to replicate... I'd think that the lower power of our cars would make removal of rotating mass even more beneficial (just a hunch though). I also want to see lower-gear comparisons, because nobody is pulling 30-50 in 6th, we'd run out of road/gas first

 

Maybe someone else local with a spec B (or just the wheels) would be willing to help test this out? Probably would have to account for rolling diameter differences, too though.

[whitetiger]

^i have 2 sets of identical measurement wheels for my mx-5. 17x9 + 48. 1 set is 19lbs per wheel, the other is 17lbs per wheel. the lighter ones are faster noticeable.

[fedaykin]

Easier to remove/install.

[Drift Motion]

anyone want to buy carbon fiber wheels?

 

starting at $1000 a piece

[boxkita]

anyone want to buy carbon fiber wheels?

 

starting at $1000 a piece

 

that's actually a good price, assuming these are the Konisegg wheels?

 

RPF1 lighter equals fragile argument still going on? Get over it. Just lighter. The PF01 is better because it prevents the tire from slipping on the rim and throwing off the balance. However, that only matters on racecar.

 

Cracking a RPF1 wheel is as likely as cracking a Rota boat anchor wheel. No, really.