## Carbon Fibre wheels

Here are our CFD links and discussions about aerodynamics, suspension, driver safety and tyres. Please stick to F1 on this forum.
0
F1_eng wrote:Tom, I am strugling to see what your point is.
What do you mean by "power that you're freeing up"?

Takes a certain amount of power to accelerate a given amount of inertia at a given rate. Lower the inertia, and you're reducing that power requirement. It's like getting extra free engine power to make the car accelerate faster.

My point is, for a lot of parts (ex: hub), the linear inertia can be much more significant than rotational.

Yes, you take any small gain you can.. but people make a big deal out of the fact it's rotating when on a relative order of magnitude comparison, it's not as big as some would indicate.

The F1 team that I work for certainly can quantify the effect of varying vertical force on available latteral force, any team that has the resources to analyse this and doesn't would be foolish. Afraid I can't give anymore detail.

I just highly doubt this. A 7-post rig will not really give you the answer. They're great tools for sure, and a team probably won't be competitive without one, but it's only half the puzzle. (Plus the tires don't rotate and may or may not be at the right temperature)

I'm talking about measuring dynamic tire forces and quantifying relaxation lengths in multiple directions. I don't know of a test machine on earth that can quite pull this off at real race speeds and loads.
Grip is a four letter word.

2 is the new #1.
Jersey Tom
127

Joined: 29 May 2006
Location: Huntersville, NC

0
all wishbones in F1 are CF parts so I don´t see why it would´t be feasible to do a cf rim for formula 1 if t were allowed.For sure the benefits of having cf /ti composite suspension are very limited .
On the other hand one has to remember F1 is running still on very small diameter rims so rotational inertia from the rim is not as severe as on motorcyle or touring/sportscar 18/19´´.
marcush.
102

Joined: 9 Mar 2004

0
Jersey Tom wrote:Takes a certain amount of power to accelerate a given amount of inertia at a given rate. Lower the inertia, and you're reducing that power requirement. It's like getting extra free engine power to make the car accelerate faster.

My point is, for a lot of parts (ex: hub), the linear inertia can be much more significant than rotational.

Yes, you take any small gain you can.. but people make a big deal out of the fact it's rotating when on a relative order of magnitude comparison, it's not as big as some would indicate.

If you are trying to say that you are better off reducing mass with non rotating components then I really do not understand the logic.

Like if I where given a choice to loose some weight in the uprights or the hub/wheel. I would definitely choose the hub because I loose the same amount of linear inertia while also gaining by "freeing up power" as you said.

On the other hand one has to remember F1 is running still on very small diameter rims so rotational inertia from the rim is not as severe as on motorcyle or touring/sportscar 18/19´´.

I guess the F1 rims being wider will have only little less rotational inertia than the 18+ inch rims.

Just out of curiosity, can anyone tell me the number of sets of wheels a team uses per season in different series. Just to give an idea of quantity required to estimate the extra cost for CF rims.
The_Man
0

Joined: 15 Mar 2009
Location: Mumbai India

0
The_Man wrote:
Jersey Tom wrote:Takes a certain amount of power to accelerate a given amount of inertia at a given rate. Lower the inertia, and you're reducing that power requirement. It's like getting extra free engine power to make the car accelerate faster.

My point is, for a lot of parts (ex: hub), the linear inertia can be much more significant than rotational.

Yes, you take any small gain you can.. but people make a big deal out of the fact it's rotating when on a relative order of magnitude comparison, it's not as big as some would indicate.

If you are trying to say that you are better off reducing mass with non rotating components then I really do not understand the logic.

Like if I where given a choice to loose some weight in the uprights or the hub/wheel. I would definitely choose the hub because I loose the same amount of linear inertia while also gaining by "freeing up power" as you said.

I'm saying the same thing marcush is. Don't know how much simpler I can write it out.

The fact that something in the wheel assembly is rotating isn't as significant as some make it out to be. Of the energy required to accelerate a given component, the linear contribution can be much larger than the rotational.

It's an observation.
Grip is a four letter word.

2 is the new #1.
Jersey Tom
127

Joined: 29 May 2006
Location: Huntersville, NC

0
scarbs wrote:Carbon fibre wheel are easily available for motorcycles, they seem durable although bikes don’t to clash their wheels each other or armco! the reduction in mass benefits acceleration and unsprung weight. I see no reason why carbon car wheels couldn’t be manufactured. They are of course banned in most forms of motorsport and motorcycling.

Because they have poor behaviour in critical 'shock loading' situations. Once there's a crack you're fcked.

I've a nice video on track somewehere of someone up ahead in an Aprilia RSV Mille with a nice BST carbon wheel set where the rear quite literally turned into carbon shards coming out of a corner.

Jersey Tom wrote:I know of at least one FSAE/FStudent team with very trick looking super light carbon wheels, where its a weight penalty. The thing doesn't hold air worth --- so they have to run a tube.

FSAE teams don't load their wheels nearly as much, apply far greater safety factors, don't have access to metal alloy forging capabilities and most importantly, FSAE teams don't race so the life cycle can't really be compared.
SZ
0

Joined: 21 May 2007

0
SZ wrote:FSAE teams don't load their wheels nearly as much, apply far greater safety factors, don't have access to metal alloy forging capabilities and most importantly, FSAE teams don't race so the life cycle can't really be compared.

Man you need to see better FSAE teams.....
RacingManiac
4

Joined: 22 Nov 2004

0
On the contrary - I've seen championship winning FSAE teams. Good attempts at this problem and those poorer. Some students do do fantastic work, though less stress the important bit: FSAE teams do not race, and as such the life cycle is not comparable. A long way off.

(I'll leave out the other truths that might sound like criticisms, however) FSAE teams might have access to forged wheels but (correct me if I'm wrong) I'm yet to see a team turn out with a custom forged design in an alloy of choice pending their specific needs, which is par for the course in F1.
SZ
0

Joined: 21 May 2007

0
SZ wrote:
Jersey Tom wrote:I know of at least one FSAE/FStudent team with very trick looking super light carbon wheels, where its a weight penalty. The thing doesn't hold air worth --- so they have to run a tube.

FSAE teams don't load their wheels nearly as much, apply far greater safety factors, don't have access to metal alloy forging capabilities and most importantly, FSAE teams don't race so the life cycle can't really be compared.

The FOS on my parts (according to FEA by von Mises criterion anyway) ranged from 0.98 to 1.15.

Surprisingly enough the "0.98" part worked flawless and remained almost unchanged every year since I designed it. Good feeling.
Grip is a four letter word.

2 is the new #1.
Jersey Tom
127

Joined: 29 May 2006
Location: Huntersville, NC

0
Jersey Tom wrote:Surprisingly enough the "0.98" part worked flawless and remained almost unchanged every year since I designed it. Good feeling.

Then it's overdesigned .
SZ
0

Joined: 21 May 2007

0
SZ wrote:On the contrary - I've seen championship winning FSAE teams. Good attempts at this problem and those poorer. Some students do do fantastic work, though less stress the important bit: FSAE teams do not race, and as such the life cycle is not comparable. A long way off.

(I'll leave out the other truths that might sound like criticisms, however) FSAE teams might have access to forged wheels but (correct me if I'm wrong) I'm yet to see a team turn out with a custom forged design in an alloy of choice pending their specific needs, which is par for the course in F1.

Consider the fact that most use 4 wheels a year(and wheels are often reused, in our case), to tool up for a custom forging is not necessarily the "smart" decision.....other than that, there are plenty of teams out there that makes custom machined wheel of their own design...and because of stuff being reused, designing them to fail sometimes is also not economical....

As to "racing", how are you defining this? They don't exactly drive leisurely at competition.....We have had parts fatigue enough to fail in competition because we've been testing the car for 1.5 month(subsequently needing to start the practice of replacing suspect parts before comp). There are plenty of parts on the car that will probably be worse for wear after a season(not chassis or actual "hardware", but stuff can be replaced or remade are usually designed to be replaced or remade), which to us is about the useful life of a car(in the case of my cars, ~300 miles a season), so I don't think we are exactly overdesigning a lot of the car....

FSAE teams also don't tend to have a rich brat with racing ambition and daddy with deep pocket to pay for broken, one-off parts, so they don't exactly enjoy the economic leeway of "real" racing neither....
RacingManiac
4

Joined: 22 Nov 2004

0
I´m trying not to offend anyone ,but FSAE is not even almost the holy grail of motorsport,
it is the starting point for students to get into racing. The mountain to climb is still ahead.
marcush.
102

Joined: 9 Mar 2004

0
marcush. wrote:I´m trying not to offend anyone ,but FSAE is not even almost the holy grail of motorsport,
it is the starting point for students to get into racing. The mountain to climb is still ahead.

No, but it has more "design" than most cars running in series below the top level LMP and F1. Since most turn key cars for single make series needs not to push envelope to excel, because you are not competing with the car, instead you are doing it with drivers. And there are little other place that you are building a new car every year...and it probably the ONLY series that has an almost entirely open rule book....active suspension, movable aero(not fan car, lol), traction control, ABS, complex engine control, nothing is off limit.....and everything has been done....

yes its still build by students, and yes the students still only run these in autoX, but the knowhow and knowledge acquired at this level is everybit as valid in other field....
RacingManiac
4

Joined: 22 Nov 2004

0
What happens if you spray them with this?

http://www.vortexsprayliner.com/index.php
Conceptual
0

Joined: 15 Nov 2007

0
Conceptual wrote:What happens if you spray them with this?

http://www.vortexsprayliner.com/index.php

if you do it right they will look better.
you will also add, I think, unnecessary mass.
noname
3

Joined: 13 Feb 2009
Location: EU

0
noname wrote:
Conceptual wrote:What happens if you spray them with this?

http://www.vortexsprayliner.com/index.php

if you do it right they will look better.
you will also add, I think, unnecessary mass.

I wonder as to the strengthening aspect as well.

If you watch the "brick drop" video, they throw a cinder block off a 6 story parking garage, and it bounces when it lands.

Comparing that to an unsprayed cinder block that crushes from a 6 foot height (on their demo DVD, not on their website) I think that it adds an enormous amount of impact resistance.
Conceptual
0

Joined: 15 Nov 2007

PreviousNext