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Carbon fibre production wheels


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#1 mariner

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Posted 11 July 2015 - 09:56

I can remeber that long,long ago Citroen tried CF wheels but it didn't seem to get anywhere.

 

Now Ford has released them on the Shelby Mustang.

 

http://www.autoblog....n-fiber-wheels/

 

There may be a snag but I'm a lot more confident on CF whels now major OEM  has decided to sell them.

 

The benefits sound impressive, as they are Australian sourced maybe Greg might know something more (please) ?



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#2 MatsNorway

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Posted 11 July 2015 - 11:55

Citroeng had Glassfiber wheels i believe was the conclusion here last time it got brought up.

 

Anyway. This is so cool. I really like that this comes from a OEM. Also it being more mass produced could open the gates for the rest to follow and lower the prices quite a bit.


Edited by MatsNorway, 11 July 2015 - 11:56.


#3 Greg Locock

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Posted 11 July 2015 - 13:23

It so happens that one of my friends who came round for dinner tonight is the production engineer at carbon revolution, and two people I have worked with are cofounders... So, waderyerwannaknow?

http://www.carbonrev.com/

#4 Greg Locock

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Posted 11 July 2015 - 13:30

Incidentally our conversation was more about how you get a hand layup through quality control than any fancy pants discussion of handling etc.

#5 MatsNorway

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Posted 11 July 2015 - 17:03

You video/photo the production process. One picture every 5 sec or something. Manually operated start/stop of the documentation prosess. Or/and you can make a spesific order of the pieces. Light the spot up and the operator puts the weave there. When done he can punch a button and a picture is taken. Then he recieves the new patches from the robot. No reason to make them individually every. single. time.

 

How likely is this prosess to be done by machines in the future?

 

Im imagining a machine sticking a carbon thread through a porous material until you have a solid carbon weave. To get rid of the porous prosess you can for instance dip it in fluid or heat it.


Edited by MatsNorway, 13 July 2015 - 08:20.


#6 imaginesix

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Posted 11 July 2015 - 18:38

Is there a special tire mounting procedure required? Standard machines would risk damaging these wheels I'm sure.



#7 mariner

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Posted 11 July 2015 - 19:22

One question, the actual wheel design seems , superfically, to be identical to a cast wheel which has  no opportunity for optimising strength through changes in ply direction, frequency etc.

 

Is the detail fabrication via the lay up more complex than it seems?

 

OR maybe the design of wheels is so refined you wouldnt be able to anything new?



#8 Greg Locock

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Posted 12 July 2015 - 01:17

Mariner-no the design is optimized in FEA - Both in shape and fibre orientation. The trickiest part is the hub, I suspect it is one area where aluminum is just as good, carbon tow being great for spokes etc, but has a problem when the loads can be in any direction.

I'll ask about the rest, yes some sort of robotic help is an obvious future step, given the production engineer's background I imagine the whole assembly operation will get the usual Japanese style process improvement. I know he's done the first bit and actually worked out where they are, now the fun starts.

#9 MattPete

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Posted 12 July 2015 - 02:08

I seem to remember a company advertising carbon/graphic/fiberglass (some kind of composite) racing wheels in the back of the SCCA rule books.  This would have been around 1990 (±2 years).



#10 mariner

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Posted 12 July 2015 - 19:47

I would assume that finding a resin system capable of retaining strengh with a brake rotor virtually glowing centimetres from it is small challenge - or maybe on a road car some sort of radiant heat shield is used?


Edited by mariner, 12 July 2015 - 19:47.


#11 MatsNorway

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Posted 12 July 2015 - 20:02

Thermal spray is old tech. And the Ford has it on their rims. But i believe the Koenigsegg does not.



#12 imaginesix

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Posted 12 July 2015 - 20:15

Thermal spray is old tech. And the Ford has it on their rims. But i believe the Koenigsegg does not.

Actually it's applied mostly to the hub and spokes, not so much the rim of the wheel.

 

"Using a plasma arc gun to liquefy a ceramic material, the wheels are coated at critical points around the inner wheel "barrel" and on the back of the spokes."


Edited by imaginesix, 12 July 2015 - 20:16.


#13 Chubby_Deuce

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Posted 12 July 2015 - 23:09

 

How likely is this prosess to be done by machines in the future?

 

Bicycles are slowly getting there. http://www.bikerumor...n-construction/



#14 bigleagueslider

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Posted 13 July 2015 - 01:43

I have seen problems with pressure tightness using layups of prepreg materials. So I took a look  at Carbon Revolution's website to see if there was any information on the manufacturing process used for these wheels, but I didn't find anything. I did a quick search of patent files to see if there was any relevant IP, and I found this. It appears to describe a RTM process. So I would assume the fiber is placed in the tool dry and likely consists of stitched and woven preforms to expedite the fiber placement process. Silicone bladders/intensifiers are probably used to provide compaction during the resin infusion. However, one major issue with placement of dry fabric as used in typical RTM processes is alignment of the fibers in the cured laminate. The orientation and straightness of fibers is critical to ensure required properties in the cured laminate. A composite laminate produced using RTM is typically less structurally efficient than one produced using autoclaved prepregs, due to the much higher resin content and inferior fiber alignment. So I would question the accuracy of some of the comparisons made on Carbon Revolution's website between their composite product and existing metal products.

 

In regards to claims made in the article linked in the OP about weight savings of these composite wheels vs aluminum wheels, they seem a bit overstated. The article notes a similar aluminum wheel weighs 33 lbs, but in reality a similar high-performance forged monobloc aluminum wheel probably weighs less than 24lbs.



#15 Lee Nicolle

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Posted 14 July 2015 - 03:54

My thoughts are these are like hi mag alloy wheels a potential accident down the track as the carbon deteriates. With heat, constant road shock, and UV forces on them. Five years?

 

I have seen a couple of articles on c/f rims and while there is a significant weight saving it really is about 20-30% over a decent  cast/ forged alloy wheel. Most of that in the critical centrifigual mass which is good. Though in reality how much in comparison to a composite all alloy rim would be interesting. I doubt tyre fitting would be any harder unless you are using tyre levers and a mallet!

 

In the past there was plastic wheels used on Sprinters, they were banned fairly quickly though I do not know why. I never heard of a failure. The only one I saw though was no lighter than a composite right rear which were fairly mainstream even then. I do believe they were cheaper though.

 

One of my sack trucks had plastic wheels which were actually very good but one failed recently. The red wheel had gone pink in the sun :drunk:   It was about 8 years old though!



#16 bigleagueslider

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Posted 15 July 2015 - 04:16

The concept of composite wheels has been around for decades. But one question I have is why aren't composite wheels used on aircraft? Aircraft wheels would seem to be a far more logical application of this concept due to the more favorable weight/cost metrics. Yet most aircraft wheels are still made from magnesium forgings. Why?



#17 Greg Locock

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Posted 15 July 2015 - 07:08

(a) conservatism, NIHS

 

(b) cost benefit analysis, at a guess. How much do aeroplane designers pay for 1 kg saved? For cars we used to have the laughable figure of seven bucks a kilo, when I pointed out that this meant we would have to be able to build a fully functioning car that weighed nothing at all for 28000 dollars which seemed remarkably cheap the program manager turned red and made another little note in his book.



#18 kaydee

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Posted 16 July 2015 - 08:19

Greg, from a practical perspective I wonder how the rim flanges of a carbon fibre wheel stand up to the rigours of fitting of today's low profile tyres?

Is a special tyre changing machine / technique required?

Also, how are the wheel nuts seated.  Flat, tapered or inserted?



#19 Greg Locock

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Posted 16 July 2015 - 08:55

I don't know, I'll ask.

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#20 Brandnelson

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Posted 17 July 2015 - 06:29

FWIW BST has been producing carbon wheels for sportbikes for quite some time. Readily available, significant weight reduction, even over quality mags. Had a chance to try them, made a 1000cc turn in like a bicycle. They were specifically banned in racing when I was involved, I never understood why. I knew a couple guys who had them on their street bikes and had no issues with durability or having any average cycle shop mounting tires. Looked like they were made using RTM, alloy hubs.

#21 Lee Nicolle

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Posted 19 July 2015 - 04:16

Greg, from a practical perspective I wonder how the rim flanges of a carbon fibre wheel stand up to the rigours of fitting of today's low profile tyres?

Is a special tyre changing machine / technique required?

Also, how are the wheel nuts seated.  Flat, tapered or inserted?

From what I have read [in the last year or so] the steel inserts are moulded in the wheel. Normal taper seat alloy nuts were used. Something I personally do not like as I have seen too many gall and not tighten correctly,, or strip out.

I suspect long term the inserts may be suspect too though I am sure they would have worked hard on that problem in design.



#22 IrishMariner

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Posted 08 August 2015 - 23:44

....But one question I have is why aren't composite wheels used on aircraft? ....most aircraft wheels are still made from magnesium forgings. Why?


I've often asked myself the same question and I imagine the chemists at the various materials suppliers are working on a suitable resin/fibre. I would think that heat is probably the biggest reason. Rather than a single disk, airplane wheels house a stack of carbon disks (similar to a racing clutch). The Pistons are arranged all around, too, so there's little room for the hot air/gas to escape except for the radial edge - right into the wheel rim. Lots of thermal energy dumped into the wheel in a brief amount of time.

#23 Lee Nicolle

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Posted 09 August 2015 - 08:04

The concept of composite wheels has been around for decades. But one question I have is why aren't composite wheels used on aircraft? Aircraft wheels would seem to be a far more logical application of this concept due to the more favorable weight/cost metrics. Yet most aircraft wheels are still made from magnesium forgings. Why?

Talking to a  commercial pilot mate today and he seems to think most aircraft wheels are normal aluminium forgings. Though this info is 3rd hand from a guy who drives aeroplanes,  not maintain them. Though it would make sense to me. Stronger and cheaper and a far longer service life for  a small weight premium



#24 bigleagueslider

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Posted 10 August 2015 - 05:22

Not long ago forged aluminum was preferred for most aircraft wheels due to issues with hot strength and corrosion resistance of existing magnesium alloys. But now there are magnesium alloys available that have excellent corrosion resistance and elevated temperature strength comparable to aluminum alloys. If you consider that replacing aluminum with magnesium provides a 1/3 reduction in weight, and the significant weight of the wheels used on a typical aircraft, the choice to use new corrosion resistant magnesium alloys seems obvious.



#25 desmo

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Posted 10 August 2015 - 15:50

CFRP wheels for cars are surely 99% a marketing thing.  I can't imagine a serious engineer or someone doing sober cost/benefit analyses advocating for their adoption. The same money spent on fully optimized steel or Al alloy wheels and/or other less marketable innovations would probably deliver far more actual benefits. 



#26 imaginesix

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Posted 11 August 2015 - 01:36

CFRP wheels for cars are surely 99% a marketing thing.


Kinda like the car itself.

#27 desmo

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Posted 11 August 2015 - 02:47

No. Cars have a purpose: get you from point A to point B. CFRP wheels are really only there to extract money from status seekers. Until they are as cheap as metal wheels and don't prevent you from getting to point B. At that point they won't be just marketing but just another thing you use. Nobody will ever be able to tell the difference riding in a passenger car whether the wheels are metal or CFRP without looking, but people outside the car presumably will. Pure marketing; pure as it gets.



#28 404KF2

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Posted 11 August 2015 - 03:22

CF fails catastrophically when it fatigues or is shocked beyond its design parameters (pothole, anyone?), so I would be surprised if anyone who is halfway sensible would choose these for road use.  Even for CF bicycle frames, you have to inspect them very carefully regularly to make sure they're not about to let go.



#29 Greg Locock

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Posted 11 August 2015 - 05:50

Gosh I wonder if they thought of that, given that they are OEM fitment?



#30 Canuck

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Posted 11 August 2015 - 14:02

At a guess, I could see a decrease in acceleration times as there's less rotating mass to spin up at all 4 corners. Given that we're talking 7-figure cars here to begin with - which are more about engineering exercises than anything to do with usefulness or practicality, I think it fits perfectly.

#31 desmo

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Posted 11 August 2015 - 14:55

It is claimed that the composite wheels are 18 lbs. each and the super high end alternative metal wheels are 33 lbs.  This is  far beyond the weight reductions typically seen in this material substitution.  Can someone confirm these weights?  In spite of my cynical tone above, if the figures given are correct, that's significant and if the price can be got down somehow to be competitive with high end metal wheels, then this does represent a real advance.  I'm actually much more skeptical these can ever be cost competitive than that they are are a significant engineering development. But if they cost multiples of the best alternatives, they will forever be a real world irrelevancy.



#32 gruntguru

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Posted 11 August 2015 - 22:00

The factor is something less than 2:1 ie if the weight reduction is entirely at the perimeter of the wheel (tyre) the effective mass being accelerated is reduced by double the actual weight saved. Obviously wheel rims at a reduced radius are somewhat less - say 1.6? that would make Desmo's example of 15 lbs saving a total of 15 x 4 x 1.6 = 96 lbs. That would definitely show up in acceleration times.



#33 Greg Locock

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Posted 12 August 2015 - 00:49

According to this rather detailed looking tool a 21" rim would weigh 21 kg. http://www.wheel-siz...l=30mm&scl=50mm

 

That seems high to me, it may be a gravity cast aluminium/air alloy  rather than a low pressure die cast aluminium wheel. That's a little joke, porosity is a big problem with gravity cast wheels


Edited by Greg Locock, 12 August 2015 - 00:50.


#34 imaginesix

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Posted 14 August 2015 - 23:05

No. Cars have a purpose: get you from point A to point B. CFRP wheels are really only there to extract money from status seekers. Until they are as cheap as metal wheels and don't prevent you from getting to point B. At that point they won't be just marketing but just another thing you use. Nobody will ever be able to tell the difference riding in a passenger car whether the wheels are metal or CFRP without looking, but people outside the car presumably will. Pure marketing; pure as it gets.

Because a Fiesta can't get people from point A to point B, we need a Mustang Shelby GT350R.

#35 404KF2

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Posted 15 August 2015 - 06:36

Gosh I wonder if they thought of that, given that they are OEM fitment?

 

Oh probably, for the three year life cycle that matters to manufacturers.  Then what?  I wonder what the annual "wheel inspection fee" will be at the regular service  :drunk:



#36 imaginesix

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Posted 15 August 2015 - 15:43

Oh probably, for the three year life cycle that matters to manufacturers.  Then what?  I wonder what the annual "wheel inspection fee" will be at the regular service  :drunk:

If your cars always fall apart after three years, maybe for your next set of wheels you should consider those that aren't made in France.

#37 bigleagueslider

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Posted 16 August 2015 - 06:05

For the typical driver, abrasive damage to the outer edge of a wheel rim is a common occurance due to contact with curbs when parking. Especially with low profile tires. Abrasive damage to a composite structure surface can be a problem, since it will allow moisture and contaminants to infiltrate into the laminate. Replacing one of these composite wheels will likely cost $4-5K.



#38 kikiturbo2

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Posted 16 August 2015 - 13:52

I recently witnessed a $3K+ rear bicycle wheel rim break due to a relatively minor impact into a street tram rail.. Needles to say the rim is not replacable, being glued to spokes and hub, so it is a total loss..

 

One other interesting aspect is that some manufacturers used alu wheels that would deliberately buckle on potholes (audi rs6) to save the suspension components.. this is something that cant be done with CF..



#39 Canuck

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Posted 16 August 2015 - 15:46

I would hazard a guess that not many "typical drivers" will own the 350R. With AC and entertainment package deleted by selecting the R option, it doesn't sound like the $65,000 typical driver's choice. Even still, I would imagine these will show up on the street.

My question is so what? So what if curb rash is really effing expensive to address? So what if the wheels are outrageously expensive? So what if it's all marketing? It's still the cheapest car you can buy on which you can have carbon fibre rims, which are without much argument, the lightest wheels you can own and by a significant margin. Others would be suited to examine the potential benefits of reduced wheel weight beyond being able accelerate them faster. Regardless, the entire notion of a 500+hp car eclipses "basic transportation" a long time ago. A city bus, a bicycle, a SMART car, hell, even a pickup - these are useful transportation vehicles. The 350R, without a rear seat, without AC, with a "track-oriented chassis" - this is not transportation. This is go-fast car, a toy, an engineering exercise where ideas like plastic wheels for perhaps marginal / perhaps real-world returns makes absolute and complete sense. I don't get all the naysayers, especially in this, the technical forum.

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#40 BRG

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Posted 16 August 2015 - 18:18

So you are proposing CF wheels as a fashion statement, rather than as a technological advance?



#41 Canuck

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Posted 17 August 2015 - 00:50

No. I'm suggesting that the mass-market issues presented here have little to do with a limited edition track car. Nobody, it would appear, is saying there's no benefit, only one of disputed value. I'm saying on $65k toy, from the perspective of curb rash and potholes, the entire thing is of limited value.

#42 desmo

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Posted 17 August 2015 - 02:09

One good thing: they are F1 illegal.  Hot street cars should by default attempt to break every every performance limiting rule in the F1 technical regs, if not all technical regs everywhere  If your car would be legal to race anywhere with the usual mods, you just aren't trying hard enough.



#43 Greg Locock

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Posted 17 August 2015 - 04:21

Grins, I think I will call that Desmo's Law of Perversity. Surely everybody knows that F1 is the pinnacle of technological achievement and all other fields merely trudge in its wake.



#44 saudoso

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Posted 17 August 2015 - 10:41

Well, I'm getting old I and suspect the snoring is affecting my memory, but I seem to remember the same being said about aluminium in mass production cars. And bicycles and motorcycles while at that.


Edited by saudoso, 17 August 2015 - 10:42.


#45 Canuck

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Posted 17 August 2015 - 12:30

They also have fenders, doors and glass - all F1 illegal.

I don't know all of the regs in all of the global racing series (shocking I know), but I suspect a very good many of our more advanced "factory hotrods" aren't race legal in most, if any. The advent of traction, launch and stability control alone puts them out of F1, as do their oversized V8s and V10s, their variable valvetrains, flapper exhaust and variable geometry intake. Not to mention the electronically controlled differentials and all-wheel drive systems.

I know we used to debate that F1 was losing relevance to the street cars and whether that mattered, but you seem to be arguing the opposite.

#46 bigleagueslider

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Posted 22 August 2015 - 09:03

Grins, I think I will call that Desmo's Law of Perversity. Surely everybody knows that F1 is the pinnacle of technological achievement and all other fields merely trudge in its wake.

 

F1 cars do make good use of the latest and greatest technologies in materials, electronics, controls, etc. But none of these technologies originate in F1. They come from aerospace and commercial automotive. CRC brakes came from the defense industry. CFRP composite structures and materials came from the aerospace industry. The digital analysis and design tools came from the defense and aerospace industries.



#47 MatsNorway

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Posted 22 August 2015 - 20:59

BigL

 

That is a silly sentiment i see around here far too often. Also i believe the irony is missed.

 

nearly every technology used in motorsport started somewhere else as you stated. Why? because they usage was simply not suited, competitive or legal in F1 yet at the time of their conception. The same may often be true for aerospace industries. If you go back far enough you often find a scientist or a matematician. Was Thomas Edison the father of Carbon fiber perhaps? https://en.wikipedia..._fibers#History

 

F1 cars is the pinnacle of motorsport within their rules. And it is thus fairly meaningless to compare to others with other strange limitations.

 

We should instead compare F1 with itself. And discuss its purpose. Has FIA gone mad or have they not?

 

I would suggest starting the discussion with what Grand Prix racing set out to do.

 

Fastest driver in the fastest car maybe?

 

If you bring the counter argument that they would then be too fast and too violent for any driver to push to the limits i would suggest to simplify the rules and the materials allowed. To allow a bigger and more competitive field for a lower cost.

They have simplified the materials as highly toxic materials have been used in the past. But I feel their direction in general is poor and fairly random.


Edited by MatsNorway, 22 August 2015 - 21:01.


#48 imaginesix

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Posted 22 August 2015 - 23:10

F1 has been the stepping stone for some technology ahead of its application in road cars. It doesn't matter if the technologies were invented by F1, that's not the point. It still furthered their development and accelerated their deployment 'downstream'. That's really all anyone ever really does, as mats suggested. An inventor is the one who happens to find improvements that are distinct enough to give a technology a new name. Like seat belts that existed as harnesses before, they were just applied to restrain someone to a seat and voila, a brilliant new technology! Within the automotive sector F1 has pioneered many technologies and that's all people rightly credit it for.

#49 Greg Locock

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Posted 23 August 2015 - 09:27

I suspect the list is short, if you mean technologies that were used positively (as opposed to randomly) in F1 before being used in production cars or other race series. One of the sad things about innovation in automotive is that 80% of it was patented before 1920, usually by Lanchester.

 

Meanwhile, I asked the carbon wheel people about tire fitting - yes there is no issue using standard techniques although undoubtedly a gorilla with a breaker bar could damage the paint. The wheels themselves are tough and impact resistant and meet OEM requirements for square edge pothole etc, but they haven't found a paint/clearcoat system that is as robust as on alloys. It's being worked on.



#50 MatsNorway

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Posted 23 August 2015 - 10:11

You want X amount of mm of termal sprayed metal on that contact surface.

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