Carbon fibre on cars seems so much cheaper today, why?

[liner33]

I've noticed that carbon fibre parts seem so much cheaper nowadays than they used to. clearly a lot are coning out of China.

BMW seem to produce something called CFRP or Carbon Fibre reinforced plastic can someone explain the various processes and why some types seems so much more expensive than others ?

[Frik]

CFRP is the term for the material used to make the parts you identify as carbon fibre. They are plastic/polymer parts containing carbon fibres.

Traditionally CFRP was used because it has a very high stiffness to weight ratio but had to be manufactured by hand which made it expensive. Automation has made this process much cheaper, plus parts that have more cosmetic than functional value do not require such care in lay-up for subsequent layers.

[911hope]

With the exception of structural elements (tubs in certain sports cars), most "Carbon fibre" parts are just add-on marketing features.

If people are silly enough to pay for a carbon fibre mirror cover at £hundreds, they will see these add-ons. Almost pure margin for the manufacturer.

If prices are falling, then perhaps demand/silliness is dropping, or aftermarket marts are competing or showing the real cost.

[anonymous-user]

I've never understood how carbon fibre parts are more expensive than say, glass fibre

[liner33]

911hope said:

With the exception of structural elements (tubs in certain sports cars), most "Carbon fibre" parts are just add-on marketing features.

If people are silly enough to pay for a carbon fibre mirror cover at £hundreds, they will see these add-ons. Almost pure margin for the manufacturer.

If prices are falling, then perhaps demand/silliness is dropping, or aftermarket marts are competing or showing the real cost.

Stuff like that used to hundreds but now you can buy a couple of carbon wing mirror caps for less than £100

[ZedLeg]

economy of scale, as the manufacturing process and technology has been refined they're able to mass produce the products more easily. This brings the price down.

Cheap carbon fibre is be made on a chinese production line like everything else.

[egomeister]

Funkstar De Luxe said:

I've never understood how carbon fibre parts are more expensive than say, glass fibre

Because carbon fibre is more expensive than glass fibre, and carbon parts tend to be made from woven fabrics while glass is often cheaper processes like chopped strand.

[untakenname]

The RX-8 had a carbon fibre propshaft on cars as standard twenty years ago so there's been cheap carbon fibre used for a while now.

Forged (chopped strand) Carbon Fibre seems to be where it's at now for high end cars, some of the parts are now load bearing as well.

[Ninja59]

Most of it is add on tat. Proper structural stuff is super pricey.

Fundamentally you have three options:
1) wet lay up (DIY)
2) Preppreg (most expensive)
3) RTM (mass manufacture)

Number 2 is old school and is still expensive and for me a proper CF. Pagani, F1 teams etc.

Number 3 is gaining ground for mass manufacture

To combine extra complex nature you have plain or twill CF. Most people know twill.

Don't forget as well you can use different fibres and resins to achieve different things or weave other fibres like kevlar into it.

Toray are still I believe world leaders in terms of volume of fibre produced. Other companies like Solvay, Hexcel are other companies producing prepreg (and in some cases RTM) where the fibre is combined with epoxy ready for the end customer to form into a finished item.

RTM has been around since the late 90's. I did my work experience at a factory who were playing with it back then (a company with a factory in Wrexham and Derby now these days)....

I clearly spent a bit too much time with my dad, now retired, but 30 years+ for one of the companies mentioned. He did work testing CF prepreg mostly for Thrust SSC, Porsche, Ferrari, Red Bull etc. through to Boeing and Airbus (including significant military contracts like JSF)

Edited by Ninja59 on Monday 1st August 15:30

[JoeMk1]

This is an interesting video (if you're a geek like me!) showing some of the mass production of CFRP parts for the previous generation BMW 7 Series:

https://www.youtube.com/watch?v=HuoO99oFQYQ

[liner33]

untakenname said:

The RX-8 had a carbon fibre propshaft on cars as standard twenty years ago so there's been cheap carbon fibre used for a while now.

Forged (chopped strand) Carbon Fibre seems to be where it's at now for high end cars, some of the parts are now load bearing as well.

As does the 350z but buy a new one from Nissan and you’d better sit down , I seem to recall they were best part of £2k

[Equus]

egomeister said:

Funkstar De Luxe said:

I've never understood how carbon fibre parts are more expensive than say, glass fibre

Because carbon fibre is more expensive than glass fibre, and carbon parts tend to be made from woven fabrics while glass is often cheaper processes like chopped strand.

Also, carbon fibre tends to use epoxy resins (it's not worth using an expensive, high-spec fibre with a cheap, low-spec resin) whereas GRP usually uses much cheaper polyester resin.

[kambites]

I'd imagine the reason non-structural CFRP parts have come down in price is that there's more applications across various industries for structural CFRP, meaning that offcuts of CF matting are far more common and hence cheap.