# All carbon composite EV Wheels



## pickmeup (May 8, 2018)

Not sure how many people will be interested but this is what I do as a day job! I'm currently developing this and some other smaller wheels for EV's.

Be good to have a discussion about light-weighting of EV's as adding battery packs to small vehicles usually adds a bit of mass, but you do get to mess around with CofG and weight distribution.

All-composite EV wheel moves to next development phase


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## brian_ (Feb 7, 2017)

It's strange to see a composite wheel looking like a basic stamped steel disc wheel, but it probably makes sense for ease of production and for the intended application. Stiffness under axial loading looks like an issue (like any disc wheel), but I'm sure that has been addressed and the intended applications wouldn't involve high cornering acceleration.

I hope the project hits its cost targets - composite wheels in the high performance world are insanely expensive, so it will be quite an achievement to make these at all competitive with conventional alloy wheels.


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## pickmeup (May 8, 2018)

Hi Brian
We have machined a couple of them to look more like the old school pepperpot steel wheels we all know and love, plus it takes a fair bit more weight out of them too.

Yes the axial loading and impact requirements are all taken into consideration, the wheel in the photo is a 15" but the latest wheel will be a 13" to suit the gordon murray vehicle (unfortunately not T50).

We should be able to meet the target cost, its my main job to try and get as much actuation and automation into the process to reduce costs and maintain quality. Will give an update on here as we progress.


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## brian_ (Feb 7, 2017)

pickmeup said:


> We have machined a couple of them to look more like the old school pepperpot steel wheels we all know and love, plus it takes a fair bit more weight out of them too.


I had never heard the term "pepper pot wheels", but it appears that they are exactly what I imagined when I read it. I suspect that it's a British term - even an actual tabletop dispenser for pepper is called a "shaker" here, not a pepper pot. 

My only concern with machining wheel centres is that the resulting web isn't really optimal - in steel wheels those holes are at least usually (but not always) stamped with a flange, which of course you can't have in composite unless you mould them that way. Of course you'll keep the holes small enough that strength isn't a problem.



pickmeup said:


> ... the wheel in the photo is a 15" but the latest wheel will be a 13" to suit the gordon murray vehicle (unfortunately not T50).


That certainly is specialized - I doubt that there has been a normal highway service car (rather than low-speed vehicle) with wheels as small as 13" for a decade or more... even 14" is probably gone. Composite wheels for a T.50 would probably cost as much as the entire MOTIV "pod"... and strangely the 19" and 20" T.50 wheels are not carbon-fibre because Murray says that wouldn't save enough weight to be worthwhile.


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## pickmeup (May 8, 2018)

Gordon actually said on camera he thinks carbon wheels are "dodgy"
Not ideal for us but I will see if we can get a set on a t50 for show


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## remy_martian (Feb 4, 2019)

My early 60's Ford Falcon (North American made) had 13's and 4 lugs.

Why are you doing epoxy pumps when prepreg gives repeatable results and an ideal resin/fiber ratio?


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## LVVTA (Mar 17, 2011)

The writing on the rim says 3.3kg. A Honda Insight 14" alloy wheel weighs 4.3kg so not much of a weight saving. I assume the cost of a carbon rim will be much more than alloy.
The Insight wheel is a flat disc that should also be better aerodynamically, and a carbon wheel would be less forgiving of kerbing wouldn't it?
Is there any data around this comment: "This puts it firmly on track to reduce the weight of, for example, a 15-inch wheel by 50%, which would deliver 5% fuel savings or a 5% CO2 reduction when retrofitted to a petrol- or diesel-fueled vehicle."
Dan


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## pickmeup (May 8, 2018)

remy_martian said:


> My early 60's Ford Falcon (North American made) had 13's and 4 lugs.
> 
> Why are you doing epoxy pumps when prepreg gives repeatable results and an ideal resin/fiber ratio?


Its mainly down to cost as preg is a lot more expensive compared to dry fibre and resin, plus with our layups we use lots of different materials like Biax-Triax and UD so the costs of pregging it would be crazy.

We get a good Vf from using RTM and as its closed mouds we have a good quality and consistency of the product.


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## pickmeup (May 8, 2018)

LVVTA said:


> The writing on the rim says 3.3kg. A Honda Insight 14" alloy wheel weighs 4.3kg so not much of a weight saving. I assume the cost of a carbon rim will be much more than alloy.
> The Insight wheel is a flat disc that should also be better aerodynamically, and a carbon wheel would be less forgiving of kerbing wouldn't it?
> Is there any data around this comment: "This puts it firmly on track to reduce the weight of, for example, a 15-inch wheel by 50%, which would deliver 5% fuel savings or a 5% CO2 reduction when retrofitted to a petrol- or diesel-fueled vehicle."
> Dan


Yeah its not compared to an alloy rim, its compared to standard pressed steel wheels. I can certainly tell you the weight saving is more than 50% compared to the steel wheel.

Kerbing is factored into the design and the testing of the wheels, we cant show any of it, but there are a few companies around now selling carbon wheels. The leader is CarbonRev in Oz.


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## brian_ (Feb 7, 2017)

remy_martian said:


> My early 60's Ford Falcon (North American made) had 13's and 4 lugs.


Yes, wheel sizes have gone up substantially since the little-wheel era, when even a full-size 3-ton car had only 15" wheels. Wheels don't need to be as big as they typically are now... but that's what the market demands, so by today's standards 13" is tiny.


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