rim is brake heatsink?

[normality78]

heard about plp saying that be4? well here u go....

"Your braking efficiency improves with the light alloy rims. Efficient
braking depends on how much heat it can dispose off via the rims (rims is
the heat sink). The brake pads is less efficient of the heat is too high.
Getting rid of this heat is the answer. Of course, rigid brake lines
helps in getting that feeling of good grip, but treat the root cause first,
that is a good alloy rims. Keep it as light as possible, stick with 14".


http://www.autoworld.com.my/forum/allposts.asp?summary=1&Forum=ap111582596&access=1&status=1&Subject=AE111+upgrades%21%21%21%21&Closed=&page=4


its either me dumbass or......

 

[msafiedin]

i agree
thats why the pattern of the ori japan made
is made in such way that
when u brake it will dissipate
through the holes (pattern) of the rim
my theory lor
but thought about this long time ago
but never got chance to share

 

[normality78]

disperse heat thru those "hole" is 1 thing. act as a heatsink is 1 thing. don't u think its 2 diff thing?

 

[zan]

a wheel and a tyre is part of a car that is called unsprung weight.
unsprung weight really affects a car performance because of its genuine weight.

it will also affect braking performance because of added momentum in it.

proton waja original alloy wheel does not look good in terms of dispersing brake heat but the brake does work properly no matter how hard we use the brakes.

 

[normality78]

a wheel and a tyre is part of a car that is called unsprung weight.
unsprung weight really affects a car performance because of its genuine weight.

it will also affect braking performance because of added momentum in it.

this part i do agreed.

proton waja original alloy wheel does not look good in terms of dispersing brake heat but the brake does work properly no matter how hard we use the brakes.

but how does this related with rim itself IS a heatsink?

 

[prodigy]

Rims are not heatsink. Period.

They certainly help to disperse some heat but its function is certainly not as a heatsink. You wanna know whats a heatsink, open up your computer and you see the thing on top of your processor. Or quite simply, your car radiator which main function is to remove heat.

With our day to day cars, there's absolute no reason for you to consider heat dissipation from rims when you're at a tyre shop choosing rims. Just buy the one that is light and looks good. That would help so much more. But of coz when saying that, those bling bling shiny rims that encloses the whole brake disc is a different matter altogether. It may not dissipate heat better than usual but its not a big problem either. If your car is a city driving car, braking efficiency when using another other rims is not a problem.

And yes, unsprung weight is something most people fail to look at. The reason why Taiwan rims at times are far inferior over original Japan ones for instance, Volks Racing, is the weight. Unsprung weight on rims increases the momentum of a travelling car and will take a bit more effort to brake. You don't see track drivers using big ass 19" or 20" rims for their race car although technically it offers bigger contact patch over 15" or 16". Another reason is also because of the friction coefficient. The bigger the tyre contact patch, the more friction is produces.

 

[si|verfish]

LOL...heatsink???

Well, I'm not sure there is much thermal conduct from the brakes to your rims, if at all. Inefficient thermal transfer is a no no if you want to use something as a heatsink. Your alloys are normally not in good contact with a great area of the brakes and they aren't very good material at conducting heat. Plus they don't have a very wide surface area, relatively, to dissipate the heat it absorbs (again, if any). So this myth (or should I say bullshit) is busted.

However, you can probably design your alloy wheels in such a way that it helps the flow of cool air to the brakes or hot air away from it.

Otherwise, the way alloy wheels improve your car's performance is if it is lighter therefore reducing unsprung weight, as have been said above by other posters.

 

[TiBuN]

However, you can probably design your alloy wheels in such a way that it helps the flow of cool air to the brakes or hot air away from it.

I would think this is valid, good / expensive rims (e.g. some japanese rims) are having minor ventilation functions, hence able to dissipate heat, but not act as a heat sink.
But I would further say that this only applies in high speed.

Another reason of good rims design is it can compliment the diffuser effect and create a low pressure beneath the car, hence increase traction at high speed.

 

[SkYwAlKeR]

proton did try their hands on such rims rite??... for example the SNeo.... they have fan-blade rims to draw cool air into the disc when the rims is turning... hahaha...

 

[netmatrix]

Wheels are heatsink? hahaha. Not likely. The metals used are not very conductive for heat transfer. There are some heat transfered from the disk to the wheels. But they are quite minimum. Most of the heat is dissipated from the disc itself. Hence the ventilated type. Anyway even if the wheels are made of full aluminum, the painted surface would deter heat from being transfered out.

 

[alexklg]

definitely rims can't efficiently dissipate heat. Only the flowing of air promotes cooling of brakes. that's why some bumpers have side vents to direct some flow over the brakes.

hehe... the SNEO rims are rubbish. Changed to a ultralight weight taiwan rims. So much lighter that the stock rims (at least 50% lighter). The response is noticable.

 

[sam1741]

i thinking a bit contradict... between 'hole' and 'heatsink'

from my experience...
heatsink = to desipate heat
the larger surface of heatsink, the easier it loose heat

but hole...
the larger the hole on your rim
the cooler your disc can be.. cause air outside can come in n cool the brake..

 

[bobo]

i don think its a heatsink.. its just for better ventelation so ur brake wont over heat..

 

[BlackSamurai]

i never notice i have 17" heatsink installed. LOL

better install this

http://www.f1technical.net/articles/mech/images/brake.jpg
copyrights of McLaren F1

 

[tajulsans]

I wanna DIY install some copper fin on my VR rims and also add a cooling fan to improve my braking further.. no point upgrading to Mintex M1144.. huhuhuhu

 

[Lennon]

I dont think rims act as a heatsink. But for those who have forged rims such as Volks, you can really feel the heat. Rims doesnt design as heatsink but it in directly helps to distribute some heat from the rotor......

If rims works as heatsink, i need to change my tyres everyday..... :_:

 

[prodigy]

hehe... the SNEO rims are rubbish. Changed to a ultralight weight taiwan rims. So much lighter that the stock rims (at least 50% lighter). The response is noticable.

I'm a bit sceptical about ultra lightweight Taiwan rims. Most of the Taiwan rims i see in tyre shops are pretty heavy and if there is a lightweight one, i'm just worried it can't take the bashing from our famous pothole roads. I'd rather pay more for a ultra lightweight Japanese rims whereby i'll feel secured when driving over potholes. I'm not saying the Japanese ones won't break too but at times, i question Taiwanese goods.

 

[Dino@Casper]

i'm quite sure rims are not heatsinks, at least thats what i believe i have learn in heat transfer.. exactly how much cooling effect does a rim have i'm not to sure..

 

[prodigy]

Besides, alloy or steel rims are not exactly the best heat reliever.

Unless your rims are made of copper. Then it would be super soft. Besides, you'll need to change tyres every 2 weeks.

 

[ken12292703]

If it acts like a heat sink, then we must apply thermal paste at the contact point... How many tubes we need to buy??? Akakaka... Joking joking...

I think rims are not heat sinks lerr, they just serve a purpose that's holding the tyre and stick on the road...