Heatsinks on disc brakes

Kiblams

Two of my main hobbies are computing and MTB (and the maintenance/building of each)and I was reading an article about a giant bike on todays Bikeradar and spotted that the new Shimano XTR brakes have pads with heatsinks :shock:

Good to see technologies beign used across from one to the other, how long before my PC has cranks on the side of it?

NatoED

nolan made a fork with a computer controled system . even had a mirco proccessor in the legs. needless to say it broke alot . that was in 97/98.

P-Jay

Yeah I spotted the cooling fins on the new XTR stuff, practical or marketing BS?

Thought, if anything you'd see this sort of thing on the Saint DH brakes, rather than XTR even the new more 'trail' baised versions aren't exacty the sort of thing you expect to see with smoke coming of the rotors coming down a steep mountain.

anton1r

NatoED wrote:

nolan made a fork with a computer controled system . even had a mirco proccessor in the legs. needless to say it broke alot . that was in 97/98.

Aren't Cannondale up to something pretty similar at the minute?
*EDIT*
Here's the link..
http://www.cannondale.com/none/none/simon

NatoED

yeah but the nolan was fully sealed up in the leg with a perspex cover . to tune it you had to take out the curcuit board and plug it into your pc via the midi or com1 port. it would brake becuse of the perspex cover causing condensation to interfear with the eletronics and they couldn't isolate the bump forces from the system so it would bounce apart. it's a nice idea but knowing cannondale they will mess it up too.

Anonymous

Heatsinks aren't an inherently PC based phenomenon though.

As for the XTs, my guess is that they're trying to make them as light as possible, which means as little material as possible, to to handle the that they give it a heat sink to increase surface area without increasing mass too much.
Don't know for certain though.

Kiblams

The description in the article suggests that the heatsinks themselves are actually on the pads, so maybe it's a way of charging above the odds for pads? (call me a cynic )

Anonymous

hmm, you could be right.
Or still, there's a possibility that the callipers are made so small and light that they'd struggle otherwise.
I remain pessimistically optimistic about it.

Kiblams

I suppose if I were feeling optimistic I could see where they might be reducing the amount of fluid that is needed in the caliper (possibly there to aid in keeping the heat down) and this cuts down on weight?

jayson

Kiblams wrote:

The description in the article suggests that the heatsinks themselves are actually on the pads, so maybe it's a way of charging above the odds for pads? (call me a cynic )

+1 this, it is shimano we're talking about afta all.

Anonymous

You're kidding me, right? :roll:
You think shimano is overpriced compared to who exactly, Hope? Crank Brothers, Salsa? Campag?
Gimme a break.

Lapierre t 400

I think its just an easy way of charging people more for a set of brake pads
but that computer controlled lefty fork was amazing,can't imagine how much its going to cost or how often it will break

FunBus

the new XTR pads are pretty cool. The cooling "fins" are only on the all mountain version where weight isnt quite so crucial as on XC racers. They are made of alloy to help dissipate heat quicker and are intended to draw cooler air into the system helping to keep running tempretures lower and performance higher. They are part of the pad (as mentioned above) but this is simply down to what they are for - if they werent attached to the pad, how could they help cool them?

The new rotors also have an alloy section in the middle to help kick out the unwanted heat.

It's all about staying cool.

And as for being over priced, if you're buying XTR, you're quite clearly not penny pinching so who cares!!

Northwind

Can you remove the heatsinks and refit them with a better thermal compound? Then overclock your brakes?

Kiblams

FunBus wrote:

if they werent attached to the pad, how could they help cool them?

By being in direct contact with the brake fluid and cooling that

I think Northwind has the right idea!

MrChuck

jayson wrote:

Kiblams wrote:

The description in the article suggests that the heatsinks themselves are actually on the pads, so maybe it's a way of charging above the odds for pads? (call me a cynic )

+1 this, it is shimano we're talking about afta all.

Wait, you mean- Shimano are only in business to make money? And they only bring out new things to increase their sales, and add new features so they can charge more for them?

Crikey.

FunBus

And how do you suppose you could put it in direct contact to the fluid to have a positive affect?............all whilst the standard pads are still heating up a lot faster and transferring the heat through to the fluid

Or are you two just pulling my chain?

BenS999

Can you remove the heatsinks and refit them with a better thermal compound? Then overclock your brakes?

Only the Quad Core's

Kiblams

FunBus wrote:

And how do you suppose you could put it in direct contact to the fluid to have a positive affect?............all whilst the standard pads are still heating up a lot faster and transferring the heat through to the fluid

Or are you two just pulling my chain?

No I was being serious; the quicker you can remove heat from the fluid, the quicker it will transfer from the pads into the fluid and out of the heatsinks. Think of water cooling in PCs.

EDIT: Thread name changed to reflect discussion

biff55

i call marketing BS.
heat sink ? the calipers are already exposed to free air on all sides , pointless.

FunBus

Hmm, i see your point (even though i dont have a clue about water cooling in PC's).

My only logic was, if you keep the rotor and pads as cool as possible, less heat will transfer into the fluid to begin with. The rotor and pad are the hottest part of a disc brake system, so cooling them would have an improved affect on the performance. It would be difficult to add something to cool the fluid itself as it doesnt really "flow" around the entire system.

As for the caliper having cool air touching it on all sides, yes it does, but not in the centre, where all the heat is created. When i first saw these i thought they were marketing BS, but now i'm not so sure.

Granted, this could be seen as development for developments sake, but either way, they have been reported to be pretty good....

chedabob

Pinkbike review said they were pretty good. You can buy pads without the heatsinks, and no doubt third-party pads will come with heatsinks.

That Cannondale fork didn't impress me very much. It just sounds like a Lefty with a motor on the rebound adjuster. I want Bose's Active Suspension on my bike

cavegiant

My thoughts on this are simple, but most of my thoughts are.

The heatsink on most brakes is the disk.
The disk is rotating weight (just).
XTR are transferring a bit of rotating weight to a bit of static weight.

It seems a great idea to me, you are also cooling the pad from both sides.

The fact that they can now charge a lot more for pads, and have a reason for people to come back from OEM pad sales (as this will be copyright) is a complete coincidence ;-)

supersonic

I guess some mag, like WMB did, will stick them on a dyno and measure temps and cooling.

Radioactiveman

Be interesting to see how much a new set of pads cost

nicklouse

Kiblams wrote:

Two of my main hobbies are computing and MTB (and the maintenance/building of each)and I was reading an article about a giant bike on todays Bikeradar and spotted that the new Shimano XTR brakes have pads with heatsinks :shock:

Good to see technologies beign used across from one to the other, how long before my PC has cranks on the side of it?

only on the AM version. the XC ones dont have them.

Andy B

Cube have designed an active cooling system for the rear disc brake on the Elite Super HPC hardtail (frame weighs in @ 950g!)



No idea how effective it is, but it's a nice idea

The typo will be corrected on production models

neddie

i call marketing BS.
heat sink ? the calipers are already exposed to free air on all sides , pointless.

+1 from me too

chedabob

neddie wrote:

i call marketing BS.
heat sink ? the calipers are already exposed to free air on all sides , pointless.

+1 from me too

Increased surface area...

NatoED

surly a cooling duct on the calliper would be better (like in F1) or over the disc itself . Would having a greater amount of fluid in th ecalliper help with cooling? or a cuircit you could pump fresh fluid around your system while braking. Two hoses with a non return valve that worked when the brake lever is released sucking new fluid through the calliper ?