H2O Brakes

S

schred

Likes Bikes and Dirt
Fark, water-based brakes, in a closed system. Such a sh1t idea, whoever came up with that should be forced to use them.

Maybe they are just quick off the mark for april fools' in 3mths time.

EDIT:
See data below for fluid boiling points, water is so far down the list it can't be anything more than a joke.

ARRANGED BY DRY BOILING POINT:

Water
DRY: N/A -- WET- 212F

Shimano Mineral oil
DRY: 536--WET: N/A - #'s provided by Shimano, who claim no moisture absorption

DOT fluid:

DRY:401F -- WET:284F --- DOT3 MINIMUM (GLYCOL BASE)
DRY:446F -- WET:311F --- DOT4 MINIMUM (GLYCOL BASE)
DRY:500F -- WET:356F --- DOT5 MINIMUM (SILICONE BASE)
DRY:500F -- WET:356F --- DOT5.1 MINIMUM (GLYCOL BASE)
DRY:500F -- WET:???F --- FORD HEAVY DUTY DOT 3 PM-1C (new since 2006)
DRY:527F -- WET:302F --- AP RACING 551 ($12.799/0.5L OR 16.9 OZ)
DRY:527F -- WET:347F --- VALVOLINE SYNPOWER DOT3 & DOT4
DRY:536F -- WET:388F --- ATE SUPERBLUE/TYP200 ($9.95/1L)
DRY:550F -- WET:284F --- FORD HEAVY DUTY DOT 3 PM-1 (pre 2006) ($4/12 OZ)
DRY:570F -- WET:284F --- WILWOOD 570 ($5.65/12 OZ)
DRY:570F -- WET:284F --- PERFORMANCE Friction Z rated ($6.27/16 OZ)
DRY:572F -- WET:410F --- AP RACING 600 ($21.49/0.5L OR 16.9 OZ)
DRY:590F -- WET:???F --- TILTON TBR-1 ($11.95/0.25L) (new since 2006)
DRY:590F -- WET:518F --- CASTROL SRF ($79.99/1L 0R 33.8 OZ)
DRY:593F -- WET:421F --- MOTUL RBF 600 ($17.99/0.5L OR 16.9 OZ)
DRY:601F -- WET:399F --- BREMBO LCF 600 PLUS ($26.75/0.5L OR 16.9 OZ)
DRY:608F -- WET:390F --- AP RACING PRF660 ($28.99/0.5L OR 16.9 OZ)
DRY:610F -- WET:421F --- NEO SYNTHETICS SUPER DOT 610 ($11.95/12 OZ)
DRY:613F -- WET:424F --- ENDLESS RF-650 ($33.00/0.5L OR 16.9 OZ)
DRY:617F -- WET:399F --- MOTUL RBF 660 ($28.99/0.5L OR 16.9 OZ)
DRY:622F -- WET:???F --- TILTON TSR-1 ($17.95/0.25L) (new since 2006)
DRY:626F -- WET:???F --- FERODO FSF050 Super Race Brake Fluid ($39.99/0.5L OR 16.9 OZ)
DRY:626F -- WET:417F --- WILWOOD EXP 600 ($20.25/0.5L 16.9 OZ)
DRY:635F -- WET:430F --- PROJECT MU G/FOUR 335 ($45.00/1.0L 33.8 OZ)
DRY:683F -- WET:439F --- PROSPEED RS683 ($39.95/0.5L OR 16.9 OZ)
 
Last edited:
Tubbsy

Tubbsy

Packin' a small bird
Staff member
schred said:
Fark, water-based brakes, in a closed system. Such a sh1t idea, whoever came up with that should be forced to use them.
Click to expand...
Can you expand on that?

Genuine question, I have no idea about the technicality of the subject.
 
S

schred

Likes Bikes and Dirt
See data - the thing that brakes live or die by is their fluid and its ability to maintain its integrity & function in a heated environment - specifically the caliper area. Pads and other ventilated parts help shed heat, but it saturates, and eventually heats up the fluid. When fluid approaches its BP it ceases to function and you'll pull the lever to the bar in an open system & go wide-eyed, or in a closed system the expansion will force the pads onto the disc, slowing you down, and in a vicious cycle of heat + expansion = more heat, possibly will bring you to a fairly rapid stop.

Wet numbers are inclusive of water in the fluid and considered more real world. As water boils at a lower temp, it lowers the fluids BP.
 
Knuckles

Knuckles

Lives under a bridge
Tubbsy said:
Can you expand on that?

Genuine question, I have no idea about the technicality of the subject.
Click to expand...
Water is unable to be compressed, ask anyone who has hydrauliced an engine, so it makes a great hydraulic fluid. However it has a very low boiling point. At boiling point it transitions from liquid to gas, in gas form, it has a higher volume, thus causing expansion in the closed system, and either locking the brakes on at the worst possible moment, or rupturing the circuit at its weakest point, causing loss of breaking. NB: brakes will most likely lock on a long descent, and the front will likely lock first, killing or maiming you.

Conversely, water has a very high freezing point, the point where it transitions from liquid to solid. Ice has a higher volume than water, causing the same concerns as above, the only mitigating part is, the brakes are likely to lock or rupture when the bike is stationary. However if the system doesn't fail at the time of freezing, it will be, at the very least, compromised, weakening the circuit, exacerbating the likelihood of failure close to boiling point.

DOT fluid is glycol based, which if you've ever read a label on a bottle of coolant (anti freeze/anti boil) is what stop your engine from overheating or freezing solid.

Mineral oil also has a boiling point similar to glycol fluids, around the 360°c point and a freezing post of about -30°c.

Water actuated brakes are the worst idea since press fit BBs.

#knuckleswasadrunkenchunt
 
Tubbsy

Tubbsy

Packin' a small bird
Staff member
Thanks for that. Makes good sense.

The Brake Force One people don't seem to think it's a problem...

Brake Force One PR via Bikerumour said:
They say water makes the brake more heat resistant because it has a five times higher heat transfer rate, two times the heat capacity and less expansion under heat than mineral oil. It’s also less compressible, which is why many trials riders have used it. It’s also much more environmentally friendly.

Which begs the question, why doesn’t everyone just use water? “Everyone just imported the tech from cars,” they said, which meant a rethink was in order…

They did everything they could to heat it up, descending 1,500 vertical meters with the brakes constantly engaged and couldn’t get the water over 90°C. On the same test, mineral oil started to fade after 800m, but the water brakes felt consistent all the way down. They say there’s no way to get enough heat energy to boil it outside of the lab.

We spoke to another brake manufacturer just to get a second opinion on the concept and they said that as long as it didn’t boil, it should work, and that most common brake fluids end up absorbing water that then settles at the bottom of the system (i.e. at the caliper), which can be problematic if it boils.
Click to expand...

Maybe they haven't tried them in a hot country... or they're full of shit...
 
Tubbsy

Tubbsy

Packin' a small bird
Staff member
Well at least he can take you back in time to before your spine-snapping OTB.
 
teK--

teK--

Eats Squid
It says it is not pure water, but rather water mixed with glycol coolant to deal with <0deg temps. That would also raise the boiling point of water too. Thinking about it, doesn't coolant also deal with corrosion and lubrication of seals too?
 
Knuckles

Knuckles

Lives under a bridge
Tubbsy said:
Thanks for that. Makes good sense.

The Brake Force One people don't seem to think it's a problem...




Maybe they haven't tried them in a hot country... or they're full of shit...
Click to expand...
Quasi facts.

Yes, water has better thermal properties, but at much lower temperatures.

It sheds heat faster, but...

1) In a closed braking system, where the fuck to?

B)It absorbs heat faster.

3) Ideal operating temperature for distilled water is 22°c so has an inert range of roughly +68°/-18° I doubt you'll even be able to bed in you discs before they fail. Introduce potable water with its various impurities and its window of usefulness is reduced, not to mention problems with Calc and scale, cavitation can be another potential problem in the long run.

#knuckleswasadrunkenchunt
 
Tubbsy

Tubbsy

Packin' a small bird
Staff member
So essentially this is a product designed to whittle down the number of one-percenter MTB riders.

If you're willing to pay 600 Euro for these brakes, you're on the list...
 
P

Paulie_AU

Likes Dirt
I would like to see the data. If the water doesn't reach boiling point then it will work. Also in a closed system if it approaches boiling the pressure will increase which also raises the boiling point (this is how industry make high temp steam). It would be really reasonable to assume the fittings are capable of well over 10barg so temp will be in excess of 160 degrees for boiling.

If they cannot crack 90 degrees outside a lab then it works............ Ahh no lets just armchair it and compare to a car/motorbike and declare it shit.
 
moorey

moorey

call me Mia
Paulie_AU said:
Ahh no lets just armchair it and compare to a car/motorbike and declare it shit.
Click to expand...
Feel free to be an early adopter, Warren Buffet.
My shimano never need bleeding, never boil and never fade. It it aint broke, I aint fixing it. It looks like change for change sake. I'm just surprised they aren't marketing them as Eco Brakes that will reduce carbon footprints :der:
 
P

Paulie_AU

Likes Dirt
moorey said:
Feel free to be an early adopter, Warren Buffet.
My shimano never need bleeding, never boil and never fade. It it aint broke, I aint fixing it. It looks like change for change sake. I'm just surprised they aren't marketing them as Eco Brakes that will reduce carbon footprints :der:
Click to expand...
Yeah Shimano served me well for years and I too cannot see a need to change but that is different to whether a brake designed around H2O is going to work or not.

When I am at work challenging engineering perceptions/norms can (does) save millions. I don't like instantly dismissing a solution that someone has done the work on and says works, but unfortunately as a consumer a good technical trial is a bit difficult.
 
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