SRAM launch new powerful Maven brakes

[Steady Spin]

Not to be that guy but.... 

I'll stick to my Hope Tech 3 V4s.

- 10 years old and not a single issue.
- Bled them once in 10 years because I figured it was time. 
- Stops with excellent modulation and power.
- Never felt like they faded on me. 
- Looks amazing with the machined surfaces
 

[dave303e]

30 minutes ago, Headshot said:

I think you're overthinking it on the MTB side. I use some french hydraulic mineral oil in my Shimano's with no noticeable side effects - just good braking and no fade.  I do abuse my back brake a bit. You can click on takealot and order some of the automotive quality mineral oil at under R200 p/l and it will be with you in 3 days. 

 

Sorry its now R202.00 https://www.takealot.com/total-lhm-plus-hydraulic-mineral-liquid-1l/PLID72926639?gad_source=1&gclid=Cj0KCQiAoeGuBhCBARIsAGfKY7zwsNx_Klka_opoQabXyCtkgqNzBF1zwPXdxCZc4jHLmt5o9ap9mswaAonhEALw_wcB&gclsrc=aw.ds

You ever lost half your breaking capacity 180km into a 400km national offroad motorcycle race on a 2t with relatively no engine braking available... I have, that is why I am particular about what goes into my brakes.

We squeezed 4 of our bikes into a van with all kit and camping gear to go to the race and when we arrived I realised my brakes were super spongey. Could only get DOT3 brake fluid at the local town nearest the race and because we were so tight on space no one brought any. That fluid boiled after a few hours and it was a super fun day out for the rest of the day.

So I have my reasons, it is not a fun lesson to learn the hard way.

[DieselnDust]

2 hours ago, NotSoBigBen said:

Genuine question @DieselnDust and other techies, other than maybe downhillers, extreme riders and proper XC riders, should any of us average Joe riders concern ourselves with boiling 

 

 

if you weigh more than 90kg and like the downs more than the ups and are very competent so brakes late and hard then I would factor it in. 
 

if you ride the brakes a lot then maybe it should of concern but the main factor is speed and the energy required to stop

[Headshot]

14 minutes ago, dave303e said:

You ever lost half your breaking capacity 180km into a 400km national offroad motorcycle race on a 2t with relatively no engine braking available... I have, that is why I am particular about what goes into my brakes.

We squeezed 4 of our bikes into a van with all kit and camping gear to go to the race and when we arrived I realised my brakes were super spongey. Could only get DOT3 brake fluid at the local town nearest the race and because we were so tight on space no one brought any. That fluid boiled after a few hours and it was a super fun day out for the rest of the day.

So I have my reasons, it is not a fun lesson to learn the hard way.

No I haven't. I have ridden a fastish 2s bike on the road though and I shudder to think what brake failure would be like.  Which is why I referred to "MTB" brakes of which I have extensive experience over the last 30 years.  They are not the same. 

[DieselnDust]

5 hours ago, Headshot said:

No I haven't. I have ridden a fastish 2s bike on the road though and I shudder to think what brake failure would be like.  Which is why I referred to "MTB" brakes of which I have extensive experience over the last 30 years.  They are not the same. 

No but I will tell you this 

in 2008 cape epic day 3 stage 2 coming down the gamkaberg toward calitzdorp spa my team is had a bit of brake failure. He’s XT’s brake fluid boiled. He then only had the fronts. Had to get a walk parts of that descent. 
we don’t often experience that but the Hope brake systems didn’t have any issues. Magura and Shimano struggled. Both were mineral oil while Hope was DoT.

[MORNE]

17 hours ago, BaGearA said:

Boling water can hurt so stay away from that one.

 

Mineral oil , bad for the system and oil. Flush asap but you still have some decent working service out of the brakes. 

 

Dot , very bad. Because it absorbs water and if it has already then the steam will rise to the top ( your lever ) because it has a boiling point so much lower than the dot and suddenly there will be jack out of your lever , as in nothing. 

 

The above scenarios are super hard to create , even if your brake oil is more than 10 years old. SO don't stress about it too much , regular maintenance on a modern system will give heaps of reliability and decent performance be it dot or mineral based.  

Plus ceramic pistons are now common, which also help isolate heat to the rotor/pad interface. I was breaking in a new set of pads a while back and after a few loops of riding, braking hard, letting off, rinse repeat i squirted some of my water on the pads and it sizzled and steamed like I was frying eggs lol. I thought this was the perfect opportunity to feel how hot the calliper gets and it was barely noticable.

anyway, this is now a few years old already, but i keep referring back to this as it was a substantial lab test. There were not a lot of DOT filled systems at the top of the pile when it came to pure braking power. 

https://enduro-mtb.com/en/best-mtb-disc-brake-can-buy/

 

Also, objectively the most powerful bicycle brakes you can buy (Trickstuff) uses Bionol now (sunflower oil lol) as fluid. Need to try some, apparently it can be used in any mineral oil system: if the color of the bottle hints at the color of the oil, then we know what sram now uses in their ‘mineral oil’ brakes.

“Hydraulic disc brakes typically use either mineral oil or DOT fluid, but the Maxima brakes are filled with something a little different – sunflower oil, or Bionol to be more specific. Created by Danico, the initial boiling point of Bionol is said to be 300-degrees Celcius, which is higher than mineral oil and DOT 5.1. It's not only for Trickstuff brakes, though; Bionol will also work in any mineral-oil operated brake”

 

[DieselnDust]

On 2/23/2024 at 12:32 PM, BaGearA said:

Boling water can hurt so stay away from that one.

 

Mineral oil , bad for the system and oil. Flush asap but you still have some decent working service out of the brakes. 

 

Dot , very bad. Because it absorbs water and if it has already then the steam will rise to the top ( your lever ) because it has a boiling point so much lower than the dot and suddenly there will be jack out of your lever , as in nothing. 

 

The above scenarios are super hard to create , even if your brake oil is more than 10 years old. SO don't stress about it too much , regular maintenance on a modern system will give heaps of reliability and decent performance be it dot or mineral based.  

Not sure what ls going on here in bold. Very confusing. I think you mean mineral. DoT absorbs water but its reflux boiling point is still much higher than mineral or water. Think of engine coolant, ethylene glycol, it raises the waters boiling point to prevent overheating and pump cavitation. DoT has a similar property. Mineral has to do the same but it’s not as good at it 

[michaelbiker]

Forgive me if this is a stupid question but why don’t we need to replace the oil in our car brakes every year like it’s recommended on DOT oil bicycle brakes? Is this a requirement on motorcycles too?

[hansolo]

Loving how we are going round in circles "inventing" new stuff to end up basically where we started...

Pretty soon SRAM will be touting new "less powerfull" brakes to make you go faster or a new standard to mount these stronger brakes to your bike. 

Hoping I don't sound like a Luddite but I really think we could do with better lower end components for the masses rather than just making more and more expensive components.  

[dave303e]

2 hours ago, michaelbiker said:

Forgive me if this is a stupid question but why don’t we need to replace the oil in our car brakes every year like it’s recommended on DOT oil bicycle brakes? Is this a requirement on motorcycles too?

 

Wall mounts, sketchy travelling, working on the bike upside down, often the brakes get bumped and the air in reservoir goes into the system. Cars also are not weight weenie-ing to the max so the seals and build is often a lot stronger, with power assist brakes as well the seals can stick a lot more, but with a bicycle your hand must actuate that piston so they can't get too much of a tight fit/seal. 
Ford ranger service schedule says new brake fluid every 2 years.

[Shebeen]

On 2/23/2024 at 2:36 PM, dave303e said:

You ever lost half your breaking capacity 180km into a 400km national offroad motorcycle race on a 2t with relatively no engine braking available... I have, that is why I am particular about what goes into my brakes.

We squeezed 4 of our bikes into a van with all kit and camping gear to go to the race and when we arrived I realised my brakes were super spongey. Could only get DOT3 brake fluid at the local town nearest the race and because we were so tight on space no one brought any. That fluid boiled after a few hours and it was a super fun day out for the rest of the day.

So I have my reasons, it is not a fun lesson to learn the hard way.

surely the braking forces on a motorbike are way increased over a mtb? We don't compare chain issues between motorbikes and mtb, so why braking? nothing wrong being overly cautious but i reckon mtb specific sceanrios would be a lot more relevant.

 

[question for the experts - @DieselnDust] Also, to boil something takes a lot of energy so it's one thing getting to boiling point but another issue going past it. Even then my physics brain tells me the brake hose should then become pressurised and the calipers should bite - why do they become squishy?

 

 

[DieselnDust]

10 minutes ago, Shebeen said:

surely the braking forces on a motorbike are way increased over a mtb? We don't compare chain issues between motorbikes and mtb, so why braking? nothing wrong being overly cautious but i reckon mtb specific sceanrios would be a lot more relevant.

 

[question for the experts - @DieselnDust] Also, to boil something takes a lot of energy so it's one thing getting to boiling point but another issue going past it. Even then my physics brain tells me the brake hose should then become pressurised and the calipers should bite - why do they become squishy?

 

 

Great question!!

In mineral oil, water has to be entrained in the oil. These oils have an affinity to absorb water but when heated will release that water more easily than a glycol (DoT oils)

Boiling point is not so much the issue but rather bulk modulus. We refer to boiling point because there a correlation to bulk modulus. Liquids are generally considered as incompressible right…,

but that’s at room temperature. Get a liquid close to its boiling point its bulk modulus changes and it can then be compressed. When it boils it’s a gas and gas bubbles are compressible. 

so we accept that hydraulic oils absorb water. In many large hydraulic systems we fill fit filters and coalesces to know the dirt and water out to very low parts per million levels. There’s no such luxury in a vehicles braking system so we need an expansion chamber to allow for fluid expansion at temperature and also an oil that can hold onto water molecules so that they behave as fishery have a higher boiling point. To do this the water molecules have to be separated from each other and bonded to the oil or something in the oil. Glycols do this quite effectively which is why they are used in brake fluids in all machines. Mineral oils have limited capacity to do this because it’s achieved through a small dose of emulsifying additives. Can’t have to much because water emulsions have bulk modulus problems ( will need a big expansion chamber). 
 

so to answer why does the lever feel squishy?

Generally this won’t happen during braking. A hit brake will often suffer face due to either pad material overheating and friction reducing, or due to fluid boiling and gas bubbles compressing because of excess water in the oil. Even at small quantities, water that isn’t bound to the emulsion additive in mineral oils will boil due to pressure and temperature from the braking and pressure. Remember under pressure the water won’t boil at 100C, it will boil at a higher temperature but this is still lower than the surrounding oil or glycol.

[Shebeen]

21 minutes ago, DieselnDust said:

Great question!!

In mineral oil, water has to be entrained in the oil. These oils have an affinity to absorb water but when heated will release that water more easily than a glycol (DoT oils)

Boiling point is not so much the issue but rather bulk modulus. We refer to boiling point because there a correlation to bulk modulus. Liquids are generally considered as incompressible right…,

but that’s at room temperature. Get a liquid close to its boiling point its bulk modulus changes and it can then be compressed. When it boils it’s a gas and gas bubbles are compressible. 

so we accept that hydraulic oils absorb water. In many large hydraulic systems we fill fit filters and coalesces to know the dirt and water out to very low parts per million levels. There’s no such luxury in a vehicles braking system so we need an expansion chamber to allow for fluid expansion at temperature and also an oil that can hold onto water molecules so that they behave as fishery have a higher boiling point. To do this the water molecules have to be separated from each other and bonded to the oil or something in the oil. Glycols do this quite effectively which is why they are used in brake fluids in all machines. Mineral oils have limited capacity to do this because it’s achieved through a small dose of emulsifying additives. Can’t have to much because water emulsions have bulk modulus problems ( will need a big expansion chamber). 
 

so to answer why does the lever feel squishy?

Generally this won’t happen during braking. A hit brake will often suffer face due to either pad material overheating and friction reducing, or due to fluid boiling and gas bubbles compressing because of excess water in the oil. Even at small quantities, water that isn’t bound to the emulsion additive in mineral oils will boil due to pressure and temperature from the braking and pressure. Remember under pressure the water won’t boil at 100C, it will boil at a higher temperature but this is still lower than the surrounding oil or glycol.

[The Ouzo]

3 hours ago, hansolo said:

Loving how we are going round in circles "inventing" new stuff to end up basically where we started...

Pretty soon SRAM will be touting new "less powerfull" brakes to make you go faster or a new standard to mount these stronger brakes to your bike. 

Hoping I don't sound like a Luddite but I really think we could do with better lower end components for the masses rather than just making more and more expensive components.  

developing high end tech generally eventually means the technology trickles down to the lower end.

Think about cars, tech we have as standard in lower end cars now was high tech stuff reserved for top end models only in the past. 

Think groupsets, Shimano 105 today has tech from Dura-Ace and ultegra of a few years back.

Thats generally how the normal R&D works.

[Headshot]

I am not a fan of the look of the latest flat facing SRAM levers and these don't disappoint. They do seem to be very effective brakes though...

[DieselnDust]

SRAM brakes developed due to leaps and bounds of the erratically funcytioning taper bore brakes of the mid to  late 2000’s. 
Once they stopped trying to reinvent the wheel (stopper) their brakes actually worked very very well. I still have Guides with revised lever internals that are strong and reliable