A conversation recently got me thinking about this. Generally, stainless steel braided brake lines are recommended 'because race car', and I get it, theoretically giving the driver more direct control of the brake pads' pressure on the disk seems like a potential performance bonus.
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But what is the actual performance delta (in the metric that matters, the time saved to get around the track)? It doesn't seem like the advantage would be available to all drivers either, so what level of driver do you have to be to benefit? I also admit that there may be different advantages to braided lines that aren't based on lap time. Maybe they do better when everything gets smoking hot, for example. Or maybe they are easier to visually inspect for damage between races? But in this thread I'm focused on lap times.
Has anyone actually tested braided vs rubber for time?
For me it's purely modulation; that extra bit of feedback makes it easier to be consistently aggressive with the brakes. I may have some bias as on motorcycles there was a night and day difference. On my Datsun the pedal feel also improved a lot.
I also think there is a secondary consideration on race cars as the braided lines are more resistant to damage
With modern ABS braking systems the advantage is probably less than I has a driver imagines it is.
Yeah any difference in lap time is probably too small to measure, it just makes a slight difference in pedal feel, not worth the packaging issues that come with these lines IMO. I've done them once and I think I'll stick to rubber in the future.
They can actually be harder to inspect for damage since they tend to fail from the inside-out, while rubber lines tend to fail from the outside-in.
I don't believe there is any performance advantage. "Feel" improvements are just that "feel".
The reason I say this? Modern performance ABS systems provide perfect multi channel threshold braking using RUBBER lines. If there was any performance loss in the ability to detect the bite point and provide the optimum tire slip angle due to "squishy" fluctuations in line pressure caused by rubber lines they would run different kinds of brake lines. I assume race cars run braided lines mostly for durability reasons vs pure performance.
It would be an interesting test though to take something with really good Stability control and braking like a 911 or C8 Vette and then swap ONLY braided lines and see if there really is any improvement. Do it both with all driver aids on and off.
The main advantage to braided lines is you can do your brake system in -3 AN and get rid of all of the weird banjos and double flares and bubble flares, so you need to carry fewer spares and can even make your own lines at the track.
The main downside is that braided lines seem to be a lot more fragile. When pinched or hit the braid gets damaged and the line blows out. So you get to gain more experience making your own lines at the track.
Direct fit braided lines seem like the worst of both worlds to me.
nocones said:The reason I say this? Modern performance ABS systems provide perfect multi channel threshold braking using RUBBER lines. If there was any performance loss in the ability to detect the bite point and provide the optimum tire slip angle due to "squishy" fluctuations in line pressure caused by rubber lines they would run different kinds of brake lines. I assume race cars run braided lines mostly for durability reasons vs pure performance.
I do wonder about the validity of comparing what a computer controlled system can achieve vs what a human can do. Everything about the ABS system is optimized around the rubber lines so things like the volume and frequency of each pulse will take the system compliance into account. The human on the other hand (or foot in this case) can't move at the same speed or with the same ability to go directly to a pressure...I'm pretty sure switching to braided lines on an ABS car does nothing helpful, but I'm also pretty sure human controlled braking will be better with braided lines.
In reply to mke :
I'm not sure. Compliance in the brake hose should be fairly linear based on the spring constant of the rubber material. If the primary feedback for threshold braking is brake pad forces on the caliper piston then I could see an impact on human controlled braking as there would be a very slight dampening of this pressure feedback. But I don't believe that's the case. I believe you are generally trying to feel tire forces through seat of pants and some steering weighting and that is the feedback loop that makes you apply pressure through your foot. I think in this feedback loop the rubber hoses are a relatively constant in the system similar to caliper flex, and general flex of the brake components.
But it is absolutely worth a test to see. And the comparison of computer control to human would be really interesting.
Well, 2 things strike me.
1. It should be easy to measure the "compliance" of a rubber line per foot or line diameter or whatever. How much more compliant is a brake line than a stainless line (probably not all braided lines are created equal either)? How much more volume goes into a rubber line at a normal threshold pressure? If the real difference in compliance is small enough, there's our answer.
2. Theoretically I could see that a little compliance is actually a good thing. The ground is never flat, so the forces going into the tire are never constant, so the forces going into the wheel are never constant and so forth. That means that if you graphed the maximum threshold pressure in the caliper over time you would not see a flat line. If the rubber line has a bit of compliance in it, then you would better "average" those peaks and valleys than a line with no compliance.
But I also know that theory is not always a good predictor of practice. Which is why I'm curious if anyone has ever tested the lines back to back for time advantages.
I think whether or not the car has ABS is an important question. With ABS you pretty much just mash the pedal to the floor until it starts pulsing then back off a hair. Without ABS it requires a lot more feel to brake close to the threshold without locking up. Either way, a good driver will adapt as long as the car's behavior is consistent. Rubber lines may feel mushier, but as long as they're consistently mushy then I don't think they're any slower than braided lines.
All of my real track experience was on motorcycles in the 90s so everything could be different now. At the time though there was almost no such thing as a bike without braided lines...even in the production classes that was 1 of the only mods allowed because they considered the mushiness of rubber lines a safety issue...the difference in brake feel and response was just night and day. But that was then, I really don't know what is done today...which is sad
Aeroquip style metal braided lines with PTFE inners are certainly good at improving feel over even a new regular rubber line. I am not so sure whether the reduce slowing times on the track.
I do know that if a single one of the steel wires that make up the outer sheath breaks it can cause failure and I had one instance when there were no broken wire bits yet the PTFE liner had somehow rubbed on the inside of the braiding on a line on one of my race cars, which resulted in a pinhole leak that fortunately manifested itself when I was under the car bleeding the brakes - all of a sudden a really fine stream of fluid shot out!
I know that I prefer the feel of braided steel lines over rubber enough that I'll run them if the rules and budget allow but are they actually faster? I don't know. I suspect the answer is, it depends.
Rubber lines not only increase pedal travel they also make the pad clamping pressure to pedal displacement non-linear. On the initial pedal movement the pads move out till the contact the rotors. Once they're in contact the pressure increases in the system linearly as the pedal if moved further until it reaches a point where the lines start to swell. At that point continuing to move the pedal increases system pressure at a lower rate until the lines stop expanding (or the rate of expansion slows) at which point the original pedal movement\pressure increase ratio is resumed.
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It's that non-linearity that's perceived as lack of feel. If threshold breaking requires pressure modulation in and around the range where the change in the pedal movement\pressure ratio occurs then the impact on lap times could be significant. Otherwise it's probably just a driver comfort/confidence thing and that's harder to quantify.
Speed merchants may not like to admit it but the ability to stop in good time far outweighs the importance of lightening quick acceleration. With that in mind, appropriate brake pads go some way towards ensuring motorists’ safety on the road.
So what are they? Put simply, the component that applies the requisite pressure and friction to brake rotors, allowing a car to stop.
A more technical description would explain how they are in fact steel backing plates, with a friction based material bound to their surface. This friction is utilised to convert the kinetic and thermal energies of the vehicle.
Two of them are housed in the brake calliper, their friction surfaces aimed at the rotor. Whenever brakes are applied, the calliper clamps this pair of pads onto the spinning rotor and - as if by magic - a car slows or comes to a complete halt, depending on the pressure involved.
The absence of sufficient brake pads will lead to wheels being worn down, reduced braking power and – ultimately - a damaged braking system.
Nevertheless to many the how and why are not important, so long as their brake pads pass a yearly MOT. But different types suit different models, which should pique even the casual driver’s interest.
Perhaps the most commonly found brake pads, semi-metallic models consist of between 30% and 65% metal. Additional material could include steel wool, wire and copper among others.
Once settled upon these elements are bound together by organic resin. From here they are moulded into pre-set shapes and baked into a furnace, resulting in greater durability.
That robustness is one of their many benefits. Semi-Metallic pads are resistant to heat and far easier on rotors than their Ceramic equivalent. They tend to be cheaper and – when around 60% metal is present – lend themselves to heavy braking over a long stretch of road or track.
Indeed Semi-Metallic brake pads are perhaps best suited to high performance race cars. If you own a vehicle that does 0-60mph in a flash this is the option for you.
As with all types of pads there are downsides, in this instance an adverse reaction to extreme, low temperatures. Avoid taking her for a spin in the Antarctica.
By far and away the dearest option, you are likely to own a supercar if possessing a set of ceramic pads. Why the cost? In truth they make for excellent braking, absorbing heat generated from even the harshest, sharpest stops.
Composed of ceramic fibres and similar type fill materials, these pads are cleaner and quieter than any others featured in this blog. They last longer too, outperforming organic pads in particular.
A major drawback is just how long it takes to warm them up to an operating temperature. So while ceramic pads are ideal for rallying, they are all but pointless when installed in the average car, which would seldom reach the optimum performance heat on the likes of the school run or weekly shop.
Better breaking is realised with the Low-Metallic NAO option, the result of an organic formula mixed with between 10% and 30% copper or steel. This recipe certainly helps with the transfer of heat. They are however on the noisy side, while the added metal can create plenty in the way of dust.
As the name suggests these brake pads are made from largely organic materials. That wasn’t always the case. Indeed there was a time when pads were constructed from asbestos, only for the mineral to be displaced by other compounds amid health and safety concerns.
Softer and relatively quiet, newer versions may include fibre glass, rubber or Kevlar, not to mention resins such as cellulose.
Despite being easier on the brake discs themselves, Non-Asbestos Organic pads will wear fast and are only suitable for day-to-day road driving. What’s more they do not lend themselves to regular braking.
The aforementioned Kevlar option – despite being the most expensive – does at least come with fewer drawbacks.
When it comes to fitting brake pads there is no substitute for research. Ask your local garage, canvass opinion on forums and read up on the pros and cons of each type before making a decision.
That said there is a general acceptance that lighter, compact vehicles are best suited to organic brake pads. They will afford the stopping power required, whilst producing minimal sound. They are also relatively cheap to purchase.
Medium sized cars meanwhile need that little bit extra in the way of stopping power. A low metallic NAO is therefore most appropriate, just be prepared for increased volume.
If you’re lucky enough to own a sports car and crave more in the way of acceleration, plump for semi-metallic or high performance ceramic brake pads. Both will ensure you come to a halt before taking off.
Finally, lorry drivers and those lugging significant loads need more in the way of metal content. Severe duty pads may even be necessary to provide that additional protection.
MAT Foundry’s Group’s parent company, MAT Holdings, has its own division dedicated to brake pads. Friction Group boasts 7,200 employees worldwide, split between twelve factories and three continents. Between them they produce more than 140m brake pads and 10m brake shoes per year – these delivered into the passenger, commercial and heavy duty markets. To find out more visit their website,,
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The average lifespan of a set of brake pads is around the 50,000 mile mark. Newer models come with a warning light that indicates when a change is necessary but loud screeching, bad vibration, obvious wear and tear and a car’s tendency to pull to one side provide further clues.
So keep an eye on your brake pads, they matter more than you might think.
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