Larry Herman

In the current and previous brake threads there is always talk about "good initial bite". What do you consider to be good initial bite, and why do you want it?

You can see where I am going with this. I am not a proponent of this concept. I want my brakes to be linear, with good release properties; not the opposite. Afterall, you don't just jam on your brakes in hard braking zone, you squeeze them on and ramp up the pressure. Then as you bend into the turn, you need to gradually get off of them. So in my book, I want the most linear stopping power that I can get, so it is predictable, and will not cause premature lockup (or ABS trigger) due to them being grabby.

Also, there are plenty of times where I am just applying minimal brake pressure to slow the car a little. The last thing that I want is for the brakes to grab and plant the car on its nose, and destroy all my momentum.

Just like I want my steering to be accurate but not darty, and I want the motor to pull smoothly throughout its range with no power surges, I want my brakes to be completely linear, providing proportional stopping power vs brake pedal effort for whatever speed or decel rate I need.

What do you look for & why?

Circuit Motorsports

I find that the 'good initial bite' comment falls in teh same category as a 'momentum car'.

weneversleep

Larry, I agree with you.

I used to think that I wanted brakes that immediately sucked your face into the windshield the moment you applied any kind of pressure. I didn't like my stock M3 brakes at first, because they didn't have this feeling.

As I became a more experienced track driver, I began to realize the value of "progressive" brake feel and how this allows better modulation. The combination of stock M3 calipers/rotors, along with PFC race pads, provides this feel for me.

If you want to feel "good initial bite", go drive a 2005-2006 Audi A6. My wife has one, and I maintain it has the worst brake feel in any car that I've ever driven. It's either 100% or nothing, from the moment you step on the pedal. It sure has "initial bite", though.

--michael

multi21

It depends.

For track you want progressive especially considering the speed and the ability to modulate pressure especially in longer braking zones. It helps with keeping a rear brake bias as well.

For autocross, because of the lower speeds and the need to brake as late as possible and in the shortest distance possible, you want that initial bite to be strong. More brake bias to the front also helps with turn in on slower corners by getting the back end to rotate better (at least in a 911 with wider rear tires)

va122

For trail braking I don't want this bite, throws off the balance and weight transfer.

For autox I don't nessarily want the bite I want the brakes to heat up ASAP or i won't stop and mow down some cones. My PFC's don't heat up fast and is annoying. (disclaimer, they generate a great deal of heat but it takes some time)

MUSSBERGER

ABS? Is that something new?

himself

I'm not sure how "good initial bite" somehow got pigeonholed into "full force, ABS inducing, flat spot creating, spin inducing, braking when you barely touch the brake pedal" - but I think that definition is wrong. I don't think there is any requirement to mash the brakes to have "good initial bite." Rather, "bite" is an inherent characteristic of the pad itself. I also believe that "good initial bite" and "good release" and "linear" are an apples and oranges and pears comparison.

If you look at the word "bite" itself, it means (to me anyway) a pads friction coefficient. So, "initial bite" means the friction coefficient when brakes are applied. To me, "good initial bite" simply means that the pad itself has a "good" inherent friction coefficient, and that is applied at brake initiation. "Good" is relative to other pads, or is a marketing word that has little context. But, suffice to say that "high/good/agressive/etc" bite is more friction on a track pad than a street pad.

By "linear bite," I think you mean the pad has (close to) the same friction at initiation as it does later in the braking zone. More pedal will get you more "bite" - but in a linear fashion. That is, if you had "progressive bite" that would imply increasing coefficient of friction as more heat is generated, which might still be linear, just not horizontal. Good/better/more/etc "initial bite" when compared across pads implies a higher initial coefficient of friction - which means using less pedal and not dive bombing the car.

As to your point about consistent braking power, IMO "initial bite" is the limiting factor regardless of whether it is good, high, low, agressive, etc. That is, you want braking force to remain constant around the initial "bite" level, and to remain consistent based on the amount of pedal force applied. [Of course my understanding could be wrong if you actually meant "linear braking" as a sloped increasing coefficient of friction so that you can get more stopping power late in the braking zone without adjusting pedal pressure.]

Personally, I categorize endurance pads as having less "initial bite" than sprint pads. Consistency ("linear braking") and release qualities vary between compounds.

-td <- probably full of BS

wanna911

^^^ Last comment above is why I don't like pagid yellows^^^


Whatever Pagid Blacks do, I want that. Not a grabby bite, but strong enough to let you modulate easily. Actually for practice and learning, some brakes with no bite would help you realize where you are overbraking, but when you need to really get on the brakes it's nice to have that BITE!!!

Bob Rouleau

Funny, the perfectly linear response is why I prefer the pagid yellows. Different strokes I guess.

Rassel

Predictable behaviour so I know how they act from cold to warm. No surprises please..

Communicative, so I can can modulate from a quick tap on the pedal to maximum brake without lock-ups. No on/off-situation.

Then there's the usual about stopping power, reliability, braking system configuration and bla bla bla..

Larry Herman

I characterize a pad with high intial bite as one that will produce a strong braking effect with rather light pedal pressure, then additional (but less pronounced) braking as pedal pressure increases. Pads with minimal initial bite will produce a lot less braking with the same pressure as above, but ramp up braking effect with increasing pedal pressure in a more linear fashion to possibly the same resultant level. I have attached a graph to show what I am trying to explain here.

Chads996

This is a very open ended discussion, IMO. Each driver has his/her preferred configuration regarding what they prefer using for brake pads. There is no right or wrong answer.

In my case, I prefer a set that has a slight initial bite then provides a linear progression in the pedal. That initial bite lets me know they are there, and are ready to work. If the brakes are over heated and that bite is minimal it lets me know immediately what the problem is. One of the reasons I really like the Performance Friction 01 Race pads. Great initial bite with a very linear progression.

C.

333pg333

I have to add, I think it depends on what you're used to. So for guys with modern cars / braking systems they might not want to feel a h.i.b. whereas older cars that are prone to having longer pedal travel or occasional soft pedal, then some h.i.b. seems like a nice idea. I remember switching from some fairly ordinary pads over to PFCs 01/97s and I was dumbstruck at the difference. For all the previous time I thought that's how my car braked. It made a huge difference but perhaps that was all just a relative perspective. I now use Pagid Blacks and like them.

333pg333

Also I wonder if there is not a difference between turbo and n/a cars? As in some n/a cars do tend to need more of a linear slowing and increasing of speed and may require a brake setup that reflects this. Turbo cars may tend to be driven in a different manner?

quickxotica

You can always brake more softly/smoothly where that's beneficial just by softening your footwork. But for those braking zones where sufficient traction is available and max decel is required, I want a pad that takes me from peak Accel G's to peak Decel G's in the shortest time possible. If you call that "good initial bite" or whatever, fine, I'll take it.

The main thing I don't want is a pad whose friction changes over the length of a braking zone while pedal pressure is steady (e.g. because of temp).

I am happy with Pagid RS-14 Blacks. Peak Accel to Peak Decel in the 0.75-0.9 sec range when called for (and that includes the roughly 0.5 sec it takes just to get my foot from the floored throttle up onto the brake pedal).

But...to each their own.