D2Moto Brake Pads

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D2Moto is selling Sintered HH and Carbon Kevlar brake pads for 1100's and 1300's at what I think are ridiculously low prices. These pads apparently have quite a bundle of favorable reviews.

Can someone please explain to me what Sintered HH pads are (I understand the sintered; that's heating a mixture of powders under pressure until it fuses - does the HH refer to the abrasiveness or the coefficient of friction?). And what are the advantages of Carbon Kevlar? And why no letter designation for the carbon kev?
 
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does the HH refer to the abrasiveness or the coefficient of friction?).
yes, HH is the friction rating of the pads, and the OEM pads are HH, so staying with that is recommended. Years ago EBC offered (maybe still do?) replacement pads that were GG rated, and people who tried them were generally unhappy with the lower stopping power they offered. Typical friction ratings on brake pads are FF, GG, HH, there aren't a lot of them. The letters refer to the coefficient of friction at 250 F and 600 F, but they're usually both the same letter anyway.
 

dduelin

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1st H is the level of friction coefficient that a 1" square of that particular friction pad develops under a carefully regimented test of four stops that heat the sample to at least 200 degrees F and not more than 400 F. The second H comes from the average of 10 stops that heat the sample to at least 650 F. In these grade levels HH is the highest level of friction. GG is less, FF is lesser, BB least. The grade letters aren't determined by pad material just what comes out of friction testing.

I think full racing application full carbon pads develop the most but aren't street able. In our world, sintered metal pads are generally HH and organic materials come in as FF, GG, EE.
 
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Someone here will correct me if I'm wrong I'm sure, but its my understanding that organic pads are preferred over sintered pads because their use does not result in as much wear to the rotors. They wear out faster, but pad replacement is much cheaper than having to replace chewed-up rotors. Can anybody out there verify this? I'm thinking that carbon Kevlar pads might be a good choice if they are suitable for street use, but as Dave pointed out that may not be the case.
 

dduelin

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I don't think we can wear out the OEM rotors, fronts anyway, with the ST1300's OEM HH Honda pads. I still had about half of the allowable wear the last time I checked them at 154,000 miles. Besides the pad material, I think the metallurgy of the rotors has a lot to do with how long they last.

My NC700X has EE pads in the rear caliper interestingly enough.
 
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I don't think we can wear out the OEM rotors, fronts anyway, with the ST1300's OEM HH Honda pads. I still had about half of the allowable wear the last time I checked them at 154,000 miles. Besides the pad material, I think the metallurgy of the rotors has a lot to do with how long they last.
Rotor life is going to be like tire life, if you ride highways all the time and rarely brake, you'll get far more miles before replacement than if you ride a lot of stop and go. My ST1100 rotors were done at 100k, as were the rotors on my FZR1000 at a similar mileage, so based on my riding mixture, that's what I get. As they say, YMMV. Coefficient of friction determines the wear rate, you can't have friction without wear, its simple physics. I don't see how Honda's HH friction pads would wear rotors any differently than anybody else's HH friction pads, perhaps someone could explain how that could be possible?
 
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Rotor life is going to be like tire life, if you ride highways all the time and rarely brake, you'll get far more miles before replacement than if you ride a lot of stop and go. My ST1100 rotors were done at 100k, as were the rotors on my FZR1000 at a similar mileage, so based on my riding mixture, that's what I get. As they say, YMMV. Coefficient of friction determines the wear rate, you can't have friction without wear, its simple physics. I don't see how Honda's HH friction pads would wear rotors any differently than anybody else's HH friction pads, perhaps someone could explain how that could be possible?
This is just a memory of what I learned in school - but coefficient of friction is due to many properties of the materials involved. Taking an extreme example, make pads out of grinding wheel material (carborundum) of different grits. The coarser grits might not have a higher co of f, but would grind down the rotor's metal more quickly. I'm not sure this example is even valid - using these hypothetical pads might take us out of the co of f definition and drop us into cutting or grinding technology.

Back to the carbon kevlar pads. Why do they not have a letter designation? And yes, I know that pads for track use must be heated up beyond the temps seen on street disks for them to be effective - and they operate consistently at these elevated temps.
 

dduelin

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Rotor life is going to be like tire life, if you ride highways all the time and rarely brake, you'll get far more miles before replacement than if you ride a lot of stop and go. My ST1100 rotors were done at 100k, as were the rotors on my FZR1000 at a similar mileage, so based on my riding mixture, that's what I get. As they say, YMMV. Coefficient of friction determines the wear rate, you can't have friction without wear, its simple physics. I don't see how Honda's HH friction pads would wear rotors any differently than anybody else's HH friction pads, perhaps someone could explain how that could be possible?
I'm definitely in the camp that uses the brakes a lot. My riding is not biased to highway use and I ride my different motorcycles in approximately the same conditions and style so I can compare my bikes only to each other. An older BMW I had required new rotors at 100K and it used FF pads. Theoretically the disks would not have lasted to 100,000 if the bike used HH pads. OTOH, my ST using HH pads will give at least double that mileage on it's OEM disks. I attribute this difference to the material and construction of the disks.....that was what my last post was supposed to mean. The ST1300s OEM front disks last a long time. I did not mean to imply it's due to the Honda pads alone.

HH rated just means it met HH minimum standard in tests. There are no doubt HH pads with higher levels of friction coefficient and heat resistance than the ones that just made if over the HH standard. I have no idea where Honda's OEM come in at compared to aftermarket but speaking to the OP at least I know that OEM vendors are meeting a Honda standard and quality will be consistent over time. I'm not sure of that with online ebay type vendors so I stick with OEM.

SMSW makes an important point in that abrasiveness is not the same as coefficient of friction. I believe it is possible to have pads that wear the disks faster and have less friction.
 

acedantinne

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Dave, I have a new rotor on my 04 ST1300 from running after market brake pads. I had to replace rear pads on the roads. They chewed the rotor up. They were EBC.
 
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SMSW makes an important point in that abrasiveness is not the same as coefficient of friction. I believe it is possible to have pads that wear the disks faster and have less friction.
I would agree with this statement, some pad compounds might remove slightly more rotor material than others. Given all the variables, and the length of time it takes to wear out the rotors it would be difficult to quantify the actual difference between pad compounds. I suspect the differences would be small, but have no data to support that claim, other than the fact that the pads wear much faster than the rotor, so the rotor is more of an abrasive than the pad.
 
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I would agree with this statement, some pad compounds might remove slightly more rotor material than others. Given all the variables, and the length of time it takes to wear out the rotors it would be difficult to quantify the actual difference between pad compounds. I suspect the differences would be small, but have no data to support that claim, other than the fact that the pads wear much faster than the rotor, so the rotor is more of an abrasive than the pad.
The pads are, by design, softer and meant to wear out faster than the rotor. There is probably no technological reason why we could not reverse the two roles - and force bike owners to remove the wheel, replace a softer, worn out disk, and leave the metal brake pads in place in the calipers. But who wants to go the route of XKE's? Iirc, didn't one have to remove the Jag's rear axle to do a brake job? I heard that this brake job took 8 hours (or the book said to bill the customer 8 hours for the job).

I remember a cartoon from half a century ago - it showed cars with concrete wheels bouncing along on rubber highways.... Would the car owners have potholed wheels?
 
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