I replaced my front brake pads yesterday. First time doing it. Very simple job it turns out. Anyway, I have a few follow up questions:
- the old pads had groves through the friction material. My replacement pads (EBC Double H) have no grooves and are one contiguous surface. What's the difference? My guess is that the grooves allow better cooling and perhaps allow brake dust to vent away better. Meanwhile, grooveless would have relatively more grip, since they have slightly more surface area. Are these assumptions correct?
- what is everyone's favorite way to set the new pads? I haven't gone out to set them yet because it has been raining all weekend. I've read three methods: (1) do a couple of heavy stops at 20mph, then 30mph, etc. all the way up to 60mph; (2) ride 250 miles of urban riding with an emphasis on strong braking; (3) 25 heavy stops at 25 mph.
- I elected to replace the front pads because I've owned the bike for 3 years and have not replaced them, while I'm not sure if/when the PO did. Upon removal, the old pads had plenty of material left, about 3-4mm (I've read that you should replace at 2mm). I decided to replace regardless. Here's the thing, the right caliper had both pads at ~3.5mm thickness remaining; the left had one pad ~3mm and one ~4mm. Why would two pads on the same caliper wear at different rates? Is there something I should check regarding the operation of my left caliper?
- I took the opportunity to clean my calipers using soapy water. They are now much cleaner, but still have some stubborn gray brake dusty splotches. Any suggestions on how to remove these?
I bed in pads like this.
Clean rotors with brakleen and a scotchbrite to remove the old pad material.
On a straight stretch of road with relatively light traffic accelerate to 60 and brake hard 7 or 8 times down to about 20mph.
Then ride home without using the front brake...it needs to completely cool.
Done.
Could it have been a wear indicator groove that you saw?
Quote from: koko64 on June 21, 2015, 10:28:47 AM
Could it have been a wear indicator groove that you saw?
there are none . . . that's "normal". . . at least here where there is a lot of grime even cars are marked like that
Most aftermarket pads do not have the groove. It's purpose, besides making it real easy to see when your pads are worn is to help prevent gas fade* during high speed braking, Totally not needed since your bike has cross drilled rotors.
If you can follow Nate's advice on bedding, do. It works, but is difficult in New York Silly. If you can't, avoid very hard or very light braking for the first 100 miles or so and all will probably be good. Since your rotors are used expect a less than perfect lever until they bed in.
As long as the pistons moved in easily I would not be concerned with the .5mm wear difference
*Gas brake fade occurs the brake pad is actually skidding on a film of gas and brake dust created by the over heating.
Quote from: koko64 on June 21, 2015, 10:28:47 AM
Could it have been a wear indicator groove that you saw?
No, because they went as deep as all the way to the metal, so wouldn't make sense as a wear indicator.
Quote from: howie on June 21, 2015, 10:57:36 AM
Most aftermarket pads do not have the groove. It's purpose, besides making it real easy to see when your pads are worn is to help prevent gas fade* during high speed braking, Totally not needed since your bike has cross drilled rotors.
If you can follow Nate's advice on bedding, do. It works, but is difficult in New York Silly. If you can't, avoid very hard or very light braking for the first 100 miles or so and all will probably be good. Since your rotors are used expect a less than perfect lever until they bed in.
As long as the pistons moved in easily I would not be concerned with the .5mm wear difference
*Gas brake fade occurs the brake pad is actually skidding on a film of gas and brake dust created by the over heating.
I was in the burbs visiting my father for Father's Day, so I was able to find some unoccupied roads to do Nate's method. I thought I did it right, but I think maybe I didn't go hard enough. I let them cool for a little over and hour and then road back into the city. Since it was highway, I didn't need the brakes until I hit traffic in da Bronx. Then they started acting funny---grunting with not effect, then suddenly biting
hard. So I laid off them and used engine/rear braking until I got home. I'm letting them cool now and will test them tonight or later this week.
Didn't think I could, but I may have screwed up the bedding process. Nate's instructions were pretty clear, and jibed with stuff I read online, so this is 100% human error on my part.
HH pads do have a strong initial bite, but I've never experienced a 'delay'.
The HH rating is an SAE designator for cold and hot coefficient of friction. Far as I know, they are the highest rating available for street machines, but there could be some now available which I am not aware of.
As stated, there should not be any "delay".
If it were me, since they are new, I would remove them and clean them with denatured alcohol. Then clean the rotor surfaces, inner and outer. There are tools available for this, so do not try to improvise and use something which might be excessively aggressive. Not having the correct tool, you could safely use some ScotchBrite or BearTex, essentially the same material. Then thoroughly clean the rotor surfaces with denatured alcohol before reinstalling the calipers.
I suggest using alcohol because certain solvents are not universally available in all localities. If Methyl Ethyl Ketone or Acetone is available, use that.
Back in the drum brake days, spray brake cleaner was fine. When the changeover to discs happened, some of the older brake cleaners actually caused material deposits (cementite) on the new discs. Far as I can tell, the safest spray brake cleaners to use on disc brakes now are the ones based on tetrachloroethylene. Once again, those products are not universally available.
Once that is done, go through the bedding process again. It really should not be that difficult.
And that is the long winded version of ducpainter's advice. :)
If you use MEK...which I doubt you can buy in NY...use gloves and do it outside or wear a respirator. I'm not very sensitive to most chemicals anymore, but MEK will give you a buzz you won't really enjoy.
I'm in Fl so can find MEK at some suppliers. When I do, I stock up. I use quite a bit of it, and should know better.
I won't even mention my other favorite solvent, trichloroethylene. [evil]
I worked at a shop that had a trich soaking 'vat'. Great cleaner.
I can buy MEK in NH, but I only used it for one purpose, and I won't do that job anymore.
Quote from: ducpainter on June 21, 2015, 06:28:30 PM
....
I can buy MEK in NH, but I only used it for one purpose, and I won't do that job anymore.
(http://www.empireonline.com/images/image_index/original/75764.jpg)
Nowhere...
near that much fun. ;D
Sounds to me like it just might have taken a while for the pads to bed since they need to conform to your previously used rotors. If your old pads with the groove look like these https://www.bing.com/images/search?q=oem+ducati+brake+pad&view=detailv2&&&id=FED5753E53A6FC9204177C467C276A14E03D225C&selectedIndex=0&ccid=vqvViMSe&simid=608032421858184567&thid=JN.TqSqpzcAji26lOXsngb06A&ajaxhist=0 (https://www.bing.com/images/search?q=oem+ducati+brake+pad&view=detailv2&&&id=FED5753E53A6FC9204177C467C276A14E03D225C&selectedIndex=0&ccid=vqvViMSe&simid=608032421858184567&thid=JN.TqSqpzcAji26lOXsngb06A&ajaxhist=0) (sorry, no tiny URL on this computer yet) they were probably OEM, and definitely have less initial bite than your EBC HH pads, a much less wooden feel too. You should never need more than two fingers with those pads. Do keep in mind I am guessing at what you felt. On used rotors first thing I do is measure the rotors to assure they are still in spec. Yes, even stainless wear. Then, particularly if changing brake pads material clean the rotors as described by oldndumb. CRC BRAKLEEN original (tetrachloroethylene) formula is still available in NYC. I also put a slight bevel on the bottom and leading edge of the pad to help bedding.
OEM are FF.
Thanks, all.
I will try to take the bike out tonight or tomorrow and see how its feels now that the brakes are cooled and settled. My big concern is the grunting/honking noise that occurs when I first make contact. That seems to be a sign something isn't right. I did a visual check and nothing seems out of line, installed incorrectly, etc., wherein it might be rubbing up against a part of the rotor or fork, so I can only assume the sound is related to pad contacting rotor.
Just curious: how much more bite would those of you that know say there is between the HH and OEM? Does it feel 1.5x, 2x,...?
The noise is probably related to the friction material and the holes in the rotors/semi floating nature of the system.
When I turned my rotors into full floating by the hammer method I couldn't believe the buzz they made.
It really depends on how hard you squeeze. Coming from the stock pads you're probably squeezing a lot harder than necessary. You need to modify your technique to be more gentle. The 'feel' is completely different, and a hard squeeze will chirp the front wheel with my Dunlop Pads I use.
Another point to consider is that not all pads are created equally. You might find a different brand more to your liking, or maybe you'll always prefer a less aggressive compound.
Well, the good news is that they stop the bike, which is the point. So I'm safe for now.
Next major ride for me is DIMBY, but based on Howie's, DP's, and Monsterlover's riding style, I don't think brakes will be used much if at all. [Dolph]
When we stop for gas they're handy. ;D
Read your latest post and I suddenly remembered a botched pad swap out I did a while ago. Bike did stop, but there was a weird, never heard before noise. Pulled the pads and found I had installed one backwards! :-[ Strange thing is that the rotor was not damaged.
I know you did not do this, but a quick look see would verify.
Quote from: oldndumb on June 22, 2015, 08:00:43 AM
Read your latest post and I suddenly remembered a botched pad swap out I did a while ago. Bike did stop, but there was a weird, never heard before noise. Pulled the pads and found I had installed one backwards! :-[ Strange thing is that the rotor was not damaged.
I know you did not do this, but a quick look see would verify.
Thanks. I'm not above doing stupid mistakes like that, so I appreciate the suggestion. Pretty sure I got it right, but will double check when I get home.
Quote from: oldndumb on June 22, 2015, 08:00:43 AM
Read your latest post and I suddenly remembered a botched pad swap out I did a while ago. Bike did stop, but there was a weird, never heard before noise. Pulled the pads and found I had installed one backwards! :-[ Strange thing is that the rotor was not damaged.
I know you did not do this, but a quick look see would verify.
Ever install an automatic transmission and just when you were done notice the torque converter sitting on the floor? Did I do that?
Might be a good idea to pull the pads, lightly sand so they are pretty much seated, bevel the edges, clean the rotors, reinstall and bed again. Needless to say all pads need to go back to their original location. Or not. If the bike stops well I would ride it the way it is if the noise does not bother you that much.
Nate is correct, do not expect all brake pads to have the same bite and feel even if they are both HH.
Rode about 8-10 miles of city riding on Monday and didn't notice any problems. Still feel a little different than my old pads, but I am getting used to it. I guess these just took a little longer to bed properly.
Next stop is DIMBY, so that should take care of any leftover bedding needs.
The recommended way to bed your brakes in is as follows.
EBC
Fitting New Disc Pads To Used Brake Discs/Rotors
First of all, there are two different types of brake pad on the world markets which are sintered copper alloy or organic types. The sintered types are of course much harder and take 3-5 times longer to bed in GEOMETRICALLY to any hollow areas or ridges on a worn brake rotor. Organic pads being slightly softer bed in more quickly but also suffer from what is known as “green fadeâ€. Green fade is explained as a heat curing of the brake material which happens over the first heavy heat cycles.
To bed in sintered pads, drive the vehicle carefully allowing extra braking distance for the first 300 miles. Please be aware that brake performance during the bed in period may be significantly less than you have been accustomed to. What you are looking for is to see a 90%+ surface area contact between the pad and the disc or rotor before optimum braking will be achieved.
Once your pads are 90% surface area bedded after the 300-400 miles, on a safe road, use the brakes 10 times in succession stopping your motorcycle from 60mph to 20mph to get the brakes deliberately hot. This is particularly important with the organic versions (Kevlar® types, carbon based pad types and semi-metallic pad types). After this process, the pads should settle down and normal riding and brake performance can be safely achieved.
Taken from the EBC website.
I have not seen any manufacturer other than Mountain Bike Brake suppliers recommend hammering on the pads from new. I was always led to believe this caused the pad to glaze resulting in poor brake performance.
Brembo recommend
• Drive vehicle to a remote area and perform at least 30 brake applications of 3 second duration. Use light/medium deceleration with varying starting speeds. Leave at least 1â,,2 mile between each brake application
• The purpose of this procedure is to gradually increase the temperature in the components without thermal shock, and to mate the brake pad and disc friction surfaces
• After the repeated stops, drive the vehicle for several miles with little or no braking in order to adequately cool the components
• The system is now ready for normal use
Apec
If abnormal braking or force bedding takes place on initial fitment, the disc can distort or the surface of the pad material can become burnt leaving a carbon layer which will reduce braking performance and the pad will take longer to bed and achieve maximum performance.
http://www.stoptech.com/technical-support/technical-white-papers/bed-in-theory-definitions-and-procedures/brake-pad-bed-in (http://www.stoptech.com/technical-support/technical-white-papers/bed-in-theory-definitions-and-procedures/brake-pad-bed-in)
http://www.stoptech.com/technical-support/technical-white-papers/bed-in-theory-definitions-and-procedures/big-brake-kit-bed-in (http://www.stoptech.com/technical-support/technical-white-papers/bed-in-theory-definitions-and-procedures/big-brake-kit-bed-in)
Interesting Ddan, those white papers are contrary to what The big International Brake Pad manufacturers recommend. I suppose you pays your money..... Brembo or Stoptech???? ???
I would probably go with the manufacturer of the pad every time, they know what is in it and how its constructed. If I had Stoptech I would follow their break-in.
Quote from: Yogi on July 15, 2015, 07:00:22 AM
Interesting Ddan, those white papers are contrary to what The big International Brake Pad manufacturers recommend. I suppose you pays your money..... Brembo or Stoptech???? ???
I would probably go with the manufacturer of the pad every time, they know what is in it and how its constructed. If I had Stoptech I would follow their break-in.
The stoptech method works for DP pads just fine. I find it interesting that they don't have a bedding procedure on their site.
Ok, just to follow up on this (and embarrass myself in the process), here is what I discovered was wrong:
To recap: I installed the pads no problem. Did 10 or so hard stops the next day to bed them. Then rode the bike 80 miles home (I keep my mechanics tools at my father's house in the 'burbs). By the end of the ride the brakes would start nicely, then grab really hard, accompanied by a honking/grinding sound.
Here is the "Doh!" part:
At DIMBY, DP and I were looking at something on my bike and I noticed my front wheel, my beautiful gold OZ Piega wheel that cost my $2k a set or whatever, had a major scratch around the rim. Then it all came together...
[bang] [bang] [bang] [bang] [bang]
It turned out that when I installed the pads, I finger-tightened the caliper bolts and then went inside to google what Nm to torque them. But I got distracted and watched something on youtube, had a bowl of cereal, put in a load of laundry, and generally forgot what I was doing. By the time I rode home the next day, one bolt had backed out completely and presumably is still on I678 South somewhere, glistening in the sun. When I braked, the rotor would pull the caliper up, pivot off of the still-in-tact other bolt, and literally grind into the wheel. That was the honking noise and the heavy bite. I'm lucky only 1 bolt backed out. Lesson learned: any noise that is not normal needs to be checked immediately.
One more for the road: [bang]