understanding brakes
04-16-2009, 06:39 AM
#1
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understanding brakes
http://www.stoptech.com/tech_info/wp...rakedisk.shtml
this has enlightened me on many aspects of the subject. what do you think?
this has enlightened me on many aspects of the subject. what do you think?
04-16-2009, 08:11 AM
#2
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The guy clearly knows more than I do on the subject... not difficult!
That deposit idea is interesting. I always try to break my pads in gradually. Never heard anyone explain the why of the brake noise issue before.
One thing I will say; most shops want to "turn your rotors" when they do a brake job. I think they do it primarily to avoid 'come backs" due to brake squeal.
I have thought this to be the wrong thing to do for quite some time. My thought is that re-surfacing the rotor reduces the thickness of the rotor, thus making it more subject to warpage.
That deposit idea is interesting. I always try to break my pads in gradually. Never heard anyone explain the why of the brake noise issue before.
One thing I will say; most shops want to "turn your rotors" when they do a brake job. I think they do it primarily to avoid 'come backs" due to brake squeal.
I have thought this to be the wrong thing to do for quite some time. My thought is that re-surfacing the rotor reduces the thickness of the rotor, thus making it more subject to warpage.
04-19-2009, 05:36 AM
#3
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The guy clearly knows more than I do on the subject... not difficult!
That deposit idea is interesting. I always try to break my pads in gradually. Never heard anyone explain the why of the brake noise issue before.
One thing I will say; most shops want to "turn your rotors" when they do a brake job. I think they do it primarily to avoid 'come backs" due to brake squeal.
I have thought this to be the wrong thing to do for quite some time. My thought is that re-surfacing the rotor reduces the thickness of the rotor, thus making it more subject to warpage.
That deposit idea is interesting. I always try to break my pads in gradually. Never heard anyone explain the why of the brake noise issue before.
One thing I will say; most shops want to "turn your rotors" when they do a brake job. I think they do it primarily to avoid 'come backs" due to brake squeal.
I have thought this to be the wrong thing to do for quite some time. My thought is that re-surfacing the rotor reduces the thickness of the rotor, thus making it more subject to warpage.
my brakes started shuddering after installing SS lines and galpher pads. After reading this article, I removed the rotors(let them hang) and held a long bolt through the top hole as a guage to find any high spots. Found high spots on both rotors and marked them. Sand blasted(play sand) the marked areas and then lightly blasted the entire surface to equalize. Installed rotors(no high spots), and re-bedded brakes accord to his instructions. Wow. These things will haul your *** down. Stoppy brakes for sure. It's a whole new ballgame.
I'm going to do the rear brakes. Don't use them but for leaving stop to turn.
Last edited by nath981; 04-20-2009 at 04:18 PM.
06-02-2009, 08:24 PM
#4
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update on brakes shuddering at hard application. started to shudder again. took the pads out on one side, sanded(80 grit on flat surface), approx 50 rotations each direction trying to maintain even pressure. sanded evenly until no shiny residue visible, sprayed liberally with brake cleaner. reinstalled and did the other side the same way. result: no more brake shudder, nice and smooth. Hopefully the second sanding will do the trick for good this time.
the stoptech article taught me many things about the nature of brakes/pads and I learned the value of proper brake-in. It also taught me to avoid holding the front brake on at a stop, especially after hard braking, so i have changed the way I approach a stop. I use the front brakes as usual til right before stop at which point I change to rear brakes and release front brake. This works out well since I use the rear brake when pulling out and turning to keep from drifting to the other lane and/or stalling.
http://www.stoptech.com/tech_info/wp...rakedisk.shtml
the stoptech article taught me many things about the nature of brakes/pads and I learned the value of proper brake-in. It also taught me to avoid holding the front brake on at a stop, especially after hard braking, so i have changed the way I approach a stop. I use the front brakes as usual til right before stop at which point I change to rear brakes and release front brake. This works out well since I use the rear brake when pulling out and turning to keep from drifting to the other lane and/or stalling.
http://www.stoptech.com/tech_info/wp...rakedisk.shtml
06-02-2009, 09:09 PM
#5
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One thing I will say; most shops want to "turn your rotors" when they do a brake job. I think they do it primarily to avoid 'come backs" due to brake squeal.
I have thought this to be the wrong thing to do for quite some time. My thought is that re-surfacing the rotor reduces the thickness of the rotor, thus making it more subject to warpage.
I taught a 350 hour Brake and Suspension class for over 30 years, and when the rotors on one of my Toyota 4x4s get warped, I just buy new ones. I blow off the calipers and rotors on my bikes once a week. There's no asbestos in the lining, so it's not hazardous.
And by the way, I've turned or supervised the turning of thousands of rotors, and you are right on about reduced thickness making them more prone to warpage.
You can't machine a Porsche Ceramic Rotor even if you wanted to, and they cost over $5000 each!
Last edited by VTRsurfer; 06-02-2009 at 09:15 PM.
06-03-2009, 04:30 AM
#6
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Since about 10 years ago, GM recommends not machining rotors on their vehicles if they are just glazed or have score marks or grooves less than .060".
I taught a 350 hour Brake and Suspension class for over 30 years, and when the rotors on one of my Toyota 4x4s get warped, I just buy new ones. I blow off the calipers and rotors on my bikes once a week. There's no asbestos in the lining, so it's not hazardous.
And by the way, I've turned or supervised the turning of thousands of rotors, and you are right on about reduced thickness making them more prone to warpage.
You can't machine a Porsche Ceramic Rotor even if you wanted to, and they cost over $5000 each!
I taught a 350 hour Brake and Suspension class for over 30 years, and when the rotors on one of my Toyota 4x4s get warped, I just buy new ones. I blow off the calipers and rotors on my bikes once a week. There's no asbestos in the lining, so it's not hazardous.
And by the way, I've turned or supervised the turning of thousands of rotors, and you are right on about reduced thickness making them more prone to warpage.
You can't machine a Porsche Ceramic Rotor even if you wanted to, and they cost over $5000 each!
Holy Sheeeites! I thought $350-500ea was bad for bike rotors. Hell, If I had a porshe and the rotors needed replacing, I'd have to sell the dam thing or re-fi the friggin house. That's another reason i like my 2-wheeled missle.
With the SH, never had one shudder or any sign of brake malfunction for 18000 mi. Then i put SS lines and new Galpher pads and the problems began. Lightly sandblasted the rotors and sanded the pads and ok for a bit. Put a set of shanghai rotors on to no avail. Then had to sand the pads to a point where there was no more glaze on them and that has ended the problem for now.
Supposedly, bike rotors are less prone to warping than autos but my guess would be that, as the article states, holding the brake on when their hot probably wouldn't be advisable. In a car, you'd have to use the emergency brake to hold you at a stop light or put it in park whereas with the bike you can hold with the rear brake.
PIA screwing around with the brakes. but if they ain't right, you find out quickly how much you depend on having good stoppers.
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