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2011 brake issues

4K views 60 replies 10 participants last post by  Twistychaser 
#1 ·
This is my first post. Thanks for having me. I was riding yesterday and let a turn sneak on me and got in my brakes really hard. From that point on, if I get in the front brakes, the front end gets super chattery. What did I possibly damage? Did I warp the rotors, overheat the pads? All oem system. What can I do to correct this, as I'm wanting to start doing some track days next year and want to atleast upgrade to track grade (not race grade as i will be a newbie on a track) Thanks for any help.
 
#3 ·
I saw your other post asking about used rotors and calipers... there is no way you damaged anything using your brakes. Worse case scenario you deposited a heavier layer of pad residue on the rotors and now the “feel” is different. I would put the bike up on stands, and clean the rotors with some fine sand paper and then wipe them down with either brake cleaner or acetone to remove any deposits. If you want to be really thorough, you could also remove the calipers (don’t disconnect the brake lines!) and then remove the brake pads, and finally clean the calipers thoroughly with a mild dish detergent, distilled water, and a tooth brush; you should be doing that at least a couple times per year - more frequently if you start doing track days. I get out a bucket, hold the caliper over it, and use a spray bottle with the soap and water mix and spray it on the caliper. Then start scrubbing with the toothbrush and follow with another spray bottle with straight distilled water. All of this dirty liquid ending up in your bucket. I like to use some compressed air to help dry the calipers and then reassemble.

Finally, the way you retighten your caliper bolts is again, with the bike still on the stands, put the calipers on and only tighten the caliper bolts finger-tight. Spin the front wheel with one hand, and then grab the front brakes with the other hand and repeat a couple times. On the last “spin and grab” do not release the brake lever, then use your wrench to tighten the caliper bolts securely. Release the brake lever and use a torque wrench to set the caliper bolts to 34 N-m. All this was to properly align the brake pads with the rotors.


All of this will allow you to inspect and regain confidence that things are okay.
 
#6 ·
Duc, hopefully you'll see this in the next little bit. Ive got the wheel off cleaning everything up really good. Just had a question. When you were mentioning lining everything, you never mentioned at what point to tighten and torque the axle nut. Where would that come in the order of re-assembly? Thanks for all of your help so far as well!
 
#7 ·
Sorry. I didn’t expect you to be dealing with the axle. All the stuff I mentioned can be done without messing with the front wheel. If the axle needs to be torqued, because the front wheel was removed, that would be done before the brakes. And the axle, per the manual, needs to be tightened down in its own sequence.
 
#9 ·
Yea I went ahead and pulled the wheel. I completely removed the rotors from the wheels and gave them a thorough cleaning. They are torqued back to 20 ft/lb per a torque value sheet I found for most bolts on the bike. I just got everything back together with everything still finger tight. So I will do the axle now, then the calipers. Thanks so much for your guidance. I will let you know in a bit if the chatter is gone.
 
#40 ·
#15 ·
What you are describing sounds like a warped rotor. If the rotor is warped, it will push the brake pistons back into the caliper every time the rotor comes around while you are on the brakes. This will push fluid back up into your master cylinder and back to your caliper causing a pulsating feeling in your brake lever.
The service limit on rotor runout is 0.010" so even though it may have "seemed straight", it could very easily be well out of specification. I would suggest purchasing a dial indicator to check your rotors before you start throwing parts at it. They are fairly cheap online and can be used for all kinds of things. Also if this is not fixed soon, you may find yourself having caliper or master cylinder issues as well.
 
#14 ·
It’s a long shot, but I had trouble like you are describing - but during heavy braking at track days - apparently because when I installed my front axle I wasn’t torquing it to 127 N-m as specified in the manual; I had been been lazy and since my 1/2 inch heavy-duty torque wrench had broken I was using the 3/8” one that maxed out at 105 N-m. I spent years chasing that ghost! Thought it was pads/rotors/steering head bearings/ you name it. The last thing I did before it going away was buy a new torque wrench and give it the full 127.

Best of luck ... at least you now have clean and aligned brake calipers and rotors!
 
#17 ·
Stopped by HF and picked up the stand on my way home. Checked runout in the only clear spot on the rotor, just inside of where pad stops contact. There was a total needle movement of .006 on both rotors. That's an sd of like .003. Seems very negligible. Could this be a symptom of terrible or even just very old pads crystalizing do to over heating? That seems like the cheapest place to start. I'm looking to upgrade brakes before next season anyway for track riding, so I don't guess it will be terrible to throw on a few things I plan to upgrade anyway.
 
#18 ·
Stopped by HF and picked up the stand on my way home. Checked runout in the only clear spot on the rotor, just inside of where pad stops contact. There was a total needle movement of .006 on both rotors. That's an sd of like .003.
That is within spec. Next thing I would check is the pistons in the caliper. One may be stuck causing the piston on the opposite side to push the rotor out of being true to the wheel. Also check the brake pad pins for grooves. And yes, buy new brake pads.
 
#25 · (Edited)
There is no debris. I pulled them off of wheels and thoroughly cleaned them. I'm going to pull wheel off today and take it to a shop and just have a balance verification and see if they can replicate my runout numbers.

The pads look like quality pads that are currently on the bike is what has me worried that may not be the problem either. This seems like the cheapest place to start.

One more thing I just thought of, is it possible that previous owner put on pads that aren't compatible with stock, stainless rotors?
 
#33 ·
You have aluminum carriers with semi-floating rotors correct? Semi-floating movement is not checked by face runout. Chances are you've got a couple of bobbins bugered up from dirt and a good stoppie..... they can be cleaned and freed up,the vibration may smooth out some but will most likely still be present as that'll do a number on the weakest point- an aluminum carrier. (Had this problem..... you noticed fork vibrations? That'll also do a number on steering bearings).
 
#35 ·
Sorry for taking so long guys. I was getting frustrated so I took a couple of days off. I'm going to start messing with it again today.


Can I clean these by removing rotors from wheels and cleaning the bobbins with a pressure washer?

Can you explain what you are feeling under braking a little more in detail?

Does the bars shake side to side, is it more up and down, does it just vibrate?

Honestly, if you are gonna do track days, just go ahead and get some better brake pads, I love my HH sintered (even though not street legal, though I use them on street). That will take the pad guesswork out of the equation. Also, you could go ahead and throw in some DOT4 brake fluid and flush your system. Both of these are good to do before you start going fast at track days anyway and are relatively cheap.

Besides that, the only other thing I can think of is your rim might be bent a bit and you don't notice it until most of your and your bike's weight is on the front wheel. I can't imagine this being a suspension problem, but you could always message Dave Moss from Dave Moss Tuning and throw it by him. He wouldn't charge ya for a Facebook answer I don't think.

Post a picture of your front tire. That would tell us if you have front rebound at some crazy amount or even if your compression is way off. Also, throw a zip tie on your front fork and go do a 60-0 HARD brake and see if you are bottoming out your forks.

- Donnie
When I grab front brake, the chatter feels up and down. Looking at the lower forks, you can also see rapid fork travel in and out. I guess I feel it in the handles but can see the forks reacting aggressively.

I will put zip ties on later and see what that looks like. And look into brake pads and fluid. Would you go with ebc hh or vesrah rjl's? Also what brand of fluids are good to switch over to? I want to start using 1 brand for all of my fluids once I start track days.
 
#34 ·
Can you explain what you are feeling under braking a little more in detail?

Does the bars shake side to side, is it more up and down, does it just vibrate?

Honestly, if you are gonna do track days, just go ahead and get some better brake pads, I love my HH sintered (even though not street legal, though I use them on street). That will take the pad guesswork out of the equation. Also, you could go ahead and throw in some DOT4 brake fluid and flush your system. Both of these are good to do before you start going fast at track days anyway and are relatively cheap.

Besides that, the only other thing I can think of is your rim might be bent a bit and you don't notice it until most of your and your bike's weight is on the front wheel. I can't imagine this being a suspension problem, but you could always message Dave Moss from Dave Moss Tuning and throw it by him. He wouldn't charge ya for a Facebook answer I don't think.

Post a picture of your front tire. That would tell us if you have front rebound at some crazy amount or even if your compression is way off. Also, throw a zip tie on your front fork and go do a 60-0 HARD brake and see if you are bottoming out your forks.

- Donnie
 
#38 ·
I personally would avoid the pressure washer......

The buttons between the hub and rotor provide an expansion joint to allow the rotors to expand when they get hot from braking. Iron rotor, aluminum hub, and whatever other metal the buttons are..... All with thin gaps between them, that trap moisture. Forcing more water in there is a bad idea, IMHO.

A near certainty that they will eventually corrode together and eventually bind up. If they cannot allow equal motion out, then back in when the rotor cools, that's what causes warped rotors.


Breaking the buttons free by rotating them has been described here in the past; doesn't take a lot of time, money, or specialized tools. You just need a bit and bolt that barely fit through the hole in the button so you can clamp onto just that button, and brake cleaner. Tighten enough, so that when you twist the bolt, the button follows. Soak the gaps around the button with the cleaner, to flush out whatever crud is in there. Work them one at a time, you'll know when they behave the same.
 
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