rotor pulsation

[standout]

Just bought a new bike this year and with the great weather lately finally getting some miles on it. I know the rotors are warped because the handlebars shake when i apply the front brake. My question is can this do any other damage like to the wheel bearings or steering head bearings. Bike is a 2004 cbr 600rr.

[MidgetTodd]

Could be the bearings and not the rotor doing it too

[standout]

it only does it under braking and only under a certain amount of pressure. if i use it lightly i can actually hear the pads rubbing/ hitting and skipping but it won't make the bars shake. if i apply them hard enough it does.

[Tomcat0403]

Get new rotors asap, I had that happen to my rear brake and when I had to apply hard rear brake the ass end got squirrely on me, which didn't help my situation.

[dbonehead6]

i agree...get that taken care of asap before it becomes a serious proplem!

[Harb67]

I'd fix it as soon as you can. No sense in ever having your brakes be a liability considering how extremely important they are.

[tomato_racing]

I'll keep an eye out on WERA for ya! Should be pretty cheap for stockers...

[Funjunkie]

Just a thought.. I had a bike that did the same thing. it was like a jackhammer at hard braking. It wasnt warped rotors at all. It was dirty spools in the rotor. If the spools that hold the outer ring on a floating rotor are too dirty the rotor wont "float" it acts like a solid. Take a toothbrush, soap and water and some kind if tool to wiggle the spools around and scrub the shit out of them to make sure they have movement. I took the rotors off the wheel and scrubbed them in the sink, but thats not necessary...I even put a tiny drop of 3 in one on each spool. I got mixed feedback on that part, but i wiped it down a lot to keep any from running out on the braking surface...try this first before you drop the coin on new rotors. It worked for me. Good luck.

[ironbuttwannabe]

Just a thought.. I had a bike that did the same thing. it was like a jackhammer at hard braking. It wasnt warped rotors at all. It was dirty spools in the rotor. If the spools that hold the outer ring on a floating rotor are too dirty the rotor wont "float" it acts like a solid. Take a toothbrush, soap and water and some kind if tool to wiggle the spools around and scrub the shit out of them to make sure they have movement. I took the rotors off the wheel and scrubbed them in the sink, but thats not necessary...I even put a tiny drop of 3 in one on each spool. I got mixed feedback on that part, but i wiped it down a lot to keep any from running out on the braking surface...try this first before you drop the coin on new rotors. It worked for me. Good luck.

+1 Also check your front tire. If it is cupped/scalloped bad this will cause vibration if it is really bad

[John]

while warped rotors and/or tires would be the first place to start looking it COULD be any number of things...

warped rotor, bad tire, bent axle, loose caliper bolts, sticking or otherwise damaged caliper shafts, damaged wheel or wheel bearing...

as for the question, will it do any damage... hard to say really. it definitely isnt helping anything, i can tell you that.

Edited March 14, 2010 by John

[Cheech]

If replacement stockies are not available (or too expensive) you might want to consider picking up a pair of Alth front rotors. I bought my 03 with the knowledge that the front rotor was slightly warped, and picked up a set of Alth's from oncycles.com for about 180 all-in. Great performance. Just checked oncycles and they are sold out of the Honda's (just Yamahahahas and Kawi's) but I'm sure someone else has got them somewhere.

[serpentracer]

everyone is blaming everything except one thing that is known to cause pulsations that no one realizes it,

a slick spot on the rotor surface from a pad melting to it.

this happens if someone didn't properly break in the pads and came to a full stop with the rotor really hot.

the pads will leave a film on the rotor surface so every time it passes through the pads it slips causing a pulsation feeling.

if your rotors were warped, you will have a soft brake lever at first because they will push the pads away from the rotor too far.

first check the rotors to be sure they have no run out etc. if they are straight then buy a rotor hone to recondition your rotor's surface and then sand your pads flat. to do that remove the pads and lay them pad side down on a 100 grit piece of sand paper on a perfectly flat surface and rub them in a figure 8 pattern until they look sanded on the entire face of the pad. then use this hone to put the factory scratches back in the rotor and remove all traces of the old pad glazing.

http://www.flexhone.com/

here is a set of instructions to properly bed in a set of new pads to eliminate this problem.

http://www.zeckhausen.com/bedding_in_brakes.htm

I copied this from another site,

Failure to follow these procedures may result in brake judder, excessive noise, or other difficulties in bedding-in the new brake pads. The pads need a fresh surface to lay down an even transfer film. Residue from the previous pad compound on the surface or an irregular surface on a used rotor will cause the pads to grip-slip-grip-slip as they pass over the rotor surface under pressure. The resulting vibration will cause noise and telegraph vibrations through the suspension and steering wheel. This vibration is known as brake judder or brake shimmy. This is typically caused by an uneven transfer film on the rotor surface or an uneven surface on the rotor not allowing that transfer film to develop evenly. This is often misdiagnosed as a warped rotor.Bedding-in new pads and rotors should be done carefully and slowly. Rapid heat build up in the brake system can lead to warped rotors and or glazed brake pads

Edited March 14, 2010 by serpentracer

[standout]

Thanks for all the replies/ideas. I'm gonna try cleaning the rotors, and resurfacing them first before I replace them. I just wanted to make sure it couldn't screw anything else up on the bike.

[Cheech]

everyone is blaming everything except one thing that is known to cause pulsations that no one realizes it,

a slick spot on the rotor surface from a pad melting to it.

this happens if someone didn't properly break in the pads and came to a full stop with the rotor really hot.

the pads will leave a film on the rotor surface so every time it passes through the pads it slips causing a pulsation feeling.

if your rotors were warped, you will have a soft brake lever at first because they will push the pads away from the rotor too far.

first check the rotors to be sure they have no run out etc. if they are straight then buy a rotor hone to recondition your rotor's surface and then sand your pads flat. to do that remove the pads and lay them pad side down on a 100 grit piece of sand paper on a perfectly flat surface and rub them in a figure 8 pattern until they look sanded on the entire face of the pad. then use this hone to put the factory scratches back in the rotor and remove all traces of the old pad glazing.

http://www.flexhone.com/

here is a set of instructions to properly bed in a set of new pads to eliminate this problem.

http://www.zeckhausen.com/bedding_in_brakes.htm

I copied this from another site,

Failure to follow these procedures may result in brake judder, excessive noise, or other difficulties in bedding-in the new brake pads. The pads need a fresh surface to lay down an even transfer film. Residue from the previous pad compound on the surface or an irregular surface on a used rotor will cause the pads to grip-slip-grip-slip as they pass over the rotor surface under pressure. The resulting vibration will cause noise and telegraph vibrations through the suspension and steering wheel. This vibration is known as brake judder or brake shimmy. This is typically caused by an uneven transfer film on the rotor surface or an uneven surface on the rotor not allowing that transfer film to develop evenly. This is often misdiagnosed as a warped rotor.Bedding-in new pads and rotors should be done carefully and slowly. Rapid heat build up in the brake system can lead to warped rotors and or glazed brake pads

Hell of a good idea.

[serpentracer]

Thanks for all the replies/ideas. I'm gonna try cleaning the rotors, and resurfacing them first before I replace them. I just wanted to make sure it couldn't screw anything else up on the bike.

make sure you check them first.

it's simple. you can do it with a pencil or plastic pen etc

often if you spin the wheel you can see the rotor runout.

using a pencil hold it against the fork tube and put the point against the rotor.

now spin the wheel by hand and watch the point on the rotor. if it moves off the rotor or pushes the pencil in your fingers away from the rotor then you know it's warped. ( I call this a poor mans dial gauge)

[redkow97]

when I had to apply hard rear brake the ass end got squirrely on me, which didn't help my situation.

were you in gravel or something? Unless the road is shit, I hardly touch the rear brake. Rear brake does nothing if the rear wheel is off the ground.

[wrillo]

were you in gravel or something? Unless the road is shit, I hardly touch the rear brake. Rear brake does nothing if the rear wheel is off the ground.

I know its been a couple years since I took physics, but I'm pretty sure you can stop faster with two wheels on the ground.

[standout]

well i tried all the suggestions above and the problem is diffinetly better but still there. I also noticed today that the handlebars actually move forward and backwards as i'm braking. didnt know if this could be an indication of another issue? The bike does have a gpr steering stabilizer that of course i am very unfamiliar with. It also has driven clip-ons wich eliminates the weighted bar ends. I have a bid on some rotors on ebay. we will see how this goes.

[serpentracer]

you might have loose steering head bearings if they are moving. but I would think you should be able to feel it clunking.

did you eyeball the rotors to see if they are straight...and honestly, did you scuff up the rotors with a tool or just some sandpaper?

you should be able to find the 3M roloc disc rotor resurfacing kit at a local auto parts store if you don't feel like ordering a rotor hone. they do sell them at some motorcycle shops.

http://solutions.3m.com/wps/portal/3M/en_US/Marine/Home/Products/Catalog/?PC_7_RJH9U5230GE3E02LECIE20S4K7_nid=GSSXMHGGC5gs4CCRDFQ26Jgl2KX0K0NXS8bl

the most important part is getting those discs clean.

here is some other stuff to look into,

http://www.braketech.com/index.php?option=com_content&view=article&id=58:brake-judder-and-wheel-binding&catid=17:tech-talk&Itemid=69

they also sell the rotor hone,

http://www.braketech.com/index.php?option=com_content&view=article&id=83&Itemid=100

Edited March 18, 2010 by serpentracer

[John]

I know its been a couple years since I took physics, but I'm pretty sure you can stop faster with two wheels on the ground.

i think what he is trying to say is the harder you use the front, the less effective the rear becomes...