Brakes Problem?

[HollywoodBush]

Just checkign with you folks....when I apply front brake to my bike it seems like it surges. Almost like a warped rotor but the rotors are not warped and new pads have been installed and broken in. I can apply a small amount of brake and I can feel the bike jerking. Any ideas?

[Vtec44]

It just started happen out of no where?

[Asian Dave]

Paging CM!!!

[HollywoodBush]

I did not notice the problem when the new pads were installed. I just started to notice it the pass week or two. Not to say it has never happend but I think I would notice something like that.

[Chas4RR]

Maybe you got some foreign substance on your rotors?

[HollywoodBush]

Like what? What would make the rotors not hold a firm grip? I checked the rotors and they seem clean and no damaged from what I can see. I guess I can wash the bike and see if that helps the problem, any other ideas?

The bike just jerks/surges at low speed braking. When I apply front brake at high speed ( like from a freeway ) it brakes fine and no notice if the problem but as the bike slows down and brake is still applied you can feel it.

[NomadRip]

Could be a very slight warpage. If you're not feeling it at high speed, that's gooder. Not real dangerous at low speed, just annoying as hell. If you clean them, don't use brake cleaner on anything other than calipers without pads. Soap and water on the rotors with a scouring pad or wetsand them.

[HollywoodBush]

I just don't know how they got warped....they look fine and worked fine until now. I will try cleaning them with soap and water and see if that helps.

Yeah I usually switch to my rear brake now, when I am at slower speeds.

[AdvSac]

Same thing happened to the set of rotors on one of my rims. I dont know if its just one of the rotors, gotta start playing musical rotors with the known good set. It feels the same, Surging at low speed, and at high speed its just surging so fast you cant tell. Hey, if your gonna buy a new set, i might buy your messed up set if i can figure out its just one of my rotors.

[Chas4RR]

I had the same annoyance after changing pads on my last bike and eventually it started squeeking too. Took some 600grit emery cloth to them and it would help for a while but the pulsing and squeeking always came back so I sold the bike. you might also want to bleed your brakes - if the crossover line going from the junction had air in it then it can cause uneven side/side braking...i think.

[AdvSac]

yeah, your shits warped dude, I got two lines from the banjo, I switched brake pads (due to wear) and it did the same thing, Hit it with a green scotchbrite pad on a high speed, and cleaned the suckers with contact cleaner, no help. Bought second rim with rotors for 150! (STEAL) Problem solved.

[HollywoodBush]

Same thing happened to the set of rotors on one of my rims. I dont know if its just one of the rotors, gotta start playing musical rotors with the known good set. It feels the same, Surging at low speed, and at high speed its just surging so fast you cant tell. Hey, if your gonna buy a new set, i might buy your messed up set if i can figure out its just one of my rotors.


That sounds exactly what it is doing! I was not planning on buying a new set but it looks like I will have too.

[HollywoodBush]

Damn...more money being spent LOL!

[AdvSac]

Tell you what, make me an offer for my extra set, (ones warped, i dont know if two) and you could just come down here and pick em up!

[HollywoodBush]

But what if I got two warped rotors?

[1HardRyder4Life]

im sure you can find a used one for cheap, no?

[Cookiebug79]

Eric, do you have a way to check the flatness of the rotors? Like with a dial indicator?
Check your front tire pressure, and that all the bolts are tight, too.

[HollywoodBush]

I have no real way to check rotors but I have checked tire pressure and bolts.

[HollywoodBush]

What sandpaper or any other material would you use to clean the rotors? I am going to try that first to see if it helps...

[ZMAN]

Eric, do you have a way to check the flatness of the rotors? Like with a dial indicator?
Check your front tire pressure, and that all the bolts are tight, too.

and how would you go about checking the rotor with that dial ind ??

mount the rotor were ??
and dial were ??

[ZMAN]

It DOES sound like warpage

First off
i would take rotors off
make sure ALL buttons have play and are not sticking or something preventing play "assuming there Floters"
use Water and fine grit sandpaper and clean rotors "Both sides"


then take pads off
Use some mid grit sandpaper and clean pads off "renew contact surface"

CLEAN everything especially Pins and springs, dont forget to clean pistons
i use WD40 and some real fine sandpaper
once your all done cleaning and drying

Press pistons as flush and even as you can on both calipers
Install back together

NOW !!
before you go and just pump the master

pull the lever in only about .5in at a time and release
do this until both calipers set the pads properly

If after all this you can still feel the warpage
you pretty much NEED rotors or live with them <-------- not recommended

[Cookiebug79]

and how would you go about checking the rotor with that dial ind ??

mount the rotor were ??
and dial were ??
Is this a serious question or are you just being an asshat? Really?

[ZMAN]

Is this a serious question or are you just being an asshat? Really?

me ................ never :ohno

[Cookiebug79]

me ................ never :ohno
Yeah, that's what I thought.

[HollywoodBush]

What sand paper you use?

[ZMAN]

Yeah, that's what I thought.

But in all fairness how would YOU do it ?? :naughty2

[ZMAN]

What sand paper you use?

400 or 500 grit

[HollywoodBush]

werd okay.

[Cookiebug79]

But in all fairness how would YOU do it ?? :naughty2
how would I do what? use a dial indicator? troubleshoot the brake problem all together? make jello? put it in your butt?

[HollywoodBush]

Another question....what would cause this warped rotor(s)?

[Chas4RR]

Another question....what would cause this warped rotor(s)?

splooge.

[Cookiebug79]

Another question....what would cause this warped rotor(s)?
Heat

[ZMAN]

how would I do what? use a dial indicator? troubleshoot the brake problem all together? make jello? put it in your butt?
all of the above ha ha


How would you use a Dial indicator on the rotor ??
would you leave the rotor on the wheel ??
take it off ??

[ZMAN]

Heat

Fru !!!
thats usually the only thing

Unless ya hit something hard
or
left a wheel lock on it and forgot :doh

[Cookiebug79]

all of the above ha ha


How would you use a Dial indicator on the rotor ??
would you leave the rotor on the wheel ??
take it off ??
Aiiiight, I can think of at least one way on the bike, 2 taking it off the bike. But I have a meeting now until 6:30. I'll get back to you later tonight.

And my jello recipe is amazing.

[ZMAN]

Aiiiight, I can think of at least one way on the bike, 2 taking it off the bike. But I have a meeting now until 6:30. I'll get back to you later tonight.

And my jello recipe is amazing.

I shall try it
and enjoy it :naughty2

[Cookiebug79]

Ok the more I think about it, the more ways I can come up with to do it. A lot of these methods can me combined or varied depending on the fixturing and facilities that are available. Hooray for dial indicators!

http://i39.photobucket.com/albums/e195/bauerj79/OTW/dialindicator1.jpg

Method #1: With the rotor on the wheel - using front stand or block under the frame that allows front wheel to rotate (similar to the picture of the car rotor below)
1. Raise the front on a stand
2. Set up dial indicator mounted to the ground with needle zeroed on rotor
3. Make note of your start point on the rotor
4. Slowly rotate the wheel 1 full rotation
5. Note the amount and way the needle moves.
.......a. In a perfect world with a flat rotor, the needle will not move at all.
.......b. The needle could move positive for a bit and then negative for a bit and then back to center by the time you get it all the way back around. Make a note of that delta. If it's more than the runout spec of a rotor (I think it's something like 0.015" but I'm not 100% sure) you might or might not have a problem and it will need further investigation.
.......c. If the needle moves back and forth a lot, or crosses any value more than twice (once counting up and once counting down), the rotor is warped.

http://i39.photobucket.com/albums/e195/bauerj79/OTW/dialindicator2.jpg

Method #2: With the rotor on the wheel - No front stand
1. Mount the dial indicator fixture rigidly to the front fork
2. Zero the needle on the rotor
3. Make note of your starting position
4. Slowly roll the bike backwards for one full wheel rotation.
5. Note the amount and way the needle moves.

For those of you who would argue that floating rotors would not work with methods 1 and 2, the springs that hold them in place are much stronger than the indicator needle. So the rotor should be centered enough to not move. Regardless, in this case you are looking more at the pattern of the needle's movements as an indicator.

Method #3: Rotor off the wheel, using a spinning fixture for the dial, such as one on a mill (see picture below)
1. Remove rotor from bike
2. Secure rotor by:
.......a. placing in large inspection cone (concave) and adding weight
.......b. place over inspection cone (convex)
.......c. bolting to a mill fixture
.......d. screwing them to measuring blocks
3. Raise the table or lower the indicator to zero the dial.
4. Spin the dial
5. Note the amount and way the needle moves.

http://i39.photobucket.com/albums/e195/bauerj79/OTW/dialindicator3.jpg

Method #4: Rotor off the wheel, using a depth gage and a dial indicator combination - indexing
1. Remove rotor from bike
2. Secure rotor in place same way as method #3
3. Lower the depth gage on to the rotor and zero both it and the dial indicator
4. Raise the depth gage
5. Rotate the rotor a few degrees
6. Lower the depth gage back to zero and note the difference on the dial indicator
7. Repeat steps 4-6 enough times to get a pattern completely around the rotor.
8. Note the amount and way the needle moves.

However, if the thing it badly warped, if you try to lay it on a flat surface you will be able to tell if it's not completely touching the surface all the way around. 1st indication is if it's tippy. If it's not, lay it down, hold it, and try to slide a sheet of paper under it.

[Cookiebug79]

Sorry, I forgot the jello recipe.

1 box of strawberry, watermellon, or orange jello
1 cup of boiling water
1/2 cup of peach schnopps
1/2 cup of vodka
20 2-oz sauce containers DO NOT USE PAPER DIXIE CUPS!

combine jello and boiling water in a bowl
stir in schnopps
stir in vodka
poar into sauce containers
put in refrigerator for a few hours.
shoot and enjoy!

[ZMAN]

Jen
you did Good :thumb

[Cookiebug79]

Jen
you did Good :thumb
Well, it IS my favorite jello recipe...


Thanks Rudy.

[Vtec44]

Daym Jen, :love :love

[HollywoodBush]

I rode today without earplugs and when I hit the front brakes I can hear a noise....I think I need new rotors....Damn!

[ZMAN]

floating rotors always make noise
Also pads make noise
so some noise is normal

[Asian Dave]

I rode today without earplugs and when I hit the front brakes I can hear a noise....I think I need new rotors....Damn!


My GIXXXXXXXXXXXXAR makes noise. More like a ROOOOOOOOOOOOOOOOOOOOOOAR.

New bike FTW!! New payments FTL!!

[HollywoodBush]

I doubt this is normal I know you hear a light grinding noise when pressure is applied to brakes but this was a bit different. Hard to explain...oh well....I am cleaning the rotors this weekend along with the pads. If that does not help then new rotors FTL!

Any suggestions on rotors?

[Asian Dave]

Stock?

Galfer if you wanna spend $$$.

[ZMAN]

Galfer is over priced

EBC great rotors
Pro lite countour is my recommendation they are .5mm thicker and good quality.

[HollywoodBush]

Will they fit like OEM?

[ZMAN]

Will they fit like OEM?

Yup direct bolt on

[HollywoodBush]

werd! thanx...I LOVE YOU SOOO MUCH!

[ZMAN]

werd! thanx...I LOVE YOU SOOO MUCH!

U lub me long time .......

[HollywoodBush]

Damn your right Galfer and Brembo are the same prices, $500 for a set....EBC is about $350

[ZMAN]

Damn your right Galfer and Brembo are the same prices, $500 for a set....EBC is about $350

Told ya
Ohhh and if ya ask someone on this forum
I think they have hookups
can't say his name cause they will MASH me and I would turn into some sort of MISH :lmfao

[HollywoodBush]

LOL damn if you could only tell me his name!

Hey on Brembo brakes can you get bolt-on OEM rotors? I thought you needed to switch out the calipers also?

[ZMAN]

LOL damn if you could only tell me his name!

Hey on Brembo brakes can you get bolt-on OEM rotors? I thought you needed to switch out the calipers also?
All brands have OEM direct replacments

[AdvSac]

Hey hollywood, i played musical rotors and it turns out i got a good L/H rotor, and my R/H rotor is warped.

[HollywoodBush]

I will see this weekend how the cleaning of the rotors go....