vibration problem (Full Version)

CBR Forums >> Past CBR Models >> CBR 900RR

vibration problem

  

CBR900RR -> vibration problem (5/5/2008 10:22:36 AM)

hellow, got a 1999 mod cbr900rr with only 24.000km on the clock :)
but i got vibration in the front brakes, the wheel is ok and i just exchange the front brakedisks
but still vibrate when breaking, first owner did forget a lock on the breake disk when trying to drive off, can that have hurt the breake calipper/shock-absorber ?

eny ideas what to do ?

  
stynkmonkey -> RE: vibration problem (5/5/2008 1:55:06 PM)

When you swapped the rotors were they for new ones or some used ones off ebay, and did you swap the pads out as well. If they were not new the rotors might be warped and if the old ones were warped the pads might have worn funny and might not seat right in the new rotors.

CBR900RR -> RE: vibration problem (5/6/2008 12:44:41 AM)

the old disks was warped for some time
the new breakedisks where used ones, but did buy them from a mc dealer, he told me they was NOT warped, no did not buy new pads as they are almost new
wont the pads "asjust" them selvs to a new set of disks ?

if not can i sand them down my selv so they become even ?

CBR900RR -> RE: vibration problem (5/13/2008 4:30:15 AM)

i have taken all apart and change the front damper oil becouse of a bad oil-ring
front wheel bearing,stearing bearing,caliber,damper looks fine
pads looks almost alike, but not 100% even
with the front brake half inn at slow speed i can feel : brake-relese-brake-relese
feels like when the wheel har gone one time around the brake "takes" harder at "one" point

is this still typical for a bad brake disk ?
talked to the mc-shop again and he said he did measure brake disk's before sending and they was 100% ok

plz help me, going to tae track soon and got to get this sorted!!

jpramondon -> RE: vibration problem (5/13/2008 6:03:15 AM)

2 things that ban be easily done are :
1)
- put your bike on front and rear stands
- un bolt your calipers
- make your fonrt wheel turn with your facing the tire
- look if they're not bent somewhere

2)
- don't put your bike down the stands :)
- with one hand on the tire to prevent it from turning, use your second hand (as a human beeing you should have 2) to tug the disk on a radial move (from the center of the wheel to the rim edge). In other words, make as if you whished to remove the external part (steel) of the disk from the internal part (the holder).
- turn the wheel a bit and try again. You should do this at every disk nut (the O ring between the steel and the holder).
If the external part of the disk moves, then it's fried and causes a vibration and even a nasty dribble ...
That 2nd step is often forgotten when checking disks.

Try these and let us know.
BTW, do you have braided lines ?

J

jpramondon -> RE: vibration problem (5/13/2008 6:08:33 AM)

I've read your explanation a little late mate.
What you describe might also be caused by a bent front axle.

quote:

ORIGINAL: CBR900RR

i have taken all apart and change the front damper oil becouse of a bad oil-ring
front wheel bearing,stearing bearing,caliber,damper looks fine
pads looks almost alike, but not 100% even
with the front brake half inn at slow speed i can feel : brake-relese-brake-relese
feels like when the wheel har gone one time around the brake "takes" harder at "one" point

is this still typical for a bad brake disk ?
talked to the mc-shop again and he said he did measure brake disk's before sending and they was 100% ok

plz help me, going to tae track soon and got to get this sorted!!

CBR900RR -> RE: vibration problem (5/13/2008 11:07:15 AM)

quote:

ORIGINAL: jpramondon

I've read your explanation a little late mate.
What you describe might also be caused by a bent front axle.


np m8
you think a forgotten disk lock when taking off on the bike cud bend the front axle ?

jpramondon -> RE: vibration problem (5/13/2008 12:51:10 PM)

quote:

ORIGINAL: CBR900RR
np m8
you think a forgotten disk lock when taking off on the bike cud bend the front axle ?


you'd be suprised how some parts are prone to bend ... a simple forgotten disc lock is usually however not that bad.

There are some other possibilities :
- have you fitted braided lines ?
- do you feel your "brake/release/brake/release" sensation in the brake lever ?

J

stynkmonkey -> RE: vibration problem (5/14/2008 5:16:27 AM)

Have you also made sure the wheel is balanced and somewhere along the way you didn't drop a wheel weight? 

jpramondon -> RE: vibration problem (5/14/2008 7:07:40 AM)

quote:

ORIGINAL: stynkmonkey

Have you also made sure the wheel is balanced and somewhere along the way you didn't drop a wheel weight? 


That's a good idea too, even though he'd certainly feel it when not braking.

J

txn_driver -> RE: vibration problem (5/14/2008 4:59:34 PM)

I have braided lines on my front and i only feel vibration in the front when i hit them hard, but then again that was when my front fork busted and i didnt realize i was leaking fluid im hoping new front fork seals fix the problem, it was only when i jammed them HARD like stoppie hard or lock up hard.

dinez74 -> RE: vibration problem (5/14/2008 6:22:35 PM)

If the vibration is constant while you are riding, then it is your wheel. If it's only when you apply the brake, the most likely cause is your fork settings. However I recomend you the do what JP had described  above to ensure your brakes are ok. Good luck.


CBR900RR -> RE: vibration problem (5/16/2008 5:38:15 AM)

problem here is that the honda dealer has no mechanic for the moment so i have to try to fix this my self...

no i dont have braided lines
i did check the "disk nut's" and the all are lose,the steel of the disk can "float freely"
the vibration is ONLY there when i apply the front brakes  (200km/h with no brakes and its fine)
with hi speed braking it is a big vibration, but the slower the speed, it goes over to be pulsing or brake/release/brake/release sensation
i did mont a pencil to the shock-leg and both the disk and the rim seems fine when turning the wheel
but if i hold light on the brake and turn the wheel,i can feel brake/release/brake/release
did take the front axel out and it is fine

in my mind it can only be a bad: brakedisk or caliber

what do you think ?

ZRX1 -> RE: vibration problem (5/16/2008 6:51:12 AM)

CBR900RR,

I have to agree with the guys here, and with your last post, it's one or both of the rotors, what you will need to do is remove them. Use a 12 inch scale, one that you know is good and true, like a carpenters square. Lay each of the rotors on a good flat surface and check them as many times a possible between each of the steels, check both if there is any light between the scale and the rotor surface or the scale will rock up and down, then you know the out come. You have a warped rotor or rotors.

Calipers will work or the won't work, if the piston is frozen the brake will either say applied, or back in where it will not come out and push the pad agains the rotor. What you are feeling through the brake lever is a paulsation of the warped rotor, This is because the brake pad and caliper are moving in conjection with the surface of the rotor.

The local dealer doesn't need a mechanic on duty to check them, if you have a warped rotor / rotors I would take them back and show him and would ask for a refund.

I would take them back along with your square and show him where the problem is and that there is warpage.

Good luck and let us know what you fine.

[sm=partyparty.gif]



jpramondon -> RE: vibration problem (5/16/2008 2:01:24 PM)

Couldn't say better than that !
A caliper just applies on the rotor. If you feel your brake lever goes back in your hand then that's because the pads are pushed back by a bent rotor.
I can't remember having bought a bike that had straight rotors (I buy crashed bikes from salvages ...). I can assure you that one can say his rotors are straight when your eyes can't see a bent on them when your wheel is rolling freely (without calipers) with you facing the wheel. Damn, I made it complicated again ...  [&:]

When you say your disks are "floating freely", is this difficult to make them "float" ? If not, then the rings are loose and ... dribble !

Now I should try to stop adding my 2 cents now ... [8D]

J

quote:

ORIGINAL: ZRX1

I have to agree with the guys here, and with your last post, it's one or both of the rotors, what you will need to do is remove them. Use a 12 inch scale, one that you know is good and true, like a carpenters square. Lay each of the rotors on a good flat surface and check them as many times a possible between each of the steels, check both if there is any light between the scale and the rotor surface or the scale will rock up and down, then you know the out come. You have a warped rotor or rotors.

Calipers will work or the won't work, if the piston is frozen the brake will either say applied, or back in where it will not come out and push the pad agains the rotor. What you are feeling through the brake lever is a paulsation of the warped rotor, This is because the brake pad and caliper are moving in conjection with the surface of the rotor.


  

Page: [1] 2   next >   >>

Return to CBR Forum home page or view the Full Version of this page.