Page 1 of 2 12 LastLast
Results 1 to 15 of 16

Thread: Rotors / pulsation / wobbling

  1. #1
    apriliaforum Junkie razteo's Avatar
    Join Date
    Dec 2012
    Location
    SoCal
    Posts
    292

    Rotors / pulsation / wobbling

    Endless posts here about low mileage bikes with wobbling brakes, pulsating lever when braking, etc.
    Same with my DD, 3000 miles on the bike and wobbling when stopping to a light or anything.
    People were talking here about all sort of procedures to improve that, and looks like nothing works except replacing the rotors (expensive).

    This weekend I went to specialized shop and have both rotors straighten and the front wheel. I was trying something that I haven't seen many people doing here.
    Amazing people and technology they use. Is 99% measuring and then using manual presses of different sizes, very cool. They work for Yamaha Racing Team here in US and straighten bike frames, forks and wheels for them, and lots of other things too. They take a bike and put it flat on its side on a special platform and align 4 points on frame on each side to a reference point, and get the frame factory straight in minutes. And many other things, like cool welding, etc.

    Anyway, after almost 3 hours of work, my wheel & the rotors were better then new. The wheel needed no weights balance at all (and this is with my old tire), and the rotors have almost zero variations in height when rotating 180 degree (almost 30 times less then what it was when I brought the bike in). They charged me $200.

    The result: absolutely no improvement in wobbling when braking.
    Unbelievable!
    Last edited by razteo; 02-19-2013 at 12:39 PM.

  2. #2
    apriliaforum prov-nov hpark7's Avatar
    Join Date
    Nov 2012
    Location
    Cornelia, GA
    Posts
    34
    God that sucks... I'm scared to buy any new rotors for that reason. I'm going to check bearings and suspension first to make sure it's none of that.

  3. #3
    apriliaforum Junkie razteo's Avatar
    Join Date
    Dec 2012
    Location
    SoCal
    Posts
    292
    Quote Originally Posted by hpark7 View Post
    God that sucks... I'm scared to buy any new rotors for that reason. I'm going to check bearings and suspension first to make sure it's none of that.
    mine only does it when braking, at slow speed to a stop. Not when braking hard. Everything seems fine when not braking.
    The fact that replacing the rotors is fixing the problem may be the clue.

  4. #4
    apriliaforum expert MARTCO78's Avatar
    Join Date
    Jul 2012
    Location
    London UK
    Posts
    2,094
    Quote Originally Posted by hpark7 View Post
    God that sucks... I'm scared to buy any new rotors for that reason. I'm going to check bearings and suspension first to make sure it's none of that.

    It has happened to me twice over the years and each time I just swapped the rotors for new and it was completely cured - nothing else was touched, in fact I was lazy enough to not even change the pads at the same time as I recall without adverse affect.
    I've never nailed why or how it happens, but both bikes were single disc Hondas, one near the end of the rotor life, one not. I've never had a reasonable explanation as to why, so put it down to a combination of physical and thermal stresses working on material of variable content - something you have little control over.


  5. #5
    apriliaforum prov-nov hpark7's Avatar
    Join Date
    Nov 2012
    Location
    Cornelia, GA
    Posts
    34
    Hmmm, I might just break down and buy some then. Mine does the exact same thing at yours razteo.

  6. #6
    apriliaforum Junkie abarth's Avatar
    Join Date
    Oct 2008
    Location
    Serbia, NS
    Posts
    484
    I had same problem with brake pulsating on slow braking and hard vibrations on high speed braking. Found one interesting thread on RSV section of this forum about same problem with brakes with conclusion that wheel is faulty and was replaced in warranty. Fault on wheel was bad machining of central/axle hole resulting that wheel border and disk central holders osculate in same way. Checked my wheel and found that have exactly same problem. Checking is done by lifting front end, removing brake calipers so wheel can rotate freely and with felt pen positioned firmly on fork rotate wheel by hand and move pen closer to wheel border until it start touching it and leaving mark. Same thing on disk center not the floating part of the disk. If you have this kind of faulty wheel you should get pen marking on 1/2 of the wheel radius and on opposite side of the wheel on other half of radius. Problem solved with buying brembo wheel from 2006 RSV with radial clippers. Only wheels from RSV with radial clippers will fit. In process of finding new wheel found one same as mine but from 09 RSV that had exactly same problem. So be careful if you buying same wheel they are made in china! Look for Brembo or OZ.

    Click image for larger version. 

Name:	2012-12-25_14-01-28_473.jpg 
Views:	24 
Size:	145.7 KB 
ID:	214340
    Last edited by abarth; 02-18-2013 at 05:12 PM.

  7. #7
    apriliaforum prov-nov Rob750's Avatar
    Join Date
    Aug 2010
    Location
    San Francisco
    Posts
    44
    I've posted before about my front brake pulsation. It was frustrating. I had the discs machined, and it still pulsated. I used an automotive type brake disc runout gauge and there was runout. I bought new rotors, there was still runout, although less. It no longer pulsates. Because the discs float on the buttons, its hard to accurately measure runout. It really seem like when I repositioned the rotors on the wheel the runout moved to a new point on the disc, which would suggest the wheel is not perfectly true where the disc attaches. If that is the case, I'll probably need rotors again sometime.

  8. #8
    apriliaforum expert shekel's Avatar
    Join Date
    Mar 2009
    Location
    Roseberry Creek, Oztralia
    Posts
    2,999
    Interesting. My rotors display noticeable runout but I've never had any pulsing, even when breaking sharply.
    Gil
    'Its only rock n roll but I like it....'

  9. #9
    apriliaforum expert High Country's Avatar
    Join Date
    Feb 2012
    Location
    Sierra Nevadas
    Posts
    4,118
    Mine have a pulsating sound (like a summer time insect), but no pulsating feel or wobble. I'm beginning to think it is my floaters squeaking as they compensate for imperfections in the wheel. I shall consider myself lucky.

  10. #10
    apriliaforum Junkie razteo's Avatar
    Join Date
    Dec 2012
    Location
    SoCal
    Posts
    292
    Quote Originally Posted by shekel View Post
    Interesting. My rotors display noticeable runout but I've never had any pulsing, even when breaking sharply.
    Mine you can only feel at low speed to a stop.
    I now worry that if the wheel core is not straight, then is no pint in replacing the rotors. Although I read here that almost everybody who replaced them got rid of the problem. Don't know what to do next.

  11. #11
    apriliaforum expert potere's Avatar
    Join Date
    Oct 2010
    Location
    Monterey CA
    Posts
    3,636
    If you're not in SoCal, since you have someone down there, send your wheel and rotors to Gery at http://www.gpframeandwheel.com/. He will straighten wheels and rotors if they are not out of spec too far. He mentioned to me that sometimes the person who changes your front tire may cause the rotor carrier to be bent if they are careless. Best bet is take your rotors off before having a front tire changed.

    A rotor that is more than 0.0005" out will not be repairable. That is 1/2 of a thousanth of an inch!

    If' you've done everything and still have a problem, try bead blasting the rotor surfaces. It takes about 15-30 min to tape up the rotor so that nothing shows except the rotor surface itself. In any case, you also need to sand the pads with 100 grit to get them nice and clean too.


    I have found that if you clean your calipers with brake cleaner or degreaser while the rotors are still mounted, this can unevenly remove brake pad material from the rotor surface which can then cause brake moaning or judder when stopping. In any case, you should sand the pads also with 100 grit to get them nice and clean too.

    The way you break-in your pads is obviously very important. Do it wrong and you'll get brake judder that you cannot fix without blasting the rotors clean as above.

    The problem is if you are bedding-in technique is wrong, after you clean the rotors and pads, you will more than likely bed them in wrong again. Talk to a brake expert, someone who races or Jeff at BrakeTech to get the right info on bedding in. His website has many FAQ's that are really informative.
    Last edited by potere; 02-20-2013 at 12:09 PM.
    potere - italian for power
    have M1 permit, will travel

  12. #12
    apriliaforum Junkie abarth's Avatar
    Join Date
    Oct 2008
    Location
    Serbia, NS
    Posts
    484
    It is brakes not rocket science. When you put new rotors they have more flexible and easy moving buttons and can compensate oscillations caused by excentrical axle hole on the wheel. And this will last for short time until they get dirty and start to wear out and then problem returns. I tried everything from new pads, wheel balance, progressive spring, steering bearing, switching rotors and nothing helped. Finally new front wheel solved brake pulsation. I didn't see nobody on this forum with OZ wheel complaining about brake vibrations...

  13. #13
    apriliaforum prov-nov hpark7's Avatar
    Join Date
    Nov 2012
    Location
    Cornelia, GA
    Posts
    34
    Maybe wheels, but mine lasted 7500mi, I don't think mine just decided to get out of spec all of a sudden. If they will last another 7500 of hard use and abuse ill be happy. Plus the stock rotors are rubbish in my opinion, sunstar... I buy there sprockets for my dirt bikes simply because they are the cheapest...
    What ever you are, be a good one.
    -Abraham Lincoln

  14. #14
    apriliaforum newb
    Join Date
    Jul 2016
    Location
    New York, N.Y.
    Posts
    17
    I had issues with my 2016 DD with pulsating front brakes after 5000 miles. It was really annoying, especially when braking from higher speeds. I cleaned the buttons several time and the calipers. It did help for a while. The buttons get dirty quickly and keep the disc from floating properly. In the end I changed out the rotors to Brembos. The difference is night and day especially when grabbing the binders at higher speeds. A new set of Michelins didn't hurt either.
    Click image for larger version. 

Name:	IMG_3953.jpg 
Views:	11 
Size:	514.1 KB 
ID:	348793
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	IMG_3953.jpg 
Views:	9 
Size:	403.4 KB 
ID:	348792  


  15. #15
    apriliaforum expert Frodo's Avatar
    Join Date
    Jul 2007
    Location
    Kapiti, New Zealand
    Posts
    2,496
    I had a problem with pulsing brakes, but mainly at low speeds, especially when coming to a stop. My rotors were replaced under warranty but the problem did not disappear. I decided to live with it.
    I removed the forks to replace the oil. The pulsing problem has now pretty much disappeared. I had tried getting the front fork alignment right by loosening the bolts that clamp the front axle, applying the front brake hard then tightening, but this did not remove the problem. So there must have been something associated with the fork tubes' alignment in the triple clamp.
    Anyway, an annoying problem has now disappeared.
    Frodo
    2015 Shiver
    New Zealand

Page 1 of 2 12 LastLast

Similar Threads

  1. Pulsating Rotor Thread.
    By Fox Fader in forum RST1000 Futura (all years)
    Replies: 6
    Last Post: 03-08-2010, 08:32 AM
  2. Brembo Rotors Redux
    By jng1226 in forum RSV1000 Mille, Mille R, and Mille SP (1998-2003)
    Replies: 5
    Last Post: 06-17-2003, 08:53 AM
  3. Brake tech rotor
    By NCRSV in forum SL1000 Falco Forum (all years)
    Replies: 2
    Last Post: 03-12-2003, 10:13 AM
  4. Brake rotors
    By UnsavedOne in forum SL1000 Falco Forum (all years)
    Replies: 3
    Last Post: 02-11-2003, 11:47 PM
  5. Full Floating Rear RSV Rotor...Falco guys, take note!
    By micah apriliaforum com in forum SL1000 Falco Forum (all years)
    Replies: 4
    Last Post: 12-23-2002, 03:31 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •