Unusual Brake Shudder on my 08

[AVGeek]

After searching through the forum, I have not seen anyone else with the same issue I have been noticing lately. I am using my 08 as my daily commuter (yes, even during the summer in Vegas). My commute each way is about 31 miles. I don't really notice the issue in the morning, but on the way home in the afternoon it's really noticeable. Most of my ride is freeway, with very little traffic to slog through. What I have been noticing is that after running up most of the road, when I apply the brakes, I get a vibration or shudder coming through the bars. It is definitely the front brakes, as when I release them the shudder goes away, and I do not feel it when I apply only the rear brake. It only happens the first time I apply them after running at highway speeds for a while, with subsequent stops the vibration seems to go away.

The brake system is stock; the bike has over 16K miles and the front tire was replaced at around 13K. It doesn't feel like the ABS kicking in, more like a direct metal to metal, harsh feeling. I have checked the pads and they have plenty of material left. I am at a loss for anything else to check, and would appreciate any insight!

 

[johnny80s]

Had something similar happen on my VFR. I had over lubed the chain and got some oil on the pads. when I hit the brakes it would shudder. Sold the bike before I cleaned it off.

 

[kaitsdad]

You might also check for a warped/bent rotor -

Do you get any pulsating through the brake lever?

 

[FJRay]

+1 on what Hal said. A warped or damaged rotor will do it and will usually get worse with heat. It is real easy to damage a rotor when changing a tire. Did this start after your last tire change ???

 

[FJRBluesman]

You might also check for a warped/bent rotor - Do you get any pulsating through the brake lever?

Possibly
The other thing it could be as Johnny80's said, there could be some sort of very slight goo on the rotors/pads and the brakes grab, then slip, then grab then slip again, repeat as needed. Or a combination of both.

The cheapest way to diagnose this is a new set of pads and really clean the rotors well with some sort of cleaner, I won't recomend anything as what I would use someone else say, nah. Well, OK. Say laquer thinner, brake cleaner, contact cleaner, or other nasty chemical that won't leave residue or oil behind, etc. Never use turpintine/paint thinner as it's petroleum based.

If that doesn't do it, it maybe time for new pads and rotors, not cheap. My fornt brake post. I got mine at MRCYCLES.com.

 

[AVGeek]

I was thinking warped rotor as well, since the overall ride quality is not as smooth as my 04 was. I originally attributed that to the difference in tires (Bridgestones on the 04 versus Metzlers on the 08). It started about the same time as the tire change, but I had Cycle Gear re-check the balance (thinking that the issue) and did not see any runout on the discs, and the balance was fine.

Looks like I'll be running the front tire over to the stealer instead to check for a warped rotor:angry:

 

[FJRay]

I don't know what the spec is for a gen2 but for my 03 the run out is .004. You won't see that unless a dial indicator is used. If the rotors were removed for the tire change then there is a procedure for making sure they are correct. Its in the book.

 

[AVGeek]

I took the wheel over to the dealer yesterday; they checked the balance of the wheel, and it was off. There was no measurable warping in the rotors.

From another thread on Galfer brakes, I decided to clean up the calipers and rough up the original pads. When I took it for a test ride around the area, it seemed to be a lot better. I'll know more tomorrow on the ride into or home from work, although I did notice an improvement in the overall smoothness in the ride. At this point, I'm chalking it up to glazed over pads.

 

[AVGeek]

Final update (forgot about this thread for a while)

Turns out I had a bad wheel bearing, which the dealer attributed to over tightening the front axle. Had the bearing replaced, and was cautious in torquing the front axle fasteners, and no problems so far.

 

[Jeff Q]

I have been having the same issue. Was waiting no new tires to trouble shoot farther...Will have to check the wheel bearings...I too went though all the steps of scuffing the pads, checking the rotors and fond them within spec...Did spin the tire over and did not really hear or feel anything with the wheel bearings but I will check them again...

 

[AVGeek]

I couldn't feel anything wrong with the bearings either, it was heating them up that really did it. Once they were pulled from the wheel, it was much easier to feel the damage.

 

[Jeff Q]

New bearings and seals on the way, it is worth a try...Thanks for sharing.

 

[Fingerflicker]

My problem just started Wednesday, felt like I had a chunk of tread missing on my front tire. When my ABS light came on the next day I though maybe a small stone got into the anti-skid sensing unit, but there was no damage. I figured it had to be a bad bearing. When I seen your post I ordered new bearings and am having them installed now. Thanks for sharing.

 

[Fingerflicker]

Local shop replaced my front wheel bearings and found one to be seized in the cup on the wheel. They had to take it out in pieces. All is better now.

 

[FJRless]

One typical cause of brake shudder is either excessive rotor runout or warpage. The other is incompatibility between the pad and rotor. Seems unlikely I know but believe it. The first is easy to check with a dial indicator. The other you would have to know the history of repairs (aftermarket pads/rotors, etc.) or replace one or both. The grease theory sounds plausible but I've never heard of it. A can of brake cleaner would eliminate this as a possibility.