I'm getting desperate guys. I'm leaving for the longest ride of my life in 1.5 weeks. I noticed coming back from Reno that my high speed shudder is getting worse. The symptoms are as follows:

WHen I come to a complete stop under gentle braking I notice the slightest pulsating sensation from maybe 10 MPH down to 0. At speeds above 85 or so when I hit the front brakes I get a pretty healthy shudder. I'm pretty sure the shudder is bad enough to cause me problems if I'm in a corner at those speeds and hit the brakes.

So far I've checked the Rotor runout. Service Limit is .012, I'm at .003" one side and .004" the other.

Front Wheel Radial and Axial runout is less than .010". Service limit is .080"

Front Axle runnout is about .002. Service Limit is .008.

Everything is pointing the the Rotors except the fact that I'm well within spec. I've got plenty of Rotor left also.

I pulled the front Calipers off and made sure they float freely. One side moves a little more freely than the other but I don't think I've got a problem there.

Steering Head Bearings where just changed last year and I've got no decel wobble.

I don't think the Tire Balance is it either as it did it on my last tire also.

I'm real hesitant to go blow $350 plus on new rotors unless I'm 100% sure thats the problem. Short of pulling off XXMAN's Rotors (if he'll let me) and put them on my wheel and try it out can any of you suggest something I may have missed?

Please? If I order Rotors within the next few days I may get them in time for my ride but the $$ is gonna hurt right now.

brake cleaner,,,,might be something on the rotor that will not burn off.
had that happen with antifreeze leak that sprayed on the rotor and could not get it off till i changed the pads and brake cleaned the rotors.
just a thought.
hope it helps.

Maybe check pad-to-rotor clearance against specs, to see if only one caliper is doing the work.

hit any potholes? tire radial runout look good? any vibes around 75ish?

+1 brake cleaner

New rotors? There has to be someone who bought those bling rotors from the group buy that has a set laying around. :D

i have a early set you can try

Have you checked the rear rotor as well?

What about the rotor thickness? even?



slow down :P

I read this in one of the cycle mags awhile ago.

It IS your runout of .004. Honda gives a high warp spec. so they don't have to pay for a lot of rotors under warantee.

You WILL feel warpage of .004 or worse.

Didn't check the rear. I have no issues when I just hit the rear. I guess it doesn't put enough force on the front to cause my shudder. Although, I've not tried rear only from 90+. I'll give it a shot tomorrow. I'll also do the Brake Cleaner thing. XXMAN has agreed to let me put his Rotors on my bike tomorrow and I'm keeping my fingers crossed that it's not rotors. If it is I may be begging for a quick by from one of you guys for a good set of used.

trurotor2, you may become my best friend :)

Didn't check the rear. I have no issues when I just hit the rear. I guess it doesn't put enough force on the front to cause my shudder. Although, I've not tried rear only from 90+. I'll give it a shot tomorrow. I'll also do the Brake Cleaner thing. XXMAN has agreed to let me put his Rotors on my bike tomorrow and I'm keeping my fingers crossed that it's not rotors. If it is I may be begging for a quick by from one of you guys for a good set of used.

trurotor2, you may become my best friend :)

Don't swap rotors, if you are going to go through the hastle, just switch the whole front and try it. Atleast you will be narrowing it down.

I guess if I was in a real investigative mode and had a few minutes, I might swap the pads from caliper to caliper and see if that changes anything.

Borrowing a front wheel is probably the easiest to isolate it to calipers/rotors/wheel.

If it still does it with the different wheel, I would look at calipers/pads/steering head. If it doesn't, I would take a closer look at your rotors/tire/wheel/forks???

MaXX

Didn't check the rear. I have no issues when I just hit the rear. I guess it doesn't put enough force on the front to cause my shudder. Although, I've not tried rear only from 90+. I'll give it a shot tomorrow. I'll also do the Brake Cleaner thing. XXMAN has agreed to let me put his Rotors on my bike tomorrow and I'm keeping my fingers crossed that it's not rotors. If it is I may be begging for a quick by from one of you guys for a good set of used.

trurotor2, you may become my best friend :)

I didn't realize there is a Pad to Rotor Spec for Gap. What is it?

pm when your ready :wink:

How the hell did I get 3 of the same posts?

Mac, don't say the F" word. A Fork problem is my BIGGEST fear as I'm sure that would get real costly since I know my Springs/Seals and Oil level is good and I don't know what the hell the problem could be with them. Nor do I know how to go about isolating what the problem with the Forks may be.

Maybe I will just start with the Wheel. If it goes away then I'll swap Rotors only.

trurotor2


Hopefully I'll know more tonight. Thanks.

So, I go to XXMAN’s place since he graciously allowed me to tear his bike apart to help diagnose mine. Great guy that Rob. The series of events are as follows:

I check runout on one of his rotors while on the bike just for the hell of it. He’s got a little more runout than me. Maybe .006” total compared to my .004”

I pull his Rotor and put it on my wheel. Go for a spin and the shudder is still there.

I put his Rotor back on his Wheel then put the whole enchilada on my bike. Go for a spin, still shudders.

I put everything back together, take his bike out and find out his has a shudder also, not nearly as bad as mine but it’s there.

The thing that confuses me more than anything is he has more Rotor runout but less shudder. What kind of runout do you guys that have shudder free high speed braking have on your Rotors?

I’m going to snug up my Head Bearings tonight to see if by chance it helps. I put Tapered Bearing in last year.

I’m getting real confused about the shudder thing now. I can’t imagine we both have a Fork issue. His are all stock and have never been opened up as far as we know (he bought his used also). I’ve got fresh Fork Oil (7.5 wt) and TD 1.1 Springs. I’ve got EBC HH Pads with about 1500 miles on them. I had the Shudder on my previous set of Galfer Pads. It’s been a while but I think I had the Shudder has been there for the last 3 sets of front tires, 2 sets of pads and before I had my Steering Head Bearings replaced.

I don’t typically cruise around at speeds over 85 or so (where my shudder starts) but it happens on occasion (especially when Slabbing with CBR-RR-XXCESS across Nevada). With a new Track opening here at the end of this year I know I’ll be spending some time at 150 or better needing my front end to work properly in order to stay alive.

So I ask you this, “What the hell do I do if/when I find out snugging up my Head Bearings does not fix my problem?

Well I've always thought that if you have a problem with the front of the bike, look at the rear. Perhaps wheel bearings or swingarm bushings? Put it up on the stand and yank the rear around and see if you have any play.

have you tried different tire pressures
start at the top and drop a lb at a time

I'll check out the rear and the tire pressure as I'm purley grasping at straws now. Thanks.

I bet it is in the rear proportion valve that feeds front fluid to the back brakes that you are feeling
try stoping with just the front and then just the rear and then both at the same time equalyand see if it changes the shudder.

Will do.

I’ve paid close attention to front only vs. rear only and rear only does not produce the shudder. I’ll check out both at the same time closely tonight.

Thanks.

What kind of tire do you have up front? Could be a belt moving around.

Not Metzlers I hope. I heard about some problems with the Z6.

Unfortunately this has been going on for a few sets of tires not. Avon’s and the current Pilot Roads.

I am really really REALLY hoping that if I snug up the Head Bearings it goes away but I’m usually not that lucky. I’ve got a Spring Scale from work that I’m going to use in hopes of getting the tension set per the Service Manual rather than by feel.

I'm about 80% sure it was the freaking Head Bearings. Thats pretty much the last thing I expected and they are a year old and I adjusted them myself (HA!) and I've never had lose bearing behave like that before. I snugged them up a bit and it seems better. I'll know for sure this weekend when I get time to frequent 100+ to try them out. I didn't have time to get far enough away from town tonight. I'm sure keeping my fingers crossed.

Thanks for the help guys. I really appreciate it. :thumbsup:

XXMAN, if you read this and I'm right about it being fixed lets plan on doing yours soon.