Hey bmb408, that is an interesting solution. I had the same problem, but Yamaha came up with drilling the fender mount points and installing rubber grommets. This has done the same thing by eliminating the vibration coming up from the brakes. It isolates the fender that has been to source of the vibration everyone has been feeling. Yamaha was going to write a TSB about this, but I have not pursed it after they fixed my Warrior.

 

I've got the same problem. I'm going to try your solution. Thanks for posting it.

 

mine comes and goes... however, when its here- its fvcking annoying! what i DID realize is that after i wash my wheel (sponge/hose/blower) and spray the front brakes/rotor off, the vibration is GONE for a while. i always blamed my vibration on a build up of brake dust.

 

Great post bmb408 , that is very annoying when it happens, the idiots at my local dealership heard it one day when i pulled up , i could even walk the bike and kinda make it do it with just the right amount of lever pressure , they couldnt figure it out and called yamaha , after a couple days i called them and they (idiots) said it must be my mini fairing and wanted to take all that off and try it , im not a mechanic but i knew that wasnt it, anyway im certainly gonna try your solution , again thanks for the scoup .

 

Since the heat has been climbing up near 107 these days, my front brake has become a safety hazard with the oscillation in the front end. I'm heading out of town for three weeks so I dropped the bike off at the dealer. I'm having new pads, bleed the lines, and steel braided lines put on while I'm gone. If that doesn't do anything for me, then I'll give your suggestion a shot. Thanks for the post.

 

Good post! I'm gonna give it a try!

 

another thing that stopped mine was a set of chrome disc from cycle image.
looks good to.

 

Great post. I've often wondered why I heard a vibration when the front brake was applied but hadn't pursued it. You probebly just saved me lot's of time and money.
Thanks, Steve

 

There's no TSB on this yet? They used my bike to come up with the rubber grommit solution in Summer '02. If you search for "Brake Chatter" you'll find the thread I started on the old Delfi/Warrior forum and brought here with me.

Scarman - You'll be wasting your time. Just have them do the fender thing and it will go away. we tried all of that and new rotors without success.

NJW

 

Are you guys bleeding your brakes during all this work? Make it a habit if you're not. I never had the chatter -ever, but got to experience it first hand on VR-4's bike several weeks back. All I can say is, WTF!
What is confusing is why there's so much oscillation in the lines in the first place. Dangling the lines does not seem to be addressing the cause of the problem only eliminating an obvious symptom. Just my .02c worth.

 

Hey bmb408, THANKS!!! I'd tried everything and still had that fricken vibration. I did what you suggested and it worked! I don't quite understand why it works but it worked instantly. YOU ARE THE MAN!!!

 

Ok...here's what I just did two weeks ago. I had the whole bike apart before star days. When putting it back together, I remembered that god awful vibration in the front brakes. So when I reinstalled the front end on the bike, I reversed the rotors and rotated them to the opposite side. I have 900 miles on it to star days and back and not one vibration since the swap.

What do you make of this JP?

 

Since you guys saved my ass, I'll reopen this topic. Like everybody else says, the chatter was driving me nuts. I even had several hard stops leaned over that I thought were gonna spill me, cause the front end was dancing across the pavement. Changed the brake fluid, changed the brake pads, even got yamaha to give me a set of new rotors. Nothing worked.

I read this post, and the next morning took off my front fender and took a ride. NO VIBRATION! Oh my god, now I can ride fast again!

I remounted the fender with some homemade rubber washers made from 5/8" diameter o-ring cord, and loosely remounted the fender with blue loctite.

It kills me that obviously yamaha knows about this problem, and they still send me new rotors. Great internal communication.

Thanks again everyone.

 

Removing the brake line bracket or isolating the fender with rubber grommets is a bandaid fix.

The source of the problem is rotor run out. The calipers on the front are fixed, that means non floating. Any runout in the rotor is instantly transmitted to the caliper pistons & brake lines as the caliper pistons are moving in & out trying to follow the rotor.

The shop manual calls for .004 runout MAXIMUM.

The proper fix is to score a dial indicator & check the runout. Check the outside & inside of the disc surface. IF it is more than .004 try indexing the rotor on the hub.

TO index the rotor. Mark the hub & rotor at one bolt as a reference. Record your runout reading. Remove all the rotor bolts & rotate the rotor one set of bolt holes clockwise. Reinstall the bolts & check the runout again. Continue untill you have made the full circle. If the .004 maxium runout cannot be achieved replace the rotor or as Darkstar stated try swapping them side for side then re index them.

IF the correct runout cannot be achieved the rotor needs to be replaced or the wheel may have to be machined or replaced.

 

so your saying some floating/semi disc up front is a cure option too?

 

These are fully floating discs on this bike. My runout was only at .002" when it chattered like ****. My new rotors are at .001" and they chatter with the fender hard mounted. This has had me scratching my head for a long time, but now I know that the brake system emits a vibration which excites the front fender. The fix (for me at least) is to isolate the fender from the vibration.

 

nm my bad - kept thinking they where solid disc til this morning when i went out and looked...

 

Churchkey, with all due respect I think you are wrong on this one.

I am pretty sure that the root cause to this problem is resonance in the friction between the pads and rotor, with the movement being transmitted through the front fender and back into the brake lines. This is why the problem disappears after a few hard brakes at speed, washing the bike, at certain temperatures, when it rains, or whatever, because that changes the friction between the pads and rotor. Wouldn't have any effect on rotor runout, would it?

Also, if it would be rotor runout, wouldn't the vibration follow the front wheel rotating speed? It doesn't, the vibration is about the same regardless of speed. The front wheel can turn at anywhere from two or three times per second to once per two or three seconds, and the brake still vibrates at a constant rate (somewhere around 10-20 Hz, right?).

IMHO, of course.

 

MNZ- With all due respect back at you I am not wrong on this one.


We beat this subject to death when the Warrior first hit the street & the fix for many was to get the rotors to run true. Warriors use the R1 pads which have a heavy metalic content & need to be beded in properly.

Hard high speed braking rebeds the pads.

Brake pads tend to retain/absorb water after a rain ride or wash or even sitting outside over night when its damp & are effected for the first few stops which can cause noise or chatter untill the pads get hot.

 

Well, as I wrote, how come the chatter doesn't follow the rotation of the front wheel (or atleast the rotation speed)? It would, if it was caused by rotor runout, wouldn't it? Also, with the frequency of the chatter versus the lowest rotation speed of the front wheel where it can happen, there are several dozens of full oscillations per turn of the front wheel. How could that be caused by brake disc runout?

I am still pretty sure that the root cause is resonance. It appears exactly like that, not at all like rotor runout. IMHO, still. [/emoticons/emotion-2.gif]