Front Brake Pad Wear

[Rolavine]

I replaced the front brake disk pads yesterday at 29,000 miles. They still had life left but I had noticed that there was a scraping noise comming from the front brakes when I moved the bike around by push power. I had experienced this before on other bike and generally just changed the pads to get rid of it. when I pulled the pads from the FJR I noticed that there was a section of the pad on the side with the pin that had not been worn at all, as it never touched the rotor. There was a good 16th of an inch of height difference between the warn parts and the rear part. I put the new pads on and the noise that went with manual movement of the bike was gone. But now I wonder if it was just caused but the unworn part of the pad touching the outside edges of the rotors? The normal opening of the pads when the brakes are off would still keep this unworn part in potential contact?

Anyone know if this is it?

Thanks, and if this has been covered here before I couldn't find it even with a google search.

 

[Geezer]

I have not noticed this on my FJR. Did you have Yamaha pads on there or aftermarket?

 

[Fred W]

I think that I know what you are talking about, but a diagram or other elucidation may be helpful.

If what you are talking about is that the pad extends radially beyond the disc, and the unworn part of the pad is rubbing on the outer circumference of the disk, I have not noticed this, but I could see how this could happen. The brake disk (aka rotor) is machined and true only on its flat faces. The circumferential edge, while machined, is not necessarily perfect and so you might have an intermittent grinding noise when pushing the bike along.

So long as there is enough meat on the pads, and there is no pulsation of the brake power felt during use, I'd have just kept going with the old pads.

 

[FJRBluesman]

Pix would help here. I'm assuming you're talking the same pad and a little spot that doesn't contact the rotor maybe at the top Vs a section either front or rear that is angled like the pad has worn as a wedge.

I think Fred has it, if that's what you meant, if so yes, I've seen this many times on bikes and cars; however, my FeeJ does not do this.

 

[Rolavine]

Pix would help here. I'm assuming you're talking the same pad and a little spot that doesn't contact the rotor maybe at the top Vs a section either front or rear that is angled like the pad has worn as a wedge.
I think Fred has it, if that's what you meant, if so yes, I've seen this many times on bikes and cars; however, my FeeJ does not do this.

Yes, the condition is just as you describe it, interesting that this does not happen on your bike, maybe it is only an 03 thing?

I don't know if the pads were original I bought the bike used at 18,500, they didn't say Yamaha on them.

The slight noise of the pads lightly touching the rotors is back after the first ride, it is less than with the old pads, again I think because of the unworn sections.

The new pads worked very much better though with much smoother stops, they require a bit more pull and I suspect that is because they have not seated to the rotors yet. I was getting pulsation on the old ones when braking very hard. I only did this when practicing panic stops, as I've been lucky to only have to do this for practice.

I'll take a pic of the old pads and post it here.

 

[C&C]

Maybe that's the answer (an '03). If an '04' or greater set of pads fits (assumption here) on the '03' caliper, you may be seeing the difference in diameter of the rotors, imprinting on the pads.

 

[Fred W]

The pads on my '05 do not extend to the edge of the brake rotor, so there is not chance for the lip you mention to form.

I wonder how tough it would be to fit a set of '04/'05 non-ABS brakes on there, or if the fork legs would have to be changed as well. You'd get a bigger, more powerful brake disk and no more of this issue. Then again, the brakes probably work OK, just make an aggravating noise.

 

[Rolavine]

The pads on my '05 do not extend to the edge of the brake rotor, so there is not chance for the lip you mention to form.I wonder how tough it would be to fit a set of '04/'05 non-ABS brakes on there, or if the fork legs would have to be changed as well. You'd get a bigger, more powerful brake disk and no more of this issue. Then again, the brakes probably work OK, just make an aggravating noise.

I tried to post the pic on the Picassa service run by google but the forum won't take it?

I don't have time to try posting it again somewhere.

So just picture a front brake pad with about a centimeter of unused frictional material running in an arc on the outside, and the rest of the material worn away by contact with the rotor.

There is the pic of one of the front brake pads.

I suspect what I have here is:

The bike has a reconstructed title.

The bike had a bent front axle when I got it, the front tire was toast and it handled very bad.

I suspect that the 'cosmetic damage' included the destruction of the original front forks.

I supect that the front forks were replaced with gen 1's from a 2004 or newer bike, so the calipers are mounted in a position for the larger rotors.

I suspect I have the orginal smaller rotors from the 2003 on the bike.

Evidence, that upper unused arc is just about a centimeter thick.

I'll try to check this out over the weekend but it seems reasonable.

This isn't bad because I was delighted with every aspect of the FJR but brakeing!

The weird thing is the brakes worked well under nornal conditions and only shuddered under severe test brakeing.

If this is the problem maybe I can just get by with a set of the larger rotors from a gen 1?

Any one know if the larger gen 1 rotors will bolt on all gen 1 wheels?

Thanks for your help, this dangerous condition could have gone undiscovered for longer. I bought the bike last September and have put over 10K on it since then.

 

[bikerkash]

I just had a 20K service on my 08 and the tech said the pads still look like new.

 

[Constant Mesh]

The '03 front disc has a 298 mm diameter and is 5 mm thick. The '04 disc has a 320 mm diameter and is 4.5 mm thick.

Radius difference = 22 / 2 = 11 mm = 0.43 inches

On my '04 the outer 2 mm of the disc radius is virgin metal -- untouched by the brake pads.

Mating '04 forks with '03 discs would leave a 9 mm wide unused portion on the pads.

 

[Rolavine]

The '03 front disc has a 298 mm diameter and is 5 mm thick. The '04 disc has a 320 mm diameter and is 4.5 mm thick.
Radius difference = 22 / 2 = 11 mm = 0.43 inches

On my '04 the outer 2 mm of the disc radius is virgin metal -- untouched by the brake pads.

Mating '04 forks with '03 discs would leave a 9 mm wide unused portion on the pads.

Yes, my virginal gap (yikes!) is about a centimeter, actually I can get 9mm depending on how I set the calipers into the gap. I arrange to buy FJRBLUESMANS recently removed and famously well documented FRJ Forum rotors to try a rotor transplant. I suspect this will reveal the truth. The parts fiche shows a seperate right and left rotor, does anyone know why that is and how I can tell one from the other? I think I should be able to figure this out.

Looking forward to eliminating the one area where I thought my FJR was deficient, the brakes of course!

 

[Constant Mesh]

Left and right discs are identical -- have the same part# 5VS-2581T-00-00 for '04 and '05 models.

 

[RadioHowie]

The parts fiche shows a seperate right and left rotor, does anyone know why that is and how I can tell one from the other?

Easy-peasy.....the right rotor turns clockwise.

 

[Rolavine]

Left and right discs are identical -- have the same part# 5VS-2581T-00-00 for '04 and '05 models.

Right, sorry, I don't know where I got the idea they were different, humm.

The good news all my rotor bolts came off just fine with a regular bent hex wrench.

I tested this just to make sure I didn't need new bolts.

 

[Rolavine]

Problem solved, I had 2003 wheels and rotors on forks that must have come from 2004 or newer bike, so this put the brake calipers about a centimeter too high creating the band of unsed brake pad material. I put on a used set of rotors from a 2004 and they fit fine. The shuddering on quick stops is gone. This was really a dangerous condition and the Yamaha shop that repaired the bike should have known better. But even impaired as they were these brakes worked better than most of the brakes I've had on bikes since way back when. Pretty damn amazing they worked this well, and I can understand why no one noticed this until now (11,000 miles since).

Without the feedback from this topic I'm not sure I would have been able to realize there was a problem and then to fix it, thanks much.

 

[FatNakedGuy]

These are the original pads on my 04 bike at 31000.

Left side

Right side

 

[Constant Mesh]

You can easily swap the front pads and extend their life. On my '04 the inside pads wear faster than the outside. So I exchanged them.

Moved left inside to right outside, left outside to right inside, etc.

 

[Fred W]

Problem solved, I had 2003 wheels and rotors on forks that must have come from 2004 or newer bike, so this put the brake calipers about a centimeter too high creating the band of unsed brake pad material. I put on a used set of rotors from a 2004 and they fit fine. The shuddering on quick stops is gone. This was really a dangerous condition and the Yamaha shop that repaired the bike should have known better. But even impaired as they were these brakes worked better than most of the brakes I've had on bikes since way back when. Pretty damn amazing they worked this well, and I can understand why no one noticed this until now (11,000 miles since).

That is awesome news. You now may have the best stopping '03 around!! :yahoo:

You can easily swap the front pads and extend their life. On my '04 the inside pads wear faster than the outside. So I exchanged them.
Moved left inside to right outside, left outside to right inside, etc.

Yup, same wear pattern here on '05 after 26k miles.

I was alarmed when I first noticed it, but it seems many (all?) of the 1st gens brakes wear this way.

I need to swap the pads around on my next tire change.