Dreww10

I purchased a set of Dura Ace 9000 C35 clinchers a few months ago, replacing a set of stock Mavic Aksiums. Right away, there was a slight feeling of a "shudder" in the brakes, although nothing too serious, just not buttery smooth like the Mavics were. When just lightly pulling the brakes to slow, you could hear that the brakes were inconsistent in their contact with the brake surface. If I pull on them hard, the shudder goes away, but only then.

They gradually began to develop a very dark and pronounced dark wear mark all the way around the surface, which is somewhat inconsistent in its pattern, as well. I eventually had the wheels checked and the front didn't need any truing, while the rear just needed a very minor adjustment. Doing so however didn't change the wear or cure the shudder at all.

What's happened though, when looking at the wheel up close, is what I can only describe as the appearance of someone just taking random swipes at the brake track with sandpaper. There are scratches that aren't even in a steady pattern, but angled marks, swirls, and "stutter marks", in addition to the very awful-looking dark ring that's been worn into the surface. As well, the ring seems to be only at the top of the pad contact point, but not the bottom half, even though they appear to contact the wheel flush to the eye.

The pads have always been clean of debris, and at this point, I'm just at a loss for how to cure both the shudder and the damage that's being done to the wheel. Is there any way to polish that rough, dark wear ring out once I find a solution? When I look at the Mavics (which have a few thousand miles on them) they have just a perfect, clean wear pattern all the way around that look nice and clean even up close, while the C35's look like they've been ridden for 25 years with brake pads that are even older. It's kind of defeating mentally to spend so much on a set of wheels and have them looking awful within three months.

hueyhoolihan

brake pads and rims wear together, somewhat. did you put new pads on your brakes when you installed your new wheels? not that i have ever found it necessary, although i have to admit i rarely take notice of my rims.

a pic might help.

Carbonfiberboy 

Replace the pads immediately and wipe the rim down with alcohol. If that doesn't fix it, it's something else . . .

Dreww10

All of the small, random scratches are hard to photograph, but you can see the ugly black rings and their inconsistency in these shots. As a side note, I have sanded the pad surfaces down with fine-grit sandpaper, but haven't had a chance to ride them yet since doing so. Might this be adequate, or is it still suggested to replace the pads?

Carbonfiberboy 

Also when you changed wheels you probably reset the pads. You might have changed the toe-in, which might cause a judder.

Dreww10

I actually left the brakes completely as they were with the new wheels. Only when I had to install new cables recently I adjusted the top screw (Ultegra 6700 brakes) to see what effect that had, and the only result seemed to be increasing black wear on the wheel, but no change in the brake feel. I have now adjusted that screw all the way back in and re-adjusted the brakes with the cable anchor position.

MagicHour

Inspect pads visually to make sure there arent any embedded metal shards; sanding may not remove these but they can be dug out with Something sharp like an awl etc. Try replacing pads to something softer like kool stop, Swiss stop etc. I was using the stock shimano 6800 pads this season and found brake performance improved greatly after switching to KoolStop dura 2 dual compound pads.

Dreww10

I'll have to give that a try. Does a darkened surface like this eventually work itself out, or is more or less permanent? It honestly looks like a black anodized wheel thats just been worn down, rather than polished as it should.

MagicHour

Could just be residue from pads. I have ROLs and they recommend this, which I did after ~2,000 mi
https://www.rolwheels.com/service/how...of-your-wheels

Ymmv, so check out documentation of your wheels and see what they recommend if anything.

hueyhoolihan

looks like normal black rubber pad residue. i've removed it on occasion with a scrubbie type pan cleaner. IME, that stuff may or may not come back, depending on the brake pads used. i've gotten to the point that it's expected.

Dreww10

I just tried some rubbing alcohol and the darker area is definitely not brake residue. It appears to just be much deeper wear than the rest of the surface. Seems hard to believe that deep of wear could be possible however, considering they have just 1,500 miles or so on them in a pretty flat area.

Bob Dopolina 

This,

Go over the rim completely. Use a few drops of water in the process, then clean the rims.

For the brake pads hand sanding gives them an uneven surface. Instead use a LARGE flat file and drag it across the surface of the brake pads. This should pull out any debris and brake down the burnished surface of the pads (which will also improve braking).

BoJaffa

I would try cleaning everything up abit while waiting for new pads. Wheels are expensive, pads are cheap in comparison.

rm -rf

EDIT--~~~~~my original post:
KoolStop Salmon pads work great and don't leave a black residue. They seem to be less likely to pull small bits of aluminum off of the rims, too.

The brake track on many new wheels is rougher than it will be after the brake pads smooth it off. That takes at least a few hundred miles for me.

That link mentions 220 sandpaper. Be extremely careful with any sandpaper on rims. Years ago, I tried sanding out an uneven join edge with 400 grit wet-and-dry sandpaper. It's very easy to sand down aluminum too much, and I ended up with a slight depression there.

I'd switch to KoolStop pads, and see if the markings go away after a hundred miles or so.

To clean rims, try a rag and rubbing alcohol. Then, if it's still bad, use a fine scrubber and alcohol or water. I have the bike on a stand (or maybe flipped over) and fold the scrubber so it only touches the brake track, and hold it steady near the brakes while I turn the wheel. Just a light touch! For extreme cases, 320 or 400 sandpaper, wet-or-dry can be folded to the width of the track and used like the scrubber. Wet the sandpaper with water first so it won't clog up immediately.

Don't try to get the rims perfectly smooth and clean, just get the worst off.

Resurfacing pads
My flat file worked somewhat. But the best way for me is some 180-220 grit sandpaper, held down on a flat surface with one hand, and dragging the brake holder+pad across it. It was way faster than my file.

Carbonfiberboy 

Another possibility is that there's something up with your roads. You have more black stuff nearest the road, less on the track more away from the road. You might be picking up something off the road that's sticking to your pads or bonding to them or something. Do you hear a grinding, SSSS noise when you brake or are your brakes silent? A change in pad type as others recommend might fix this.

woodcraft

I think that you mis-overestimate your sanding effects there.

DXchulo

Looks normal to me. You can clean the heck out of them with a scrub pad as mentioned above, but they won't stay shiny and new looking for long. I'm sure on a microscopic level that junk is eroding your rims over time, but from a practical standpoint it's nothing to worry about. Just make sure you don't have chunks of metal stuck in your brake pads.

My rims look a lot worse than that.

Dreww10

Will a Scotch Brite pad scratch the alloy surface? They're not sandpaper, but they're pretty darned rough.

Bob Dopolina 

No. Add some water and they do a great job. Your rims will thank you.

woodcraft

No death or dismemberment will happen if you scratch the alloy surface. I am living testimony.

#220 w/d or scotchbrite. sand the brake blocks too, w/ sandpaper on a flat surface.

Clean w/ rubbing alcohol.

gsa103

Uniform black is normal brake residue for Shimano pads, and unrelated to the shudder. I had the same problem with my C24s initially. If the wheel is a different width at the brake track, you'll need to reset the pad angle.

Loosen the pad slightly clamp the brakes down, then tighten. The do a few hard stops, after which it should work well. Except for the black stuff, that's just life.

Dreww10

Well this story has gone from bad to worse. I finally went and purchased some Kool Stop pads, installed them and took the bike out for a short ride today. Both front and rear the braking sound was horrendous, like metal being sheared off. Lo and behold, the front pad ripped a chunk right out of the brake track and then continued to just eat the wheel away, even in areas outside where the metal piece was. The pads left a very pronounced groove all the way around the wheel, and you can both see and feel where it's pushed the metal up, leaving lumps al the way around the wheel. At this point, I have to assume the wheel is completely junk, short of it being machined down, because there's so much metal lumped up that it'll just continue to rip away and lodge into the brake pads. Never mind that the wheel now just look terrible, and is largely permanent.

Brian Ratliff

This just doesn't happen with brake pads unless they are installed incorrectly. How about a picture of your brakes and brake pads?

02Giant 

Any chance the braking surface has clear coat on it?

Dreww10

Here's the photo of the pads. The bike is upside down, as you can see, but the pads are installed correctly, as were the Shimano's that were also grinding them up pretty good.