Anodizing gone from braking surfaces

In article said:

Have a Sun ME14A rim with about 3000 miles on it, and over the past few hundred (lots of gritty wet
riding) the anodozing started to disappear and is now almost completely gone from the braking
surfaces - anything to worry about or is this normal mode of operation?

Both - it is normal, and eventually you can wear it out. But that usually happens a long while after
the anodizing is removed. You deal with this via regular inspection for cracks around the nipples
and on the braking surfaces. The rim will crack when the walls get thin enough. Often you will find
failure around a spoke hole before you get enough miles on it to wear through the braking surface.

Paul Southworth said:

Quoted message said:

Have a Sun ME14A rim with about 3000 miles on it, and over the past few hundred (lots of gritty
wet riding) the anodizing started to disappear and is now almost completely gone from the braking
surfaces - anything to worry about or is this normal mode of operation?

Quoted message said:

Both - it is normal, and eventually you can wear it out. But that usually happens a long while
after the anodizing is removed. You deal with this via regular inspection for cracks around the
nipples and on the braking surfaces. The rim will crack when the walls get thin enough. Often you
will find failure around a spoke hole before you get enough miles on it to wear through the
braking surface.

Not such a good idea. I have on occasions worn rims to dangerously thin dimensions with no cracking.
Besides, cracks around nipples has nothing to do with brake surface wear. Find out ho wide the rim
was when new by measuring one in the store with calipers and then check you rim once in a while. Rim
walls are a bit over 1.5mm thick. When they get to 0.5 at the thinnest place it is high time to get
a new rim.

Jobst Brandt [email hidden] Palo Alto CA

Yes, it's normal. Your brakes (ALL brakes) work by friction. Friction + wear. Gritty riding, as is
encountered in MTB'ing, accelerates the process, of course.

Anodizing is only a controlled oxidation of the surface of the aluminum, which, unlike steel,
becomes harder when it combines with oxygen, protecting the metal underneath. The greyish coating so
familiar to old aluminum screen doors is, in fact, a natural anodizing.

However, this protective coating is only a couple of thousandths of an inch thick (a little thicker
than the hair on your head) when they were new, so it's not going to last forever. It's just a lot
more noticeable with "colored" anodizing, which I assume you have.

Don't worry about it, it won't harm your rims, they're just as strong as when you bought them.
Again, assuming you have cared for them properly.

May you have the wind at your back. And a really low gear for the hills! Chris

Chris'Z Corner "The Website for the Common Bicyclist": geocities.comczcornerOpen ↗

KBH said:

Have a Sun ME14A rim with about 3000 miles on it, and over the past few hundred (lots of gritty wet
riding) the anodozing started to disappear and is now almost completely gone from the braking
surfaces - anything to worry about or is this normal mode of operation?

I can remember being anxious for the anodizing to wear off my rims so they'd START braking well. The
worst part was when the anodizing wore off the braking surface at each spoke location first,
resulting in brake shudder (and a really non-Fabrizio-approved look).

Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home of the $695 ti frame

<[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

Not such a good idea. I have on occasions worn rims to

dangerously

Quoted message said:

thin dimensions with no cracking. Besides, cracks around

nipples has

Quoted message said:

nothing to do with brake surface wear. Find out ho wide

the rim was

Quoted message said:

when new by measuring one in the store with calipers and

then check

Quoted message said:

you rim once in a while. Rim walls are a bit over 1.5mm

thick. When

Quoted message said:

they get to 0.5 at the thinnest place it is high time to

get a new

Quoted message said:

rim.

Some newer rims have little wear dimples so you can tell when they've worn too far. I think these
are required by law now in Europe. Not a bad idea.

Matt O.

Anodised rims use harder brake pads--careful with these pads now the anodising has worn off they
scrub the walls alot harder. With thin walls make sure you dont jump.-I know its a road bike, but I
use mine in a similar fashion to cyclocross-failure on landing is quite spectacular.

"Mark Hickey" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

KBH said:

Have a Sun ME14A rim with about 3000 miles on it, and over the past few hundred (lots of gritty
wet riding) the anodozing started to disappear

and

Quoted message said:

Quoted message said:

is now almost completely gone from the braking surfaces - anything to

worry

Quoted message said:

Quoted message said:

about or is this normal mode of operation?

I can remember being anxious for the anodizing to wear off my rims so they'd START braking well.
The worst part was when the anodizing wore off the braking surface at each spoke location first,
resulting in brake shudder (and a really non-Fabrizio-approved look).

Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home of the $695 ti frame

Matt O'Toole said:

Some newer rims have little wear dimples so you can tell when they've worn too far. I think these
are required by law now in Europe. Not a bad idea.

Certainly not all across Europe.
--
David Damerell <[email hidden]> Distortion Field!

"Openworld" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

Anodised rims use harder brake pads--careful with these pads now the anodising has worn off they
scrub the walls alot harder.

I think you're describing ceramic-coated (sidewall) rims.

(Chris Zacho 'The Wheelman') said:

Good idea, Jobst. Now you have to get him a bladed micrometer to measure
it. And, of course, instruct him on how to read it, if he doesn't already know ;-3)

A regular old caliper works fine. You put a ¼" ball bearing in and measure with the caliper and then
make the adjustment. I bought a plastic caliper at a 99¢ store for 2/$.99.

Peter Cole said:

"Openworld" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

Anodised rims use harder brake pads--careful with these pads now the anodising has worn off they
scrub the walls alot harder.

I think you're describing ceramic-coated (sidewall) rims.

That was my guess as well. I've certainly never heard about using different brake pads for
anodized rims.

Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home of the $695 ti frame