ceramic rims : risks?

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

Quoted message said:

Doing some background reading via google, there appears to be a slight concensus that ceramic rims
can be trouble.

My LBS had recommended (and I accepted) Mavic x618 rims coupled to 36 XT and Schmidt hubs. The
x618 comes sporting a sticker "inspect regularly". The newgroups mention the ceramic cracking.

What's the real story? Baring in mind I'm not wearing a cap back to front and bunny hopping off
garage roofs. They are 26' wheels fitted to my touring bike.

If there is a problem, can it be alleviated by using different brake pads? What is one supposed to
look for and where on the wheel?

You should use the pads specifically designed for these rims. It has been speculated that the
thermal insulating quality of the ceramic coating interferes with the heat transfer enough to cause
pad melting/glazing. I don't know if the ceramic-specific pads alleviate this problem completely. I
have one pair of these rims, which I have used with both styles of pad, without noting anything
terrible in the braking, but then not in severe braking situations either.

The other concern is that the ceramic may chip off in spots, causing uneven braking. I think the
real danger of this happening is off-road riding, where it's not unknown to ding the rims from
glancing blows on rocks. I've managed to ride mine off-road for many miles (~1000) in rocky terrain
without doing this.

My ceramic rim became "polished" over time. It was a bit grabby at very low speeds. However, the
real problem was it had zero braking performance when very wet. I would say it was dangerous.

They worked pretty well until that point. So if you get them, expect to need to rebuild your wheels
at some point.

-Dion

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

Quoted message said:

Doing some background reading via google, there appears to be a slight concensus that ceramic rims
can be trouble.

My LBS had recommended (and I accepted) Mavic x618 rims coupled to 36 XT and Schmidt hubs. The
x618 comes sporting a sticker "inspect regularly". The newgroups mention the ceramic cracking.

What's the real story? Baring in mind I'm not wearing a cap back to front and bunny hopping off
garage roofs. They are 26' wheels fitted to my touring bike.

If there is a problem, can it be alleviated by using different brake pads? What is one supposed to
look for and where on the wheel?

thanks,

--
Walter Mitty.

I rode 517 ceramic rims for a long time until i converted to disc brakes.... ceramic rims stand up
well in wet/muddy terrain .. and they do work when wet.. unlike non-ceramic rims. They are the next
best thing to disc brakes.

Yes.. they can get chipped... but unless the chip is extremely large, it should not cause a problem.

it is imperative that you use ceramic specific brake pads... regular pads will wear out almost
instantly.. especially in muddy conditions.

charlie

Member Help Community Leader

Hey Dion. Mavic recommends using a Ceramic Rim Eraser (basically a soft-stone, available where you
get your skates sharpened or your skis/snowboard tuned..... and for less than Mavic charges) to
clean the glaze from the ceramic. The Glaze was the cause for the slipperyness when wet you endured.

"The knack lies in learning to throw yourself
- at the ground and miss" Douglas Adams.

Take care. Keith Pears.

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

Quoted message said:

My ceramic rim became "polished" over time. It was a bit grabby at very

low

Quoted message said:

speeds. However, the real problem was it had zero braking performance

when

Quoted message said:

very wet. I would say it was dangerous.

They worked pretty well until that point. So if you get them, expect to need to rebuild your
wheels at some point.

-Dion

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

Quoted message said:

Doing some background reading via google, there appears to be a slight concensus that ceramic
rims can be trouble.

My LBS had recommended (and I accepted) Mavic x618 rims coupled to 36 XT and Schmidt hubs. The
x618 comes sporting a sticker "inspect regularly". The newgroups mention the ceramic cracking.

What's the real story? Baring in mind I'm not wearing a cap back to

front

Quoted message said:

Quoted message said:

and bunny hopping off garage roofs. They are 26' wheels fitted to my touring bike.

If there is a problem, can it be alleviated by using different brake

pads?

Quoted message said:

Quoted message said:

What is one supposed to look for and where on the wheel?

thanks,

--
Walter Mitty.

I am puzzled by your comments:

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

Quoted message said:

I rode 517 ceramic rims for a long time until i converted to disc brakes....

What has changing to disk brakes got to do with the rims? Why did you change rims when fitting
disk brakes?

Quoted message said:

ceramic rims stand up well in wet/muddy terrain .. and they do work when wet.. unlike
non-ceramic rims.

In what way do ceramic rims "stand up well" in wet/muddy conditions? My (non-ceramic) 517 and 618
rims "work when wet" too - what is the diference?

Quoted message said:

They are the next best thing to disc brakes.

Why are ceramic rims better? What decisive advantages outweigh the disadvantages of poorer braking
and dangers of cracking commonly reffered to in this and other threads.

Not trying to make a point, just genuinely puzzled by your comments.

Andrew Webster

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

Quoted message said:

I am puzzled by your comments:

Why are ceramic rims better? What decisive advantages outweigh the disadvantages of poorer braking
and dangers of cracking commonly reffered to in this and other threads.

The entire reason for ceramic rims is to lengthen the lifetime of rims, particularly in wet trail
use. Rim lifetime is determined by sidewall wear rate. In wet conditions, rims pick up abrasive grit
and wear out quickly, muddy trails can go through rims quite fast, depending on the local soil.