V-Brake pads for Ceramic Rims?

[Justin]

Hi all

 

I bought mavic ceramic rims, but my v-brake pads don't want to stop me. I'm scared of ending up like Evans!

 

What pads should I get?

 

So far I heard that there are avid rim wranglers (green compound) for ceramics, but CRC don't have.

 

Anything else?

 

Cheers

[weeFrisbee]

I bought my ceramic v-brake pads from CWC...works like a bomb.

[Justin]

I bought my ceramic v-brake pads from CWC...works like a bomb.

 

Thanks, will check them out!

 

My normal rim wranglers really just bring me to a gradual halt. Sometimes that's not enough!

[Justin]

It seems CWC only have disc brake pads

[Johan Bornman]

Those ceramic rims are very problematic. Ceramic (glasslike coating) is a great insulator.

 

In a friction material, most of the heat is generated in the softer of the two compounds and then transferred via conducation, convection or radiation, to the surrounding parts. In most brakes, the softest part is the pad - be it a rubber pad or a disc pad.

 

The heat in the pad gets transferred to the disc or rim via conduction. The rim then dissipates the heat and the pad stays below melting point.

 

On ceramic rim, the heat cannot be transferred thanks to the layer of insulation between the pad and rim. The pad therefore reaches melting point and behaves like you describe. It brakes very poorly.

 

The only way to overcome this problem is to fit a pad with a very high melting point. Something even that doesn't melt but just sublimates. Cork is a good example of the latter - it goes from hot to smoke withoug the liquid stage.

 

Ceramic rims are actually just an halfbaked solution looking for a problem. Non-coated rims are better and work with all pads.

[Justin]

Those ceramic rims are very problematic. Ceramic (glasslike coating) is a great insulator.

 

In a friction material, most of the heat is generated in the softer of the two compounds and then transferred via conducation, convection or radiation, to the surrounding parts. In most brakes, the softest part is the pad - be it a rubber pad or a disc pad.

 

The heat in the pad gets transferred to the disc or rim via conduction. The rim then dissipates the heat and the pad stays below melting point.

 

On ceramic rim, the heat cannot be transferred thanks to the layer of insulation between the pad and rim. The pad therefore reaches melting point and behaves like you describe. It brakes very poorly.

 

The only way to overcome this problem is to fit a pad with a very high melting point. Something even that doesn't melt but just sublimates. Cork is a good example of the latter - it goes from hot to smoke withoug the liquid stage.

 

Ceramic rims are actually just an halfbaked solution looking for a problem. Non-coated rims are better and work with all pads.

 

Bummer. Thanks for the detailed info. Now I see the logic behind the failure.

 

I suppose I can put my old rims back on, but the mavic's look so cool...