Ceramic Rims and brake blocks

[stutho]

Reminded myself yesterday why I have got ceramic rims. I was descending the steep hill indicated (speed ~40mph) when at about the worst possible moment a man walked out from behind a hedge (without looking) dragging a large tarpaulin! There is no way my other bike would have stopped in time and there was no room to swerve - due to the tarpaulin. AS it was I braked EXTREAMLY hard front and rear (locking up and releasing the rear twice). Finally I came to a stop about 3 foot short! The guy only saw me after I stopped - I should of shouted a warning but I was to busy controlling the bike at the time.

For the record my bike is set up with Mavic 717 ceramics, Coolstop salmon front (with a booster) and Coolstop green rear. Both callipers are Avid Ultimates being puled by dia-compe 287V drop levers. Neither brake makes any noise and brake pad ware is the now the same as with non-ceramic rims.

[lewisnoble]

Phew!!  Are you sure you don't have ABS as well??

[stutho]

No but I do have brown pants!

[ahconway]

So I was changing to my summer tyres today, and I was horrified to see the condition of my rear ceramic rim.

The sides are spotty, and it looks like the finish has "flaked off" as others in this threat have mentioned.

No problem on the front rim, though. I've been using Shimano pads for ceramic rims on both.

What's going on here? Is this something I need to be concerned about?

[mountaincarrot]

I think they just wear out!

I commute (XC riding only)in sandy Surrey hills and got through a pair of standard Mavic XC rims in about 2000 miles. I then changed to some heavy duty DH Ceramic Mavic rims (Can't remember the number). The ceramic on the rear had it's first holes in after 2000 miles, and now has largely disappeared on the rear rim, and I'm down to wearing out the aluminium. The front is still 50% ceramic coated. This is after ~5000 miles with just a few very short dabs of the brakes each day.

The Shimano ceramic pads did the initial damage (pockmarks after 2000 miles). Since themn I've run ordinary Koolstops on them. I can't say the wear on the rims is any worse, but they don't stop as well as the new set-up with ceramic pads.

I recon I'll get 5000 miles from the ceramic rims versus 2000 from ordinary. (That's with XT parallel-action brakes).

[stutho]

Hi Ahconway,

Sorry to here you are having problems with you rims.  The problem of the ceramic coating wearing off (especially on Mavics) has being reported by a number of people on the net.  People using Shimano pads seam to be particularly vulnerable - I would switch the pads out straight away if I were you.  

As a data point I have currently got about 7000 miles on my ceramic rims the front rim looks almost new and the rear looks older but has no sign of ceramic ware (I use Koolstop salmon pads).  

[ahconway]

Geez!

Thanks Stutho. Exactly which pads do you use? There are lots of salmons by Kool Stop!

[stutho]

I have used salmon Thinlines but currently I use Salmon V-Brake inserts.  You probably know this already but the Salmon colour is an all weather compound. I have also used the Green, ceramic compound, which I did not find as good as the salmon.

thinline (not salmon)

V-Brake inserts (not salmon)

[img=left]http://www.koolstop.com/brakes/thinline.jpg[/img=left][img=right]http://www.koolstop.com/brakes/V-Dual2.jpg[/img=right]









Clearly I have V brakes!!

[Magnus Thor]

Strange!  I've been using ceramic rims for the last 4 years, Mavic 721 XC.  I think I have clocked up around 15000km by now and a lot of that is winter riding, with all the sand, salt and grit that entails.  I started using standard brake blocks, but switched over to ceramic specific after approx. 2000km.
So far the rims look pristine...


Magnus Thor
Iceland

[Magnus Thor]

Strange!  I've been using ceramic rims for the last 4 years, Mavic 721 XC.  I think I have clocked up around 15000km by now and a lot of that is winter riding, with all the sand, salt and grit that entails.  I started using standard brake blocks, but switched over to ceramic specific after approx. 2000km.
So far the rims look pristine...


Magnus Thor
Iceland

[avdave]

I've just ordered avid ceramic pads for my Catalyst, I'll let you know how i get on with them. The original pads have lasted over a year but there are'nt many hills on my commute. I've also worn the rear down faster than the front but I think thats because I tend to use it as a drag to regulate speed while changing gear with my right hand and using the front brake when I acctually need to stop. I have thought about reversing the brake levers so that I'm not controlling what should be the primary brake and the gear change with one hand. Has anyone done this?

[pdamm]

I have the shifter on the left had side so my right can use the front brake.  Swaping the braks around would also achieve one hand for the important front brake and the other for the shifter.  I didn't do it that way in case I rode somebody else's bike and got confused when I really needed the brakes.

[avdave]

Thats a good point pdamm, worth considering as an option.

[stutho]

On my RST (with drops) the shifter is on the left for the exact same reason.  On the wife’s RT (flat bar) the shifter is on the right as you don’t need to move your hand from the bar/brake to shift there seems little point in mounting this one on the left.

[RJC]

If using Rigida CSS rims another option is Koolstop CSS ceramic compound.
I guess this is different to their standard green ceramic compound. When Rigida
developed the CSS coating Koolstop developed a brake compound in collaboration
with Rigida. I don't know why Koolstop don't mention it on their website.

Available in cantilever, V-brake & road brake style blocks.
In the UK you will probably need to contact the importer (Amba-Marketing)
who should be able to point you to a shop that can order the pads.
I believe the price should be similar to Koolstop dual compound.

[Edit] SJS now have these KoolStop CSS blocks in V-brake and post mount style.
The latter could be useful for cantilevers since SwissStop blue is only available
in v-brake style.

Picture below - you might need to be logged in to see.