twocicle

We used the 6-bolt XT RT86 ICE rotor last year with great success.

Here is a performance comparison article covering the ICE rotors last year. The writeup in that link shows just how effective the rotor can be under what they call "normal usage". The numbers may not cover heavy tandem usage, but it is a quantitative comparison nonetheless.

The latest and greatest ICE rotor out on the market is the Saint RT99 which incorporates heat sink/vents. Unfortunately it is available only with centerlock (not 6-bolt) and there is no way (AFAIK) to mount a centerlock rotor to a 6-bolt hub.

For this new version, Shimano claims:

• Additional 50°C decrease in operating temperatures over previous Ice Technology rotor
• Braking and performance benefits include 20% less brake fade, 20% increase in stopping power and 20% longer pad life
• Available for center lock hubs
• 3-layer clad rotor – steel / aluminum / steel
• Weight is 173g, which is 21g lighter than the last 203mm rotor.

With a quick search on pricing, I found ranges from $129 for available now (Jenson), to $81 in May (Chainreaction).

Note again, there is no way (AFAIK) to mount a centerlock rotor to a 6-bolt hub.

gracehowler

Anyone wonder if the vents will suck up power?
R&J

Dean V

These do perform well on the tests but they were all done at quite low power levels (1050W max). At these numbers the disc has the opportunity to dissipate the heat through their cleverly designed construction/materials. With hard stopping from high speeds the power levels are considerably more than this.
To bring a 140kg team from 50mph to stop in 10s requires an average braking power of around 3500W. This doesn't account for aerodynamic drag which would reduce this number, but if you were still going down the hill and not on the flat it would increase it.
Then the heat dissipation aspect will be overwhelmed and survival of the system would be more dependent on its thermal mass and how much heat it can stand.
You and others have been happy with the ICE rotors so they must be ok, just saying that those test numbers don't really paint the whole picture. The weight and speed requirements of a tandem move it outside of what they tested for.

Ritterview

I saw this disc on a NAHBS pic.



My interest piqued, I looked it up. It appeared on several NAHBS bikes, including this discussed at Bike Rumor.

I checked out a thread at Weight Weenies. Kettle Cycles Carbon Rotors. Users found that it was light, and the early reports were good.


160 mm (the equivalent one piece rotor was 116 grams).

And an article from Bike Radar. Can carbon rotors provide better braking?

I thought this video showed that there was sufficient toughness to the rotor.


So, I called Josh at Kettle Cycles, and talked to him about using it on a tandem. He thought that the heat shedding properties of the rotor would be better than a steel rotor, and that the strength of the rotor was sufficient for a 295 lb team.

So, I ordered a 203mm rotor SiCCC SFL, which I hope to receive around March 20th. Its weight is listed as 94 grams, which about half the weight of an Avid 203 mm rotor.

Chris_W

Just to clarify, I've only used the XT rotor with an Avid BB7 as the front brake on my SINGLE cyclocross bike with a 160mm rotor, never on the tandem. I have been very happy with it in that setup, though.

My current favorite rotor for the tandem is a Formula 220mm rotor that we have on the rear. It gives way smoother braking than the stock Avid 203mm rotor, plenty of power, and also seems to have less problems with warping than the Avid.

PMK

Carbon brakes are way cool, but typically require heat to be efficient.

Most composites do not do well in heat transfer. I would expect a lot more heat going into the brake linings, caliper and heatsink (frame). No proof that these are that way, just the typical things seen before.

While at SAMPE a couple of years ago, I spoke with one of the venders that solely produced carbon brake rotors. We discussed the bicycle application, maybe this is in conjunction with them. I was very impressed by all they were doing. I'll see if I can find the trade show info to post here.

PK

rdtompki

We have the ICE XT on our tandem (rear). I can't say one way or the other as to its superior heat dissipation during long, steep downhills, but in ordinary hard braking the "feel" is much more progressive than the stock steel Avid. It may also be that the construction is less prone to warping. Certainly our rear rotor has remained true. I have some of the Avid HSX rotors that I'm going to try on my Volagi. I'll report back on how these compare to the stock Avids.

merlinextraligh

10 seconds for 50mph to 0 seems like an awfully long time. I know my car can do 60-0 in under 100 feet, which would be only a couple of seconds.

Never timed how fast a bike stops, but just by experience, we can slow down about as fast as a car. Hence, I'm thinking full on panic stop would be even higher watts.

twocicle

Sorry about that Chris, I was under the impression you also used the ICE on your tandem. I updated the OP accordingly.


Fixed the link to the comparison article in the OP.

I believe the test was limited to a maximum of 1050 watts, it did not venture higher and did not indicate anything about results at a higher (ie: beyond what they call "normal") usage.

The fins on the RT99 are designed to stir air to aid in cooling, so it will have some potential for increased drag. Since most tandems use discs on the rear wheel only, this would be of little concern to most teams (racers concerned with aero may think otherwise).

FWIW, in real world use I did some brief testing of my own, slamming the RT86 rotor through downhill stop tests and did not notice it fading. The bite on the disc is very good. Those sanity checks did not include >8% grades, or use like a drag-brake as some people tend to do. My thinking is that this new RT99 rotor will perform all that much better, especialy for teams who make heavy use of their brakes.

Ritterview

I agree with everything Chris_W says about the Formula 220 mm rotor in comparison to the Avid. It as greater heat capacity and shedding, it doesn't warp, and it stops with alacrity. Unfortunately these were discontinued in 2009. For our Calfee, we had to have the chainstay modified to accept it. The weight is 219 grams, in comparison to 190 for the Avid 203 mm. There is also some extra weight in the 220 mm brake mount. I'm hoping that the Kettle carbon-ceramic rotor will have better-than-Avid heat capacity, while saving >100 grams vs. the Formula.

Dean V

Looks good if you want to use your brake disc as a cut off wheel in the grinder, apart from that I guess you will find out.
Also bear in mind that the construction of carbon brake discs as used in motorsport is a completely different process (much slower and more expensive) to what you would normally associate with making things out of carbon fibre. These discs are definitely not using that technology.

Team Fab

From my memory cold CF rotors have much less power when cold. They will be no good for this application. However may be a great drag brake.

twocicle

I just reweighed a couple 203mm rotors laying around:

Avid steel one piece (from 2012 BB7 package) = 230gm
ICE RT86 steel/alu sandwich w/alu spider arms (incl mounting plates) = 176gm

ahultin

Can you even get an adapter to go from an ISO hub to a centerlock disc? I know you can go the other way but have never seen the adapter you would need

twocicle

No, and you actually quoted me saying just that twice

The entire exercise is a mute point hinging on if/when Shimano produces a 6-bolt version of the rotor, or if anyone has a centerlock hub on their tandem (not likely).

Dean V

As long as there is sufficient material thickness where the bolt pattern needs to be drilled no reason why you couldn't machine one to fit.

twocicle

For Shimano, it should be just a matter of mounting the disc part to a 6-bolt spider instead of the centerlock. For some reason they have not clued into that yet, or are deliberately pushing the centerlock by staying proprietary on this rotor.

As far as mounting a centerlock rotor to a 6-bolt hub... if they could have, somebody would have made an adapter by now, right?!

There are a bunch of people in a mid-west state just itching to say: Show me

Dean V

It can't be done with an adapter. The rotor needs to be machined. Sometimes you just can't use a bolt on fix!

ahultin

LOL , totally missed that line the two times i read it

twocicle

Ah, I get it now.

If one were to go that far, then I'd look first at the rivets joining the disc and spider as a possible swap point. If the disc holes line up on both models then perhaps it would be a relatively easy change over. Realistically though, it's best to wait and see if Shimano comes out with a 6-bolt version.

PMK

For this group of conservative take no risks personalities, removing the rivets and replacing the disc assemblies center hub appears frivolous and renegade.

PK

Ritterview

It looks like Kettle Cycles isn't the only to be with a composite(?)rotor. The Alien-Machinery Ceramic - Carbon fiber Brake disc.

At the Taipei Bicycle Show.

TandemGeek

Darn shame all disc rotors / hubs aren't CenterLock... That is one slick system. I have it on a set of my single MTB wheels and it's absolutely the nuts.

That said, for the 20-30 tandem teams around the world who are in "need" of better rear discs, they'll have to keep adapting what ever comes along for the MTB and Cross markets.

Again, bear in mind that the tandem manufacturers can't even entice crank builders to address the tandem market give the very small demand. As Brian Davis from da Vinci noted at this year's Tandems East Expo, FSA can pretty much satisfy the entire annual new production needs of American tandem builders in about an hour's production time. Hardly worth the set-up costs and certainly not a driving force behind getting them to entertain building cranks in a wide range of crank arm lengths or different bottom bracket interfaces as the cycling world continues to find something that doesn't have issues, i.e., Octalink I/II, ISIS I/II, MegaExo/Giga/Hollowtech, BB30, etc. I'm still surprised that Shimano even decided to get back into the tandem crank business, although they may have simply done a single production run that will last a decade... kinda like the last Trek T100/T200 frame run that provided several years worth of inventory back in the 90's.

twocicle

What kind of pads would you use with these ceramic/carbon rotors?

Regarding CenterLock vs 6-bolt, vs ..., the Chris King thread got me looking their tandem hub with the Universal Disc Adapter. That might be the way to go as it allows for virtually any rotor type. $400-500 just for the rear hub though. Any other hub mfr have a similar universal disc adapter?

Ritterview

At the Kettle site there is some pad info available.

Someone on the MtBR site preferred organics.

So, with these rotors, of course, I get organics with the aluminum backplates for lighter weight! The steel backplates weigh 24 grams.