Carbon Disc rotors

Questions about purchasing bicycles and parts

Re: Carbon Disc rotors

Postby jacks1071 » Wed Mar 13, 2013 1:44 pm

barefoot wrote:If you look at cars with carbon or ceramic brakes, they don't just take standard calipers and pads, and slot a same-sized carbon rotor in to the system in place of a cast iron one. The ceramic rotors I've seen are huge - at least an inch and a half thick, and with lots of material bulk (the cooling vents are quite small). The calipers obviously work the same way, but they have to be bigger to fit over the monster-thick rotors. Friction materials are quite different.

I'm still not keen on the idea of using a 2mm piece of carbon-reinforced plastic, with pads that are designed to be used on stainless, to stop my bike. But hey, I tend to be conservative about these thing.

tim


Check these ones out, the rotor dimensions look pretty similar to the steel equilivants.

http://www.hangar111.com/shop/589-true- ... front.html

They are a pretty new product, I guess the cost of manufacturing this stuff must be comming down?

I have seen some other ones, rotor only that they said you can use with any brake pads and your existing caliper. You could be into blank chinese frame territory though..
Our Website is: http://www.pro-liteoz.com Find us on Facebook by searching for "Pro-Lite Australia"
User avatar
jacks1071
 
Posts: 2944
Joined: Thu Aug 20, 2009 9:47 pm
Location: Mackay, QLD

by BNA » Wed Mar 13, 2013 11:10 pm

BNA
 

Re: Carbon Disc rotors

Postby AUbicycles » Wed Mar 13, 2013 11:10 pm

This may be of interest, I had contact a little while back with Kettle Cycles on the Carbon Fibre disc brakes after Michael shared the link.

Christopher BNA: Can you provide an indication of lifespan of the rotors?

Aaron Kettle Cycles: We believe that is basically an impossible questions. As a friction surface, the rotors will last indefinitely.
People crash, they bash their bikes on things loading and unloading. Drive into low overheads. Some ride a lot and some are garage queens.
We believe you should get three years of hard use. Mud and grime can foul up the transfer film layer, but it is easily cleaned and re-burned.
Pads will wear, but they are cheap.


Christopher BNA: Are there specific requirements or recommendations for the brake pads used?

Aaron Kettle Cycles: We manipulate the properties to work with stock pads from Shimano, Avid and Formula and most of the rest.
We will release carbon pads for extreme use and those who wish for that OTB static bite. We like momentum on the trail and really went after more modulation, that is personal preference so we have pad testing complete and ready to produce en masse if the feedback is that cyclist like that excessive static bite they are use to. If our cars were that touchy we'd bounce our heads off the windshield on a slight brake check. We think this is better, but again, it's up to the consumer and we are prepared.


Christopher BNA: Is Laminar Sheer an issue or consideration - and is there a temperature limit / rating?

Aaron Kettle Cycles: It is not, and they are formed at around 1000c, the rotor will take more than your fluid or pads will. They are functional long after steel would be saturated with heat.
We have proven that in testing. We have posted the baking pictures on facebook of cherry red rotors. The friction ring at 4-5mm thick is ready for years of use on a track car/cycle. Speed is everything and they exceed 150mph to stop without flinching.
User avatar
AUbicycles
Site Admin
Site Admin
 
Posts: 9138
Joined: Tue Aug 23, 2005 2:14 am
Location: Sydney

Re: Carbon Disc rotors

Postby MichaelB » Thu Mar 14, 2013 12:14 pm

Kettle SiCCC rotos with Parabox calipers on a Caletti cycles roadie

Image

From CN NAHBS summary
User avatar
MichaelB
 
Posts: 6830
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

Re: Carbon Disc rotors

Postby barefoot » Thu Mar 14, 2013 2:05 pm

DavidL wrote:- For the testing here of temperatures here mounting thermocouples inside pads although would be cool and get lots of hits on the net, is probably over complicating it a little. An infrared or hand-held probe on the rotor as the bike comes to rest should suffice for trying to determine if brake fluids are going to boil or not. We are just testing if it is 100, 200, 300 or 400 deg. C, not trying to design a system here.


Sorry, pad thermocouples is just the way I usually do things (in my day job as a brake test engineer ;-) ), so it's the first way I imagine doing the test. Especially since I can just pinch the sensors and logger from work.

Infrared on a polished metal surface is horribly unreliable. Emissivity is lousy. Contact might work, but you have to consider that there's very little thermal mass in a bike rotor, so bringing an ambient temperature sensor into contact with it - even a small one - is going to suck heat out pretty quickly as it comes to equilibrium.

One thought I just had is a rubbing thermocouple. We use them occasionally. They self-heat to some extent, depending on contact pressure, but that's only a real issue when you're trying to measure wear rate at 50°C and need to cool the damn thing down between stops. At the temps we're aiming for here, a rubbing thermo would do nicely.

- Mt Buninyong isn't really any where near big enough to do a proper heat test.


There's not a whole lot of thermal mass in a bike brake, so it's not going to take very long at all to heat up as much as it's ever going to.

Also, be aware that the Road Nationals course only climbs half of Mt Buninyong. There's another 150m elevation in 2.5km to be had on the top half of the mountain. In total, I could drag a single disc brake for 300 vertical metres over 5.5km down a full descent of Buninyong... and that should be more than enough to cook the hell out of a brake.

Besides, if Mt B isn't big enough... I have to travel a long way to find a mountain that is. Buninyong is about as big as it gets in my backyard.

- Brake fluids are available up to well over 300 deg. C which is going to be very hot at the rotor as in automotive applications rotor temps can be 5 times fluid temps which is going to be well beyond happy working temps of bike rotors. (though vauge physics here, I am trying to suggest that IF the fluid was to boil, it would most likely be a secondary failure)


"5 times" is not meaningful when you're measuring on a scale with an arbitrary zero point, but your point is fair - the same point I was making earlier. If people are worried that fluid is going to boil, then they should be really worried about the temperature of other parts of the brake system. Worst case, fluid isn't going to boil until a couple of hundred degrees, possibly much higher. Unless you're continuously dragging the brake for long enough that the entire system comes to equilibrium, the working parts of the brake will be much hotter.

In automotive terms, the effect is more pronounced because the system is so much bigger. I run tests where the brake is quite hot for a long time (200-300° at the rotor for maybe an hour, spiking to 500°), and the backplate won't get to 100°... let alone the caliper body and fluid. But that's with a 10mm chunk of non-conductive friction material insulating the hardware from the real action. Thinner metallic pads on bike brakes won't be so lucky, but you're still not going to see fluid temperature anywhere near the pad/rotor interface temperature.

I'm used to dealing with pad materials that don't change appreciably in friction until rotor temps upward of 400°C, and some that are only mildly troubled by 800°C temperatures that will cause permanent microstructural damage to a cast iron rotor. Plenty of world wide experience on mountain bikes says that it's possible to fade a disc brake; so even if we only get fairly average friction materials, we're still talking working temperatures of 400°C+ at the limits of what cycle disc brakes can do.

Somebody else can do the validation testing of plastic rotors at those temperatures for me.

Though some testing data would be great to see, especially with a couple of different rotor designs.


I think operator behaviour is going to be a much bigger determinant of operating temperature than any hardware variable. If I drag a brake down a steep hill for several minutes (like the celebrated crasher in that celebrated magazine story did), then I'm going to get my brakes much hotter than if I pulse the brakes, or alternate front and rear, or sit up and roll free and let the aerodynamic drag moderate my speed between brake applications, or do anything at all to moderate my brake temperature.

Same in a car. I can fade my brakes and crash if I try hard enough. Doesn't mean that disc brakes are a bad idea in a car - it just means that I'm an idiot.

tim
User avatar
barefoot
 
Posts: 988
Joined: Tue Jan 29, 2008 10:05 am
Location: Ballarat

Re: Carbon Disc rotors

Postby MichaelB » Sat Mar 16, 2013 9:04 am

Here is some feedback from a guy in the US using the carbon rotors on a roadie

http://ridingthecatskills.com/
User avatar
MichaelB
 
Posts: 6830
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

Re: Carbon Disc rotors

Postby AndrewBurns » Sat Mar 16, 2013 9:16 am

I like the shimano ice-tech calipers with heatsink fins on the brake cylinders. Makes sense to me, assuming you're going at a decent clip as the brake fluid starts to heat up the amount of power you could dissipate into the air through a small heatsink would be enormous, you'd definitely have a failure somewhere else in the system before the fluid boiled then.
Image
AndrewBurns
 
Posts: 996
Joined: Sun Oct 09, 2011 1:36 pm

Re: Carbon Disc rotors

Postby trailgumby » Sat Mar 16, 2013 9:50 am

MichaelB wrote:Here is some feedback from a guy in the US using the carbon rotors on a roadie

http://ridingthecatskills.com/


"Let me repeat this, though, in case it wasn’t clear: you must follow the bedding in procedure or you will die." :lol:
"People have a right to their own opinions, but not their own facts. Evidence must be located, not created, and opinions not backed by evidence cannot be given much weight." -- James W Loewen

http://www.facebook.com/Drive2WorkDay
User avatar
trailgumby
 
Posts: 10309
Joined: Sat Jan 03, 2009 4:30 pm
Location: Northern Beaches, Sydney

Re: Carbon Disc rotors

Postby MichaelB » Sat Mar 16, 2013 12:56 pm

trailgumby wrote:
MichaelB wrote:Here is some feedback from a guy in the US using the carbon rotors on a roadie

http://ridingthecatskills.com/


"Let me repeat this, though, in case it wasn’t clear: you must follow the bedding in procedure or you will die." :lol:


Classic case of RTFI :D
User avatar
MichaelB
 
Posts: 6830
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

Re: Carbon Disc rotors

Postby MattyK » Sat Mar 16, 2013 8:16 pm

I would say the same thing about my BB7s though...
User avatar
MattyK
 
Posts: 1420
Joined: Fri Oct 01, 2010 1:07 pm
Location: Melbourne

Re: Carbon Disc rotors

Postby MichaelB » Fri Mar 22, 2013 12:53 pm

Well, this has gone a bit quiet, so thought I'd post this which may (or may not) address some concerns, or raise even more Q's.

This came from the WW forum thread in the MTB section, and is from one of the Kettle founders ;

joshuagore wrote:I think it is fairly natural to be skeptical of emerging technologies so it was no surprise when many people assumed we were simply selling high temp traditional epoxy based carbon laminate, cut to a rotor shape. The truth we felt was clearly spelled out in our name. SiCCC, Silicon Carbide, Ceramic, and Carbon Fiber. I understand it's hard to believe that a little startup could be producing product similar to that of Brembo, but its not an impossible notion especially if you compare $/gram compared to Carbon Ceramic brakes available for automotive applications. This is not to say we are selling a Brembo like product, our chemistry, and manufacturing process had to be very different to fit the form factor required for a bicycle, but they do sell the closest comparable product.

Obviously we have a vested interest in protecting our IP(I do mean our IP, as in we own it, not filed by someone else and licensed) and keeping things a trade secret for as long as possible. Those 18 months we get to wait before our patents are published are very valuable. Yes Shimano, and SRAM can purchase our rotors and reverse engineer to their hearts content, but the process we take to get to that composition is unique, and therefore will remain a secret.

We really had hoped to expound more in both video and text, but the kickstarter success meant we had to focus 100% on production. This meant 14+ hour days of manufacturing. We hope to do a better job in the future detailing the advantages of our material and goals for the future, but currently our focus has been on manufacturing, a lot of people took a chance, and it is our goal to fulfill orders before trying to sell more through marketing. We had some setbacks, bounced back, and are on track, and we appreciate the patience. I fully accept critics, and even skeptics as part of the deal, but the cynicism helps nothing. We started as 2 guys who's goal was to design product which made for a better ride, this does not mean we are owed anything, this does not mean we deserve anything, it just means were passionate cyclist like the rest of you.

Here are some photo's which you have likely all seen, but require explanations:
Image
In this photo the rotors are seen glowing red. This is part of the manufacturing process and was simply posted to show that this is not normal epoxy, as obviously there are no epoxies not even thermoplastics which can withstand the heat required to make carbon glow red. I won't explain what part of the process this is, or why we do it, but suffice to say its required to create a product which can withstand temperatures far in extreme of the friction created on even the most rigorous descents. We have yet to see, and do not expect anyone to experience a glowing red rotor in any real world situation, as cool as it might be, most pads can hardly handle those temperatures.

Image
This picture is of a dyno run at 1500w. We are a small company and we needed a multi purpose test rig which allowed us to do both road and bench testing. We created a bench dyno and a road rig by using a trike and a custom built brushless hub motor. In this picture the rotor is being brought to over 800f and held at this temperature through pulsation, and then cooling times were recorded. We also tested failure, but were unable to reach a point at which failure could be accomplished with the friction capable from a bicycle tires traction patch. Our tests were similar to EN/DIN with the exception being we tested at a higher wattage, but that was simply because we had no method of limiting to a lower wattage accurately.

http://www.youtube.com/watch?v=MSnJ9ahl5pQ
This video was recorded more as a gag than anything else. I was joking around about the composition of our rotors and suggested we should load it up in a die grinder and cut some metal. I did and this ended up happening. Like a grinding wheel, when the rotor hit the aluminum core of the ICE Tech it deposited material on the SiCCC rotor. Nothing really interesting here, just what guys do at 2am working late to amuse themselves.

I appreciate your time and will do my best to answer questions.
Josh
Co-Founder Kettle Cycles



Full thread here for those that are interested ;

http://weightweenies.starbike.com/forum/viewtopic.php?f=1&t=112647
User avatar
MichaelB
 
Posts: 6830
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

Re: Carbon Disc rotors

Postby Mulger bill » Fri Mar 22, 2013 9:57 pm

Thanks Michael, wonder how they'd go with Spyres...
This looked promising...
User avatar
Mulger bill
Super Mod
Super Mod
 
Posts: 25815
Joined: Sun Sep 24, 2006 2:41 pm
Location: Sunbury Vic

Re: Carbon Disc rotors

Postby MichaelB » Sat Mar 23, 2013 7:03 am

Mulger bill wrote:Thanks Michael, wonder how they'd go with Spyres...
This looked promising...


It's a promising start, but need to see more feedback from independent users.

I'm hoping that BNA gets some rotors to test soon.
User avatar
MichaelB
 
Posts: 6830
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

Re: Carbon Disc rotors

Postby jacks1071 » Sat Mar 23, 2013 11:23 pm

I inspected some carbon bicycle rotors in Taiwan. Only one supplier had them on display.

They looked same as the Kettle ones except they had ceramic inserts where you would normally have holes or slots.

The supplier showed me the test results from SGS who is one of the big testing companies in Taiwan used by much of the bike industry.

I was pleased that he'd showed me some FAILED reports and he discussed what was changed in the design from their experience.

Unfortunately the testing for the standards passed were quite a long way below what I put the rotors through on our tandem in terms of both weight and speed.

The supplier did say he'd hadn't put the 203mm rotors through testing yet, and he would have them tested with the weights and speeds I provided from our tandem and he'd let me know.
User avatar
jacks1071
 
Posts: 2944
Joined: Thu Aug 20, 2009 9:47 pm
Location: Mackay, QLD

Re: Carbon Disc rotors

Postby MichaelB » Sun Mar 24, 2013 7:04 am

Thanks jacks1071, dangling all of that useful info but no pics or other details ?

What the ?!?!?

:D
User avatar
MichaelB
 
Posts: 6830
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

Re: Carbon Disc rotors

Postby jacks1071 » Sun Mar 24, 2013 4:52 pm

MichaelB wrote:Thanks jacks1071, dangling all of that useful info but no pics or other details ?

What the ?!?!?

:D


One moment please :-)
User avatar
jacks1071
 
Posts: 2944
Joined: Thu Aug 20, 2009 9:47 pm
Location: Mackay, QLD

Re: Carbon Disc rotors

Postby jacks1071 » Sun Mar 24, 2013 5:24 pm

Here you go:

Image

The 160's have passed the various "standards" - seemed like the other sizes were untested at this time.

You'd think if Kettle had done independant testing they'd have referenced the test results on their site? I was unable to find them.

The brochure image seems to have the bottom cut off it, I've shared it off our facebook page. Please join there if you want to view the entire image.
User avatar
jacks1071
 
Posts: 2944
Joined: Thu Aug 20, 2009 9:47 pm
Location: Mackay, QLD

Re: Carbon Disc rotors

Postby trailgumby » Sun Mar 24, 2013 8:10 pm

jacks1071 wrote:Here you go:

Image

The 160's have passed the various "standards" - seemed like the other sizes were untested at this time.

You'd think if Kettle had done independant testing they'd have referenced the test results on their site? I was unable to find them.

The brochure image seems to have the bottom cut off it, I've shared it off our facebook page. Please join there if you want to view the entire image.


Design flaw: the spokes run the wrong way
User avatar
trailgumby
 
Posts: 10309
Joined: Sat Jan 03, 2009 4:30 pm
Location: Northern Beaches, Sydney

Re: Carbon Disc rotors

Postby Nobody » Sun Mar 24, 2013 9:11 pm

So as the disc spins anti-clockwise as we are looking at it as per normal disc operation, the brake clamps to prevent the hub rotating. So the force of the hub trying to continue would be pulling the spokes. How is this a design fault?

On the Avid discs I have, the hub spokes are in the other direction. Either Avid has a design flaw or there is something I'm missing. Why would it be better to compress disc spokes rather than stretch them?
Nobody
 
Posts: 6640
Joined: Thu Sep 18, 2008 12:10 pm
Location: Sydney

Re: Carbon Disc rotors

Postby Mulger bill » Sun Mar 24, 2013 9:32 pm

Methinks you'll find that all non floating rotors are that way Nobody, with a directional arrow or this side out label attached. No idea 'bout the science behind it but I'm sure the boffins did their sums.

Shaun
User avatar
Mulger bill
Super Mod
Super Mod
 
Posts: 25815
Joined: Sun Sep 24, 2006 2:41 pm
Location: Sunbury Vic

Re: Carbon Disc rotors

Postby jacks1071 » Sun Mar 24, 2013 11:36 pm

Mulger bill wrote:Methinks you'll find that all non floating rotors are that way Nobody, with a directional arrow or this side out label attached. No idea 'bout the science behind it but I'm sure the boffins did their sums.

Shaun


I wouldn't know which way is or isn't correct. I wouldn't assume that the brochure picture is the final production version.

I do know that the 160mm rotors had gone through testing at SGS as the guy showed me the actual report. That type of testing doesn't come cheap, I've seen SGS reports before and it was the real deal.

He also said the bolts should be done up to 6nm which was comforting as I think one of the other carbon rotor manufacturer's said 4nm which seems pretty light on to me. If you have rotor bolts come loose on these almost for sure I think they'd come appart.

The rotor in the brochure passed 3x different disc rotor testing standards, they had the reports on hand and I'm confident they'd be ok on a single bike.

He also had 203mm rotors there and I had cash in my hand to buy one and he told me to wait until he tests it to the higher weight and speed I require for our tandem before he'd let me buy a sample.
User avatar
jacks1071
 
Posts: 2944
Joined: Thu Aug 20, 2009 9:47 pm
Location: Mackay, QLD

Re: Carbon Disc rotors

Postby Nobody » Mon Mar 25, 2013 6:27 am

Mulger bill wrote:Methinks you'll find that all non floating rotors are that way Nobody, with a directional arrow or this side out label attached. No idea 'bout the science behind it but I'm sure the boffins did their sums.

Shaun
No doubt they are the same, I just hope someone in the beginning didn't get it wrong and everyone else has copied the original style so as to not look different. Stranger things have happened.

jacks1071 wrote:He also said the bolts should be done up to 6nm which was comforting as I think one of the other carbon rotor manufacturer's said 4nm which seems pretty light on to me. If you have rotor bolts come loose on these almost for sure I think they'd come apart.
I suppose you could run spring washers or stronger locking compound if it concerned you.

jacks1071 wrote:He also had 203mm rotors there and I had cash in my hand to buy one and he told me to wait until he tests it to the higher weight and speed I require for our tandem before he'd let me buy a sample.
Wise move on his part. As much as you would probably be the perfect test bed, it could be an ugly law suit and bad PR for him too.
Nobody
 
Posts: 6640
Joined: Thu Sep 18, 2008 12:10 pm
Location: Sydney

Re: Carbon Disc rotors

Postby MichaelB » Mon Mar 25, 2013 7:39 am

Interesting that the construction seems to be completely different to Kettle's rotors.

Would have been great to see a picture, as it isn't clear from the brochure pic as to how it is constructed.

Am I correct in assuming that the light coloured 'holes' (or what would normally be slots in a steel rotor) are ceramic pucks, and this is the friction surface that does the braking ?

If that is the case, there is a big land/sea (to steal a phrase from F1) area diff where there isn't much friction material (land) compared to rotor (sea).

Or have I got it wrong ?
User avatar
MichaelB
 
Posts: 6830
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

Re: Carbon Disc rotors

Postby MichaelB » Mon Mar 25, 2013 7:41 am

Mulger bill wrote:Thanks Michael, wonder how they'd go with Spyres...
This looked promising...


Thought about it some more, and whilst all of the reports are similar in that it takes some time, in addition to the bedding in, to get good stopping power, no one has done back to back tests of the stopping distance of the steel vs carbon rotors.

Feel is one thing, but actual stopping distance is one of the key measures.
User avatar
MichaelB
 
Posts: 6830
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

Re: Carbon Disc rotors

Postby Nobody » Mon Mar 25, 2013 8:28 am

MichaelB wrote:Feel is one thing, but actual stopping distance is one of the key measures.
Can't see it being an issue for a road bike. As long as it can get the back wheel off the ground, stopping distance is going to come down the road surface, front tyre and weight distribution.

After all, if we really cared enough about stopping fast, we'd all be riding flat bar bikes with short stems, or MTBs (longer center to front, better weight distribution, lower tyre pressures, etc).
Nobody
 
Posts: 6640
Joined: Thu Sep 18, 2008 12:10 pm
Location: Sydney

Re: Carbon Disc rotors

Postby MichaelB » Mon Mar 25, 2013 8:57 am

Nobody wrote:
MichaelB wrote:Feel is one thing, but actual stopping distance is one of the key measures.
Can't see it being an issue for a road bike. As long as it can get the back wheel off the ground, stopping distance is going to come down the road surface, front tyre and weight distribution.

After all, if we really cared enough about stopping fast, we'd all be riding flat bar bikes with short stems, or MTBs (longer center to front, better weight distribution, lower tyre pressures, etc).


I was referring to the fact that a majority seem to be reporting that the outright power doesn't 'appear' to be the same (or words to that effect).

But none of this is backed up with any fact. Do they feel that they don'ty brake as hard due to the friction profile ? That there is different sound ? That the lever feel is different ?

Who knows until someone does some back to back tests, i.e. 5 stops at a series of speeds, and measures the stopping distance as a starting point.

That's what I'd be doing if I got them.
User avatar
MichaelB
 
Posts: 6830
Joined: Tue Feb 20, 2007 8:29 am
Location: Adelaide, South Australia

PreviousNext

Return to Buying a bike / parts

Who is online

Users browsing this forum: Majestic-12 [Bot]



Popular Bike Shops
Torpedo 7 Torpedo7 AU
Ground Effect Ground Effect NZ
Chain Reaction Cycles CRC UK
Wiggle Wiggle UK
Ebay Ebay AU

“Bicycles BNA Twitter
“Bicycles BNA Facebook
“Google+ BNA Google+
“Bicycles BNA Newsletter

> FREE BNA Stickers
> BNA Cycling Kit