# Finally, a functional extralight centerlock rotor



## tehan (Jan 22, 2007)

*Finally, a functional extralight centerlock rotor project*

I have always seen opinions and comments that there is actually no light, functional, well performing centerlock rotors. Shimano splines user has been left only with one or two choices.

Now it's time to change that. I want to present truly full floating centerlock rotors from absoluteBLACK. Absoluteblack - lightest centerlock rotors

hard data:
Mass: 95g +/-1g
Spider: aircraft spec. solid billet cnc machined 7075 T651 aluminium
Spider Finish: type II anodizing, black
Rotor: martensitic 420 stainless steel, laser cut, grinded, vacuum heat treated, 1.7mm thick
Bolts: custom M4, Ti6Al4V (grade 5) titanium

It is actually first true full floating rotor in the bicycle industry. This means that friction ring has constant controlled ability to move from side to side and expand when heated. This greatly reduce squeal in wet problems, damps harmonic vibrations and prevents thermal distortion or warping.

* this rotor is the lightest centerlock rotor in the world, but still maintain greater braking surface than any light iso rotor.

* this is actually the first rotor where you can get the friction ring off by yourself and change to any other on our site (currently 2) - no company offer that and we are already prototyping even lighter ones to offer in the future.

* 160mm and 180mm rotors will maintain same spider, so there is no need to buy whole rotor if you decide to go up with size. You can buy friction ring for 25% of the cost of complete rotor. (180 will be available soon)

* almost rub free design as friction ring can move side to side between pads.

* reduced squeal in wet - same reasons as above. In practice you can see(hear) a significant difference riding with these compared to hope floating, shimano xtr or new formula centerlock.

You can watch a small teaser of it's performance here: 





More photos, some answers to ongoing discussion here:
absoluteBLACK Centerlock Bremsscheibe - Light-Bikes Forum
(topic is mostly in german language, but all my answers are in english)

if you have any questions or concerns just let me know. There is also tons of information on our site, so i strongly recommend to go there for answers first. Absoluteblack - lightest centerlock rotors

Marcin
absoluteBLACK


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## skyfire1202 (Jan 21, 2008)

Nice! When will the ISO rotors be available in your site?


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## Mattias_Hellöre (Oct 2, 2005)

Hi Marcin, that´s nice you are to able to offer a product that meets most criterias weightweenies are after.

As you see, the price is a bit high due to manufacturing costs plus profit - right?

That´s the same thing I told you before.

That´s very hard to offer a product with advanced machining at china low price without a downgrade in quality and short runs are very expensive.

Anyway, good luck with that and I may buy 2 or 4 in the future.


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## litany (Nov 25, 2009)

That looks pretty sweet. You say " Money collected that way goes into building another prototypes and so on." what sort of prototypes do you look forward to working on? Are you going to continue working on rotors or maybe something else?


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## tehan (Jan 22, 2007)

Hi everyone, 
Thanks for all the comments.

I will try to reply in order.
*ISO rotors* - these should be within few months.

*Mattiass *- You run similar business, so you know how it looks like. Yes, price is on high side because of the cost of milling the spider; which is extremely high. 
As i stated on my site, i will never try to cut the corners, so am creating best possible design. This unfortunately means high production costs, but from the other hand it comes with excellent quality and this unique factor
This is my passion, so there is never such thing like too expensive bike part. I fully realize that these parts are not for everyone, but that was never my intention. We have enough Chinese products on the market. We need something more unique like mine or your products - otherwise world would be boring.

*litany* - i have still few more plans for rotors and then will move to something else. Like 240g pedals or cogs... enjoy


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## Mattias_Hellöre (Oct 2, 2005)

Tehan: thanks, regarding cogs and chainrings, I´ve learnt one thing or two in this type of business, a high quality as selling point and a justified high price is no go, people think Shimano is highest quality and more expensive than Shimano and NOT titanium, you will sell very few rings.

Unfornutately that´s my experience, 90% of all chainrings I sell is titanium, you can place what price you want and they will sell, aluminum - forget it.


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## 92gli (Sep 28, 2006)

tehan said:


> * almost rub free design as friction ring can move side to side between pads.


How ?


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## sergio_pt (Jan 29, 2007)

Looks cool mate! good job!

where is that friction ring?? curious about that too.

Another question: titanium rotor should have less stopping power that stainless steel, so what is the friction coefficient in the steel rotors for comparison?


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## tehan (Jan 22, 2007)

HI again,
Mattias - chainrings were just an example. These are mainly for my own project bikes and are not for sale as most of the are in odd teeth count to fit my riding style.

92gli - don't really know what you are asking but: 
A- as to rub free. Because whole friction surface can move it can align properly between pads and does not rub anymore (after first rotation of the disc)
B- how does it work? on my movie first photo shows how it is built. Bolts actually leave 0.1mm gap to the friction surface allowing it to move. Bolts are only for the purpose of keeping whole steel surface in place. 


sergio_pt - friction ring = friction surface= rotor. This can move against black spider only in one direction (like from pad to pad in caliper) but can't move in direction of braking. 
To answer on your second question we would have to go deeper in material properties than just friction coefficient. In general titanium has greater friction coefficient than steel in regards to braking pads. But it has much less heat capacity and conductivity, so all in all it heats up quicker making braking a bit less efficient, as pads heats up quicker and this changes it's braking properties. 
But no one uses bare titanium as friction surface. It always has a treatment and this in turn changes it's properties again (there is whole "magic" happening). You can tweak a bit these properties making braking efficiency more like stainless steel. There is still a problem with heat capacity however, so that's why such rotors are rather for XC racing and for lighter riders who will not generate so much power on the disc to heat it up that quickly.
On the side note - centerlock rotors are with stainless steel friction surface. My new iso rotors will be titanium only.


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## Edu24h (Oct 30, 2006)

Why iso rotors only with titanium surface?


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## crazy8 (Apr 21, 2009)

On your site it says the black ISO ti rotors are coated with a black ceramic. How does the coating hold up on the breaking surface and with ceramics having such low friction properties what material is used for the pads? Does the insulating properties of the coating allow enough heat to build up to give good breaking?

Thanks,


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## ginsu2k (Jul 28, 2006)

BTW, SOLIDWORKS is NOT REAL FEA SOFTWARE!!! IT EVEN WARNS YOU NOT TO TRUST THEIR RESULTS!

Get something real like CATIA V5 or ANSYS! AND YOU NEED TO DO REAL PRODUCT TESTING to VERIFY NUMERICAL RESULTS!

Titanium rotors? I think people are nuts and just want to brag about having ti rotors, WRONG MATERIAL FOR A FRICTION SURFACE! You even pointed this out in your posts. 

DO YOU EVER SEE TITANIUM ROTORS FOR AUTO RACING? WHERE COST IS NO OBJECT! HMMMM. WONDER WHY?

Good luck selling those!


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## tehan (Jan 22, 2007)

hi again,
We have some interesting posts here today.

Crazy8 - We both know i can't answer your questions as i would pass all the secrets. All i can say is the only common part with your type of ceramic is word "ceramic" itself. I do appreciate your interest but can't say much. To give you some ground - my type of "coating" is not sprayed on or vapor deposited. 
If you do some research you will notice that some ceramics are actually better heat conductors than steel or some other metals. Same is with friction. It depends on many factors which can be controlled during growth of ceramics. But i agree that friction coef. is minimally smaller that the one for steel. 
Carbon-Ti use similar technique to grow their ceramics but ceramics itself is different.

Edu24h - right now it's just because it's cheaper using steel. If someone decide to get tiatnium surface i will offer such.

ginsu2k - could you stop using capital letters it would be easier to read. thanks
This step is just for validating my design. There is few other steps involved in calculating/evaluating this design by a third party company. So not to worry. Besides there is loads of real life testing done before something goes on my site. 
On the side note it's worth to mention that HOPE technology use only Solidworks and only CosmosWorks for evaluating their projects. So it's not that bad at the end. (please check their website)

As to titanium for a disc material. If you look carefully into patent database you will find that each respectful company have at least 2-3 patents for titanium and aluminum matrix rotors. Thing is it is extremely expensive to produce right now and it's not for everyone to use - i mean there are only certain applications of such rotors.

As to friction surface - yes titanium is not the best material as friction surface *Itself*. That is why "coating" is needed. It changes completely friction surface properties and for certain applications is fully enough to work as a disc brake (ie. light riders in XC use).
Please understand that such type of rotors are not for everyone, like not for everyone are racing pads or calipers in the car as "normal" person would not stop the car in regular traffic.

There is already few companies selling ti rotors like Carbon-ti and the do very well since few years.


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## crazy8 (Apr 21, 2009)

Understood, I don't expect you to divulge secrets. As you said I can figure it out for myself. I wish you success with ideas and business. I'm believe in the small grass-root entrepreneur.

I found this today in a news alert from Lightbike. 
*http://www.lightbike-magazine.es/index.php?option=com_k2&view=item&id=527%3Aabsolute-black-el-disco-centerlock-m%C3%A1s-ligero-del-mundo&Itemid=25*


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## Edu24h (Oct 30, 2006)

tehan said:


> hi again,
> We have some interesting posts here today.
> 
> Crazy8 - We both know i can't answer your questions as i would pass all the secrets. All i can say is the only common part with your type of ceramic is word "ceramic" itself. I do appreciate your interest but can't say much. To give you some ground - my type of "coating" is not sprayed on or vapor deposited.
> ...


I don´t understand it, if steel surface is cheaper why only in titanium for Iso rotors?


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## Mattias_Hellöre (Oct 2, 2005)

ginsu2k said:


> BTW, SOLIDWORKS is NOT REAL FEA SOFTWARE!!! IT EVEN WARNS YOU NOT TO TRUST THEIR RESULTS!
> Good luck selling those!


Please, stop use capital letters and you have proven yourself as hot air, no one will listen to you more, no backing up of your words, Dassault Systemes who owns Solidworks does own CATIA too, so SW with 1.4 million users all of them spits out improper products?

I paid full license (approx 10.000 euro) for the license and use it with pleasure every day.

Please go biking NOW.


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## tehan (Jan 22, 2007)

Edu24h- It's simple. Centerlock rotor with Ti surface will cost above £240/pcs so right now i don't have it officially on offer. But don't have a problem producing one.

Why no steel iso rotors? I have made an effort of creating something special and want to keep it that way.


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## sergio_pt (Jan 29, 2007)

We need someone to make a test ans a good review to the titanium rotors. 
It can be me if you want.


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## Mattias_Hellöre (Oct 2, 2005)

Tehan: I want to order one rotor for my Scale RC testbed.
Contact me at [email protected]


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## tehan (Jan 22, 2007)

Hi guys,
Thanks for great interest and willing to test however i clearly wrote that titanium rotors are not ready yet to be commercialized. It will be soon, so be patient.

As to test. I have already made arrangements with 2 biggest magazines in Europe and one in Canada for testing, so they should be enough objective for you. Centerlock rotors are already tested by them right now, so you should see some reviews soon.

thanks


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## rockyuphill (Nov 28, 2004)

How troublesome is it to license the center lock standard from Shimano?


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## tehan (Jan 22, 2007)

Hi again,
rockyuphill - unfortunately i am not allowed to discuss about that. So i can't answer your question. sorry.


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## krzysiekmz (Nov 10, 2009)

Which Canadian magazine will have a pair to test?

Chris.


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## tehan (Jan 22, 2007)

Hi Krzysiek,
Can't say that either before publication. That's a standard agreement.


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## tehan (Jan 22, 2007)

Hi Again,
I got numerous emails asking about performance of these rotors in last couple of days. So to help answer them i decided to sell 6 rotors under special offer for members of this forum.

Deal is: 
You can buy each rotor for £99 with lockring for free (normal value £140 + £16) in exchange for review here on forum. 

Offer is valid only for people who are experienced riders and who will be able to provide constructive feedback. Ideally i want to sell these 6 to people from different "climatic" regions.


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## sergio_pt (Jan 29, 2007)

If you are talking about the titanium rotors and sell them for half the price, I'll be a candidate.


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## biketuna (Mar 28, 2008)

To rich for me. I'll keep my KCNC rotors.


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## tehan (Jan 22, 2007)

centerlock versions for now. 
Titanium rotors will be on offer soon - i have to finalize few more things. But certainly i can offer similar deal when ready for few pieces.


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## tehan (Jan 22, 2007)

built myself a new, more appropriate wheel to match the rotor. hope you like it

Facebook


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## Satanic Pizza (Feb 28, 2012)

Hi Tehan:

This part of your description on the ISO rotors has me curious:_ "Unlike any other, this one actually grows into and out of parent material under extreme heat and pressure, making it almost impossible to wear out."_ The wording makes it sound like the ceramic braking surface will last a very long time, but a specific expectation is not given. What would you say the expected service life for the rotor under normal use will be; or if you do not have this metric, what about a comparison (ex. 'AB rotor will last x time longer than standard rotor') to a standard alloy rotor?

Has anyone taken you up on your 6 discounted rotors for testing?

Have any of the magazine tests been released yet?

They are beautifully designed parts, gorgeous.


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## firminite309 (Nov 2, 2011)

That´s the same thing I told you before.

That´s very hard to offer a product with advanced machining at china low price without a downgrade in quality and short runs are very expensive.

Anyway, good luck with that and I may buy 2 or 4 in the future.


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## tehan (Jan 22, 2007)

Hi,
So, i have not been here for a while as i have been working on something new.

I am now preparing to test new iso rotors. I should have them on my site in few months as only thing to test is spider (other parts have proved themselves with centerlock rotor).

These have exactly same full floating system for mounting the friction ring(rotor) as my centerlock ones. So bolts and friction rings are interchangeable between iso and centerlock spider.

The idea behind them is that you can swap spiders whenever you want to fit iso or centerlock system.

160mm iso rotor is 81g, so 11g less than centerlock. Same spider can accommodate as well 180mm friction ring(rotor). So if you want to move to 180mm you just need to buy a friction ring which is 30% of the whole disc price.
These should retail for £110.

click on picture to get full size.




to answer few questions. 
German BIKE magazin should have a test review in next issue. 
There is a review also in Norwegian magazine - terrengsykkel.no 
(but full test review should be in few months)
And there are 2 more to follow soon.

Forgot to answer about coating of titanium rotors.
This coating grows in special conditions - so it have a crystal form. I don't have any lab test done now to show how long it will last. But what i can say is that NASA is using this type of coating for most of titanium parts where friction is in action. 
This is by far the best solution to titanium wear and friction problem. Only down side is cost of making it as there are only few facilities in the world to be able to make it. 2 of them are in Europe.


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## tehan (Jan 22, 2007)

HI again,
here is the video showing really long descend on Madeira. So you can see how rotor performs in high temps.


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## sergio_pt (Jan 29, 2007)

Great job. 
Do you already have the tests from the magazines to show us?

Madeira is very nice. Portugal FTW! :thumbsup:


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## proto2000 (Jan 27, 2007)

Wow,
Ti is soft as aluminum but tuff as steel. Steel is real for braking surfaces. Period.


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## tehan (Jan 22, 2007)

proto2000 i may misunderstand your comment. .this is steel braking surface in this video.


I will show soon sergio_pt


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