MTB conversion to Disc Road bike

[carbonazza]

In your area, the descents are so flat and soft, you do not take any risk with relatively unknown discs( in cycling ) and unknown Ti bolts

Do you have a link for the discs? I speak Spanish, so I can have a look.
At Aliexpress tarif, I was wondering if I wouldn't convert all my screws to Ti, just for the weight weenies sake of it 

[SportingGoods]

Absolutely! Here is all the references:

Ti bolts from Aliexpress (note that you always get a slightly better price when ordering from the phone app):
https://fr.aliexpress.com/item/12pcs-Titanium-screws-disc-brake-bicycle-parts-t25-m5-10mm-Ti-Rotor-Bolts-Screws-For-Mtb/32734581115.html

And the Carbon ceramic rotors
https://www.alphamotocicletas.com/en/tienda/

Here is what they claim, the only section in English:

The lightest ceramic rotor brake for bikes in the world.
Enjoy the latest technology for manufacturing ceramic discs created by Alpha for superior performance and long life.

Alpha carbon brakes are available for any type of bike, Trial, Cyclocross, Road, Enduro, Downhill…

-More powerful and progressive braking.
-No vibrations.
-Ultra lightweight.
-Better resistance to high temperatures and exhaustion compared to conventional discs.
-Superior performance.
-Efficiency dry and wet.
-1.9mm thickness.
Manufactured in Spain.

[Patrick C.]

I might try it on the rear brake first

Thanks for sharing all the pics and reports on your conversion!

[SportingGoods]

Hold on any purchase till I confirm it is OK! I have just received the rotors. I plan to test it tomorrow, but it's so cold and the road are so frozen that I don't plan on hard braking 
So far so good, rotors came very quickly from Spain (1 week), they are perfectly flat, nicely cut and they weight 41 g (160 mm) as announced. The big question now, do they actually brake!!

Nice box


Interesting marketing claims on the back of the box (I hope it is 100% true!)


The rotors!


Close-up


As flat and true as can be


1.9 mm thick, as announced


82g the pair

[carbonazza]

Neat design. I look forward to see a picture when mounted.
Take care to not over-torque them

[SportingGoods]

So... last night I got started to prep everything for a quick test today. I pull out the rotors, torque wrench, T25 fitting. I take the front wheel off the road bike and... Oops, those are Centerlock 
I get 5 pair of wheels at home. 3 are centerlock hubs (I prefer this design, but moved away because the offer is not as large as 6-bolts). 2 are 6-bolts: the hubs to build my carbon tubular (un-built) and my MTB wheels. One more with my son's bike (24" MTB).

So, I get 2 options to test. The rear wheel on my MTB (front is 180 mm), or my son's bike 
You already know that this test will be poor, at best. I'll try anyway, not sure yet which test will tell me more about the quality of the rotors. Or... I mount my son's wheel on my road bike. It would fit (remember it's a 29" MTB frame ).

[SportingGoods]

Test completed. I don't recommend Carbon rotors.

Not a catastrophic failure but I understand now why rotors are made of metal. That's because metal can be bent. As I mentioned and showed in my pictures, the rotors are perfectly flat, on the table. But once mounted on the hub they are out of true. I used my torque wrench to tighten the bolts evenly at 6 Nm (recommendation from Alpha). Could be that my hub is not perfectly true or that when you compress the rotor the constraint causes warp. Don't know. The only thing I know is that because it is made of Carbon you can bend it. You just can't fix it. Period.

They don't rub badly, but they do. I could certainly massage them to stop rubbing (by a perfect alignment of the caliper and some magic spells) but this is not a robust solution.

Then, they seem to stop me (tried the front brake of my son's bike). I guess there is some breaking in that needs to happen, but they are a bit noisy (dry) and vibrate. Hopefully this is just because they are new.

So, again, I don't recommend Carbon rotors. Never, ever would I use these on a MTB. You hit a rock and they most likely break, leaving you w/o brake. I'll try to fit them on my road bike once I have my carbon wheels built, but if I had the option to send them back I would.

[carbonazza]

So, again, I don't recommend Carbon rotors. Never, ever would I use these on a MTB. You hit a rock and they most likely break, leaving you w/o brake. I'll try to fit them on my road bike once I have my carbon wheels built, but if I had the option to send them back I would.

Wow... that didn't pan out as planned
Did you contact the builder about these issues?

For breaking the disc, I would have been more optimistic.
If you hit a metal disc it would probably bend enough to not be rideable nor fixable.
So not a big difference in the end.

[SportingGoods]

Test is over, and I've already requested my money back 
For those who don't speak Spanish they can use Google translate.
http://www.foromtb.com/threads/discos-de-freno-de-carbono-alpha-rs-cuidado-con-ellos.1366597/

Not taking any risk. Lucky I paid with my American Express card, if they don't send the money on their own I'm protected 90 days past the purchasing day.

[carbonazza]

The pictures speak for themselves. The disc explosion is scary.
I understand why you don't want to test them any further.

I didn't read the whole 22p thread.
But at the end a guy talks about some other brands that can be trusted more:

WREN:
https://www.bikerumor.com/2015/09/16/ib15-wrens-ultralight-ceramic-alloy-disc-brake-rotors-pass-testing-head-to-market/

SICCC:
https://www.bikerumor.com/2014/07/09/kettle-cycles-redesigns-siccc-carbon-fiber-brake-rotors-adds-colors-new-metallic-pads/
http://www.cxmagazine.com/cyclocross-kettle-cycles-sfl-siccc-ceramic-carbon-disc-brake-rotors

[SportingGoods]

Thanks for the link to potentially working Carbon discs but... I'll look into metal disc for now

I just want to mention that I recommend American Express credit card. Just got them on the phone and they have already locked the paiment. I just need to email them proof of communication with vendor and proof that the product is dangerous and they are going to contact the vendor on their own. Anyway, I keep my money!

[stockae92]

was the right kind of brake pads being used? those rotor were completely destroyed ...

[SportingGoods]

Alpha was never clear about pads in their communication. Before purchase I could only read they recommend "ceramic", "ceramic-organic" and "no metal". The problem is that "ceramic-organic" does not exist (at least I've never seen such thing), "ceramic" contain metal most of the time (so it is no good).
After purchase they finally replied to me, ignored my questions and just sent me that:

1-The Alpha RS disks are compatible with ceramic or organic ceramic pads; they should never be used with neither a metallic or synthetic compound nor Kevlar.
2- The disk was created to be used exclusively in six lock systems.
3- The disk can be mounted in any direction, although it is advisable to follow the instructions on our "use and rotor rotation" video.
4- The 6 screws applied on the disk must be of a tightening torque of up to 6 Nm.
5-When installing the brake pads, make sure the brake pad covers the entire ceramic track length.
6-For a safe installation and maintenance, make sure you keep your fingers away when the disc is operating.
7-Like any brake disk, it may reach high temperatures, be sure not to touch the disk when you get off after driving, note the disk can burn. To handle the brakes, make sure the disks are cold.
8- Before driving, check the disk and the braking system to assure all breaking operations are working properly.
9- When the disk is worn and it is 1.6 mm thick or less or when it is damaged or broken, the disk must be replaced.
10-Before driving, make sure that your brake pads are 0.5 mm thick or more
11- We suggest replacing the disk after 3 years of use or when observing a wear like the mentioned in the point 8.
12- Keep the disk away from grease and dirt, since these can cause the brakes fail.
13- It is advisable to use the brakes simultaneously and only when it is necessary, never
overheat the brake pad.
14-it is mandatory to use ventilated pads to ensure the proper operation of the disk.
15-Always perform a test drive when the pads are recently installed, we recommend to drive at least 40 km.
16- It is dangerous to jump with the brakes applied before reaching the ground, it can cause some damage.

So, now you see #14: ventilated brake pads are mandatory! Even more difficult to find. Impossible. So I emailed back, sending a link to 2 pads (on a Spanish website to make sure they understand). The first one (ceramic, not ventilated), the second organic and ventilated. They dropped one line to say I need to use the second one. Oh... so now, organic is recommended ?!?
I also ask a link to the video mentioned on #3. They never replied to me.

Also, they never got back to me since I asked for my money back. I had to ask AE to block the payment.

Honestly, whatever the pad you use these rotors will fail. Looking into these in more detail, they are not ceramic discs. Ceramic brakes, it does not delaminate.

A Spanish MTB website has also tested the rotors, same results after 2 rides!
http://esmtb.com/2016/12/16/discos-espanoles-ultralight-carbono-demasiado-bonito-para-ser-cierto/

These are just good for the trash. I believe it is made of carbon sheet and resin (maybe simply epoxy!).

[SportingGoods]

And the bike is as finalized as can be 

I've build my carbon wheels. Not even tested yet but you can already enjoy some pictures! You can also see the new bottle cage (carbon with a painting that fits my bike - not custom painted though) from Aliexpress. I finally find that the red line on the tires is too much. I'll probably won't repeat when they are worn out. They won't last till next year anyway (the bike already has 3000+ km, mileage goes fast on road bikes!).

And the bike as pictured is 7.5 kg. This includes pedals, bottle cage, latex in the tires and... a pump (hidden in the seatpost). My spreadsheet tells me 7235g w/o pedals, bottle cage and pump. That's most likely light enough for what I will do. And it's a disc brake bike, which is always a bit heavier, and don't forget it's a MTB 

Pictures now!

[carbonazza]

That's not heavy.
I've seen loads of top disc bikes with this weight.

Still waiting for the latest tech to build mine( either Shimano 9107 or SRAM HRD ).
I'm afraid their general availability will come like the Eagle last year, at the end of the season.