Page 1 of 5 1 2 3 4 5 LastLast
Results 1 to 25 of 113
  1. #1
    Cannondale Maros Team
    Reputation: vladxc's Avatar
    Join Date
    Jan 2009
    Posts
    258

    New Ashima Ai2 Rotors

    Hey guys,
    Did you heard about the new Ashima Rotors?
    There will be called Ai2 and the sizes available will be 160 and 180. Also there will be lighter by 23% than the current AiRotor and will be available from March 2012.

    The complete article here: Romanian weight weenies Blog Archive Noile discuri Ashima Ai2 It is in Romanian but using Google Translate will help you !




  2. #2
    Cannondale Maros Team
    Reputation: vladxc's Avatar
    Join Date
    Jan 2009
    Posts
    258
    No, a test will be performed and another article with a review will come.

  3. #3
    mtbr member
    Reputation: mtbnozpikr's Avatar
    Join Date
    Sep 2008
    Posts
    1,684
    That's not a bad looking rotor at all. I wonder how performance is. Did the article say anything about testing? I'm not feeling adventurous enough to try to translate Romanian right now.
    2012 Intense M9
    2012 Pivot Mach 5.7 Carbon
    2008 Look 595
    2007 Custom Litespeed Sewanee

  4. #4
    mtbr member
    Reputation: mtbnozpikr's Avatar
    Join Date
    Sep 2008
    Posts
    1,684
    Quote Originally Posted by vladxc View Post
    No, a test will be performed and another article with a review will come.
    Great, I look forward to it.
    2012 Intense M9
    2012 Pivot Mach 5.7 Carbon
    2008 Look 595
    2007 Custom Litespeed Sewanee

  5. #5
    "They Call Me Bone'z"
    Reputation: facelessfools's Avatar
    Join Date
    Aug 2008
    Posts
    1,609
    awesome! not a bad weight in comparison to my scrubs either!
    RAH!

  6. #6
    Cannondale Maros Team
    Reputation: vladxc's Avatar
    Join Date
    Jan 2009
    Posts
    258
    And these will be cheaper and more durable compared to the scrubs...

  7. #7
    manufacturer
    Reputation: tehan's Avatar
    Join Date
    Jan 2007
    Posts
    470
    but there is hardly any braking surface. It's not a problem creating very light rotor, but there is a problem creating light and fully working one...
    I've tried all these cheap light ones and in comparsion to for eg storm rotors there is only 50-60% their strenght. So by looking in this light on strom rotors i can be quicker on given distance because i can brake later and harder... so don't really see the point of having such one.

  8. #8
    The Cheater
    Reputation: Veda's Avatar
    Join Date
    Dec 2009
    Posts
    551
    The lightest rotor that is also still as good as the regular Shimanos, no actually better as they still bite even during rain, is the Quad Pulse XC. Very cheap, lasts forever, but prone to bending. I'm currently using the KCNC Razors but I might actually switch back to the Quads. This looks very similar to the Razors, usable only for XC...
    Titux X Carbon 2010 race 9.93kg
    Titux X 2009 "Deore 2012" training 11.55kg

  9. #9
    Hack Racer
    Reputation: Cheers!'s Avatar
    Join Date
    Jun 2006
    Posts
    2,554
    I used the Ashima AiRotor for many years. Works great. No issues at all. I still use two sets on a regular basis. 160mm and 140mm for both bikes. One with sintered metal pads, the other with organics.

    I'm very happy. All steel rotors perform the same in braking power.

    No different in power than Hope floatings.

    Braking power is not a function of its surface area. It is dependent on the rotor size and the pad material unless the rotor and pad overheats, which seldom do.

  10. #10
    manufacturer
    Reputation: tehan's Avatar
    Join Date
    Jan 2007
    Posts
    470
    Quote Originally Posted by Cheers! View Post

    Braking power is not a function of its surface area. It is dependent on the rotor size and the pad material unless the rotor and pad overheats, which seldom do.
    with such statement hardly none or no surface at all will perform same as full braking surface.
    Less surface under pad means greater braking preassure to generate same friction (and the grater the pressure the grater temperature is). Less material mean as well more heat generated per cubic mm on the existing surface. This is because you will try to acheive same braking friction on smaller surface.
    Of coure this is more complicated and more factors play a role here, but in general with such design you create micro overheating in points. So you think that braking rotor is not overheating but in fact it is. It heats very quickly to hight temp and cools down same quick due to lack of material - but it is still overheating.
    It's like heating the needle over lighter compared to heating a bigger steel plate. Neddle will overheat(glow!) in a metter of ceconds but it will cool down as quick - but this state changes material structure and overheats brake calliper.

  11. #11
    mtbr member
    Reputation:
    Join Date
    Apr 2009
    Posts
    992
    Quote Originally Posted by Cheers! View Post
    I used the Ashima AiRotor for many years. Works great. No issues at all. I still use two sets on a regular basis. 160mm and 140mm for both bikes. One with sintered metal pads, the other with organics.

    I'm very happy. All steel rotors perform the same in braking power.

    No different in power than Hope floatings.

    Braking power is not a function of its surface area. It is dependent on the rotor size and the pad material unless the rotor and pad overheats, which seldom do.
    +1. This was my experience also. I went from Alligator Windcutter's to Hope Floating rotors and then to Ashima AiRotor, and noticed very little difference in power between them.

    I will admit that the new Shimano rotors combined with new XTR brakes are VERY powerful.

  12. #12
    mtbr member
    Reputation:
    Join Date
    Feb 2007
    Posts
    2,327
    Quote Originally Posted by tehan View Post
    with such statement hardly none or no surface at all will perform same as full braking surface.
    Yes.

    Quote Originally Posted by tehan View Post
    So you think that braking rotor is not overheating but in fact it is. It heats very quickly to hight temp and cools down same quick due to lack of material - but it is still overheating.
    How do you know this?

    Quote Originally Posted by tehan View Post
    It's like heating the needle over lighter compared to heating a bigger steel plate. Neddle will overheat(glow!) in a metter of ceconds but it will cool down as quick - but this state changes material structure and overheats brake calliper.
    How is it like that?

    Cheers! is right. See Energy of Friction.

  13. #13
    Hack Racer
    Reputation: Cheers!'s Avatar
    Join Date
    Jun 2006
    Posts
    2,554
    Quote Originally Posted by tehan View Post
    with such statement hardly none or no surface at all will perform same as full braking surface.
    Less surface under pad means greater braking preassure to generate same friction (and the grater the pressure the grater temperature is). Less material mean as well more heat generated per cubic mm on the existing surface. This is because you will try to acheive same braking friction on smaller surface.
    Of coure this is more complicated and more factors play a role here, but in general with such design you create micro overheating in points. So you think that braking rotor is not overheating but in fact it is. It heats very quickly to hight temp and cools down same quick due to lack of material - but it is still overheating.
    It's like heating the needle over lighter compared to heating a bigger steel plate. Neddle will overheat(glow!) in a metter of ceconds but it will cool down as quick - but this state changes material structure and overheats brake calliper.
    Wrong. A brake rotor is homogenous. There is no such thing as micro overheating of points. The heat energy generated by two sliding surface is instantly removed from the surface to the rest of the brake rotor as steel is thermally conductive.

    Let me recopy an old post I made about this same argument years ago.

    frictional force is proportional to the applied normal force and is independent of the contact area.

    What we are analyzing here is kinetic friction (sliding friction) between the brake pads and the brake rotor. Normal force is applied via the hydraulic pressure that presses the pads against the rotor. There are only two things for you to consider

    1.) Normal applied force
    2.) coefficient of friction

    let's look at #1. Consider that the two surfaces at their microscopic levels. The normal forces applied creates a bonding between the atoms of the brake pad and the atoms of the brake rotor. This bond is stronger as the force applied goes up.

    For #2 we look it accounts for the number of contact points between the two surfaces. This is what the coefficient of friction is.

    Hence Force of Friction = (coefficient of friction)(Normal force applied)

    The surface area in essence is already considered in the Normal force applied. So when you push down on your brake pad the normal force is distributed across the surface that makes contact with the rotor. The density of the contact points is uniform across the brake pads so that means the formation of contact points depends on the normal force per unit area.

    Normal Force = Normal force over area * area
    Normal Force = (N/A)*A

    A larger contact area would give you more contact points (atomic wise), but each contact point would get less force. In other words since the force applied equals force divided by the area of contact, it works out that the increase in friction generating area is exactly offset by the reduction in force applied on each contact point.

    If you are still doubtful do an experiment. This is the exact demonstration my high school teacher did for me back in grade 11.

    Take a brick and place it lengthwise on your table. Tie a string through one of it's holes. Take a fish scale and hook it to the end of the string and pull it in such a way that the string is parallel to the table. Record down the force you are pulling with once the brick moves.

    Now take the same brick and place it with it's smallest face contacting the table. Retie the string near the center of gravity of the brick. Use the same fish scale and pull the same.

    You will note that the force required to pull the brick regardless of if it's on its biggest face versus its smallest face is the same.

    Coefficient of friction is determined by experiment/test. All the values that are referenced in the back of text books are obtained by sliding two surfaces together and accurately measuring the force required to get it moving, and the force required to keep it moving. The earlier determines the static coefficient of friction, and the later determines the kinetic coefficient of friction.

    The coefficient of friction stays relatively constant for temperatures we experience. If you make your rotor glow red or went mountain bike when it is -20C outside that is a different story.

    For example, the braking "power" of the ashima brake rotor shown in the video at the beginning is greater than the braking "power" at the end, because your rotor is now glowing red. If the brake caliper's input force was modulated such that it was only applied for brief moments at a time while letting both pads and rotors to cool and the disc stayed constant in speed the measured braking force would stay the same.

    This would be typical of normal riding conditions. If you believe that the type of riding you do has you needing to have the brakes applied at great force and for close to 3 minutes while you are continuing to accelerate than no brake designed for mountain bikes will be adequate for you.



    The only thing to worry about is if the designer of the brake rotor calculated the forces correctly such that the spider does not collapse or crack under the loads during braking.

  14. #14
    mtbr member
    Reputation:
    Join Date
    Feb 2010
    Posts
    1,475
    I've used the Ashima AiRotor, Alligator Aries, Hygia lightweight rotors and now 2012 HSX rotors.

    In the dry, for short braking distances, like your average XC course, they are almost all the same in terms of performance using organic or sintered pads.

    Where you'll notice the difference is:
    - in the wet; and
    - on long descents with lots of hard braking and stretches where the brakes need to be used almost continuously to control speed.

    In both of these circumstances I've found the rotors with less braking surface suffer from reduced braking power.

    The less thermal mass in the rotor, the quicker you can feel it heat up and start to fade. At the end of the day, you're converting kinetic energy into friction/heat and on heavy braking that heat goes into the rotor, pads and caliper. A lighter rotor will cool down quicker, but on extended descents requiring almost continous braking it doesn't get the chance to cool down.

    Its a highly individual thing whether a brake rotor will work for you. The lightweight rotors like the Aries and Hygia work really well for me until I head up into the mountains where they just don't cope well with 700m+ vertical descents and the added weight of a pack.

    I'd expect these new rotors to suffer from the same limitations, but they'll probably be great if ridden without those limits. What will probably suck with them is that the rotor surface will wear unevenly because there is so little metal in the middle of the track. This is my main criticism of the Hygia SLP rotors which otherwise have been great.

  15. #15
    "They Call Me Bone'z"
    Reputation: facelessfools's Avatar
    Join Date
    Aug 2008
    Posts
    1,609
    Cheers, i did the same experiment in high school, i think its common place for any basics physics class.
    RAH!

  16. #16
    mtbr member
    Reputation:
    Join Date
    Mar 2009
    Posts
    282
    Quote Originally Posted by TigWorld View Post
    I've used the Ashima AiRotor, Alligator Aries, Hygia lightweight rotors and now 2012 HSX rotors.

    In the dry, for short braking distances, like your average XC course, they are almost all the same in terms of performance using organic or sintered pads.

    Where you'll notice the difference is:
    - in the wet; and
    - on long descents with lots of hard braking and stretches where the brakes need to be used almost continuously to control speed.

    In both of these circumstances I've found the rotors with less braking surface suffer from reduced braking power.

    The less thermal mass in the rotor, the quicker you can feel it heat up and start to fade. At the end of the day, you're converting kinetic energy into friction/heat and on heavy braking that heat goes into the rotor, pads and caliper. A lighter rotor will cool down quicker, but on extended descents requiring almost continous braking it doesn't get the chance to cool down.

    Its a highly individual thing whether a brake rotor will work for you. The lightweight rotors like the Aries and Hygia work really well for me until I head up into the mountains where they just don't cope well with 700m+ vertical descents and the added weight of a pack.

    I'd expect these new rotors to suffer from the same limitations, but they'll probably be great if ridden without those limits. What will probably suck with them is that the rotor surface will wear unevenly because there is so little metal in the middle of the track. This is my main criticism of the Hygia SLP rotors which otherwise have been great.
    Surprised your experiment was so neutral. I ran aires rotors for a bit, and they were much weaker than the g3 cleansweep rotors they replaced. I made sure to wear them in well past the TiN coating. Finally gave up on them and went to ashima rotors, which were very close in power to the g3s.

  17. #17
    manufacturer
    Reputation: tehan's Avatar
    Join Date
    Jan 2007
    Posts
    470
    I don't want to quote such long posts, so:

    you guys are not taking in consideration few things. Law of phisics are right and Cheers described them correctly. But,
    When pad material is overheated it will perform completly different to it's original design and this is quicker to acheive with certain rotor designs.
    Second thing is that surfaces with certain design will wear in certain way. This leads to not having force applied from piston distributed uniformly. (pad will start working from an angle, or it will start to cone)
    All is fine in theory but if you start making your own rotors you will find quite quickly that there is more problems with such "light" designs as you think.

    I have already went this way and made some prototypes. First ones were terrible as rotor was eaten by pads quite quick, second was coned, few had overheated spots on circumference of braking track, one had terrible harmonic, etc (i took me months to get it right). So from my expirience it does matter how much material is on braking surfece (these with too less were not working at all) and how the design looks like from circumference perspective of contact between pad and rotor.

    You will probably disagree with me again, but as i said first do your own rotors and you will find how other factors play big role into equation.
    Last edited by tehan; 11-27-2011 at 09:38 AM.

  18. #18
    mtbr member
    Reputation:
    Join Date
    Feb 2007
    Posts
    2,327
    Quote Originally Posted by tehan View Post
    you guys are not taking in consideration few things. Law of phisics are right and Cheers described them correctly. But,
    When pad material is overheated it will perform completly different to it's original design and this is quicker to acheive with certain rotor designs.
    There is an automatic assumption that because this rotor has incrementally less material that it will overheat. No consideration is given to how significant the difference is.

    Quote Originally Posted by tehan View Post
    All is fine in theory but if you start making your own rotors you will find quite quickly that there is more problems with such "light" designs as you think.
    ... as i said first do your own rotors and you will find how other factors play big role into equation.
    The industry is filled with examples of businesses who make things that suck so there's no assumed level of expertise.

  19. #19
    mtbr member
    Reputation: bikerboyj17's Avatar
    Join Date
    Dec 2007
    Posts
    454
    Quote Originally Posted by Cheers! View Post
    I used the Ashima AiRotor for many years. Works great. No issues at all. I still use two sets on a regular basis. 160mm and 140mm for both bikes. One with sintered metal pads, the other with organics.

    I'm very happy. All steel rotors perform the same in braking power.

    No different in power than Hope floatings.

    Braking power is not a function of its surface area. It is dependent on the rotor size and the pad material unless the rotor and pad overheats, which seldom do.

    How have the Ashima AiRotor's been with the organic pads? I thought that they were not reccommended to be used with organic pads because they chew them to pieces.

    The reason I ask is because I have some of the new XTR Race disc brakes on order and they come with organic pads. I already have Ashima AiRotors and would like to use them with the XTR brakes without changing pads if possible.

    Thanks.

  20. #20
    mtbr member
    Reputation:
    Join Date
    Feb 2010
    Posts
    1,475
    Quote Originally Posted by craigsj View Post
    ...No consideration is given to how significant the difference is...
    The difference may not be much, the problem is once you overheat the rotor, braking performance is dramatically less until you can stop braking and let the rotor cool. All you can do is try these rotors and see if they work for your weight, speed and terrain.

    For XC you will seldom have to brake for long enough to overheat any rotor (unless you're being held up by slower riders and having to drag the brakes), but once you hit the big mountains with long descents with a pack etc. you may be wishing for a 20g heavier rotor that doesn't reach its overheat point quite so quickly.

    I've also experienced all of those things Tehan mentioned. The Ashima AiRotors have a tendancy to pulse - particular on the front. There is something in their design that results in harmonic frequencies building up and causing that vibration. The Alligator Aries rotors have a tendancy to rip chunks out of the middle of brake pads. The Hygia SLP rotors wear quickly in the middle of the braking track and you get "coned" pads.

  21. #21
    mtbr member
    Reputation:
    Join Date
    Feb 2007
    Posts
    2,327
    Quote Originally Posted by TigWorld View Post
    The difference may not be much, the problem is once you overheat the rotor, braking performance is dramatically less until you can stop braking and let the rotor cool.
    If the difference isn't much, then the problem you describe is equally a problem for other rotors. There is no problem unless the alternatives are already failing in which case you should be solving that rather than looking for weight savings.

    Quote Originally Posted by TigWorld View Post
    All you can do is try these rotors and see if they work for your weight, speed and terrain.
    That's all you can do with any rotor.

    Quote Originally Posted by TigWorld View Post
    For XC you will seldom have to brake for long enough to overheat any rotor (unless you're being held up by slower riders and having to drag the brakes), but once you hit the big mountains with long descents with a pack etc. you may be wishing for a 20g heavier rotor that doesn't reach its overheat point quite so quickly.
    Riders interested in parts like these are competing on the scales, not the big mountains. Not everyone has access to big mountains.

    "Overheat quite so quickly" again assumes the difference is significant. Just because you imagine a difference doesn't mean it's important. "The difference may not be much" were words you said but apparently don't understand. If you need a DH brake this isn't it. I think everyone understands that already.

  22. #22
    Cannondale Maros Team
    Reputation: vladxc's Avatar
    Join Date
    Jan 2009
    Posts
    258
    Craig, if you were looking at the XCO World Cup, you can spot the current AiRotors at a lot of teams that are not sponsored.
    I am also racing XCO and Marathon races and I didn't had any problems for the past 3 years with the Airotors, if the brakes were properly bleeded.
    This week end even if it was cold, I had the chance to ride the new Ai2 for around 65km and until now are pretty good. I am 70kg and 1.80 tall and I live in an area with a lot of hill and the mountains are pretty close to my house. Maybe you should brake less and let the bike flow?

  23. #23
    mtbr member
    Reputation:
    Join Date
    Feb 2007
    Posts
    2,327
    Quote Originally Posted by vladxc View Post
    Craig, if you were looking at the XCO World Cup, you can spot the current AiRotors at a lot of teams that are not sponsored.
    I am also racing XCO and Marathon races and I didn't had any problems for the past 3 years with the Airotors, if the brakes were properly bleeded.
    This week end even if it was cold, I had the chance to ride the new Ai2 for around 65km and until now are pretty good. I am 70kg and 1.80 tall and I live in an area with a lot of hill and the mountains are pretty close to my house. Maybe you should brake less and let the bike flow?
    I am not arguing against the new rotors, I'm arguing against the armchair engineers that say they will overheat. I have also used Airotors and never overheated one.

    Brakes shed heat into the air; storing it internally in thermal mass isn't a design goal. All we have here are a few people clinging onto some intellectual minutia in order to spread FUD about a part they don't own.

  24. #24
    mtbr member
    Reputation: Batas's Avatar
    Join Date
    Jan 2004
    Posts
    917
    Every brake will overheat. Some faster than others. I didn't try those rotors yet, but from my experience, rotors like those tend to overheat sooner, causing the brakes to fade.

    Recently changed from hope pro rotors to the stock formula on my R1 and the breaking power increased and the fading decreased a bit...

    As I see it, if they fit a persons riding style, they are ok for that person. It doesn't make any sense that you have to change your riding style just to be able to use certain bike part...

    Just my thoughts.

  25. #25
    Grams Light Bikes
    Reputation: pastajet's Avatar
    Join Date
    May 2006
    Posts
    2,275
    Took them out on a couple of forays on really technical terrain, and they felt a lot like the AiRotors. They made the light wispy clicking noise, which is pretty normal on all the cutouts types. They felt strong, and didn't squeal, and didn't fade too much on the long runs I could get them on. It's the winter in Colorado so it's tough to find a really long steep downhill to make extreme fade analysis, but I'll keep testing and see what I can come up with. So far so good!

Page 1 of 5 1 2 3 4 5 LastLast

Similar Threads

  1. Ashima Aro-08 Rotors
    By djonesax in forum Brake Time
    Replies: 1
    Last Post: 07-13-2011, 02:05 PM
  2. Ashima ARO-08 Rotors on Magura Marta SL 2009/10?
    By Copenhagen in forum Brake Time
    Replies: 16
    Last Post: 10-14-2010, 06:52 AM
  3. Origin 8 Ashima Rotors
    By tailwaters in forum Brake Time
    Replies: 0
    Last Post: 07-04-2010, 01:03 PM
  4. ashima rotors with semi-metallic pads?
    By foresterxt in forum Brake Time
    Replies: 1
    Last Post: 04-16-2010, 06:53 PM
  5. Ashima Brake rotors ARO-08 160mm & 140mm
    By Cheers! in forum Weight Weenies
    Replies: 74
    Last Post: 11-03-2008, 08:15 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •