ultra lightweight Ashima AiNEON two-piece disc brake rotor for road cyclocross and mountain bikesWayne at Ashima is always working on something new and lightweight when it comes to disc brake rotors.

When we saw him at Eurobike, he had some very interesting dual layer designs that incorporated a unique bonding/mating design as well as some fan-cooled rotors for heavy duty applications. While the rapid prototype air cooled systems might still be in the back of his head, the new AiNEON two-piece rotor shown here all but replaces the dual layer carbon-steel-aluminum D-Matrix rotors.

Using an alloy carrier that, yes, uses just half of the standard 6 mounting bolts, he’s claiming a weight of just 72g for the 160, making it one of if not the lightest two-piece rotors on the market when it hits in April. A 180mm will follow at the end of May. Carriers will be available in Red, Blue, Black or Gold.

The stainless steel braking ring appears to have the same pattern as the minimalist design as the Ai2 rotors we’re testing, but Wayne says the higher heat conduction rates of the aluminum carrier improve heat management.

UPDATE: We just got word they are working on a 6-bolt version, too, due to customer demand. Pricing for the 160mm rotors will be US$ 68.00 with 3 titanium bolts and US$ 50.30 with 6 steel bolts.

Despite the bare bones look and weight, they’re claiming usage from XC to AM. Word is there’s a package on the water for us with these new guys, so we’ll put ’em to the test when we get them.

Interested in doing a little comparison? Some other recent lightweight rotors we’ve posted include the Absolute Black and Saris’ coverage of Scrub  at NAHBS.


  1. I can’t wait to see what happens when you come bombing down a mountain on your CX bike dragging these the whole way!

  2. Hooray for sheared disc mounts on hubs. Hub makers better beef up the mounting tabs thereby negating weight savings in the rotor. Brilliant idea.

  3. Being a fairly lightweight rider (143lbs), I really like lightweight rotors because I can almost always get away with using them. However, I just can’t talk myself into only using 3 bolts. Bring ’em out with 6 bolts and I’ll take 2 sets.

  4. As always, loving all the hate. Anybody have a % on how many pros (including downhillers) that run 3 bolts? Anybody remember the old school AMP disc brakes with three rotor bolts?

    That said, I run six anyways.

  5. Do not want. In fact, I’ll ignore everything from Ashima from now on out of principle. It appears they don’t know what they are doing.

  6. Are they really saying these are a valid option for all mountain riding?

    I’d be scared to use them going downhill the highest “mountain” in Florida (Sugarloaf, 312 feet).

  7. But the Hope rotors have less of a force acting upon them (the radius on which the bolts are located is larger than the 6-bolt IS standard) plus i think the bolts themselves are larger. They are made for their own 3-bolt hubs.

  8. i’ve been running 3 bolts on my rear rotors. i use the front brake most of the time anyways. and again, there’s still the front brake if you lose 1 or 2 bolts on the rear wheel. besides, if the installation is done right (thread lockers do a good job of not losing these bolts), 3 bolt rotors are as good as 6 bolt rotors.

  9. Pro downhill guys running 3 bolts are not doing it on weight weenie hubs which is surely where these rotors will end up. Someone call AC and ask them what they think of the idea. I don’t think they make an aluminum reinforcement ring big enough to work with these rotors!

  10. I only pointed out the DH guys to prove that it only takes three bolts to hold a rotor on under extreme use. Lots of XC guys have been doing the same thing on their lightweight hubs for years.

  11. Please bare in mimd that the six bolt disc mounting design was built to handle the largest braking loads that a down hill bike sees using large diameter disc brake rotors. Using a six bolt design is defintley over kill for on a cross country/ marathon bike.

  12. I saw a recent photo of Cedric Gracia’s V-10 from the last WC and he was sporting 4 bolts, instead of 3 (or 6) like in years past. We were discussing that here at the shop and came to the conclusion if you happen to lose one bolt out of a 3 bolt set up you’re pretty much screwed. But if you lose one bolt out of a 4 bolt cluster you should still be fine (in a WC DH format). A number of pro DH’ers around here have been running 3 bolts for years with absolutely no problem-and that’s on 200mm rotors.

  13. “I only pointed out the DH guys to prove that it only takes three bolts to hold a rotor on under extreme use. ”

    And yet AC can’t build hubs that don’t fail even with all 6 bolts unless the rotors are properly reinforced. Sorry, dicky, but your argument doesn’t hold water. Sure people have been omitting bolts for years, but they race on scales.

    The lack of 6 bolts isn’t the only problem with this garbage. When the manufacturer claims improved heat management from the aluminum carrier despite a lack of thermal mass in the carrier and minimal thermal contact with the outer ring, you have to wonder if there’s anyone there that isn’t an engineering hack. This thing is designed to overheat and buckle.

  14. “Anybody have a % on how many pros (including downhillers) that run 3 bolts? ”

    Nobody should care what a pro, who makes a run and thoroughly checks and rebuilds his bike does. This is the most idiotic way to save, what several grams for titanium bolts?

    The proper way to do that is to incorporate the carrier into the hub – like Hope does on some of their wheelsets.

    And it is not the disk that may fail – it is the hub. It is not designed for that.

  15. What about just using 3 of their aluminium rotor bolts, that’s even scarier…

    They’re the same weight as KCNC steel rotors (which come with 6 bolt holes!), don’t get it myself.

  16. ShopMechanic, Glad to see I’m someone’s hero.

    craigsj, So AC hubs suck regardless of the number of bolts used. Good to know.

    Mindless, Checking bolt tightness isn’t gonna stop a hub from failing.

    I don’t care what the pros do either. I run six bolts because there are six holes, and that’s about it. I’ve never had issues with my bolts coming loose once they’ve been torqued properly. Is this really happening to folks USING BOLTS WITH FACTORY THREADLOCK already applied? I know guys who ride in the Pisgah National Forest with regularity on three bolts that don’t get “checked and rebuilt after every run.”

    I’ll still run six and stay away from AC hubs…

  17. wait wait wait.. so you skip 3 of the 6 holes on your hub?? i remember the industy fighting to get away from 3 and 4 bolt hubs/rotors some time back, hopefully we are not looking at a new “standard”

  18. Bunch of children here… look people, 15 to 20 years ago… THREE and FOUR bolt disc rotors were the norm, and things like six bolts were seen as excessive overkill to be reserved for DH riders bombing the kamikaze on bikes using the formula double-rotor marzocchi bombers and such, and even that was rare.
    My Amp D1/Rockshox disc brakes are all three bolt rotors, and they work just fine and I’ve never sheared a bolt or lost a rotor.

What do you think?