The ultra lightweight Ciamillo carbon fiber crankset revised to come in at 390g

Ciamillo showed prototypes back in October, and now they’ve apparently completely changed up the design. Or, at least, the insides.

The originals promised to be under 450 grams. Shown above is the rework, which they say tips the scales at a paltry 390g. Final details are still under wraps (quite possibly because they’re still being finalized), but the customization options remain. You can specify crank length, BCD (110, 130 or 135) and anodization color for the alloy bits.

The carbon tube structure is a vast departure from the very sleek, aero looking originals, but they also drop significant weight. The weight, BTW, is without the bottom bracket/bearings or rings, and is based around a BB30 spindle. Word is it’ll have a carbon fiber cover to hide the rods, but the shape will be more rectangular. More as we get it.

UPDATE: MSRP will be $1,100, but they’re taking pre orders for $700. Ted Ciamillo told us this allows them to get the product in the market earlier for riders willing to provide feedback and essentially act as phase two beta testers. He said they do tons of testing on their own, but they always learn more when more people have been riding them for four or five months. Wanna get in? Email them with your contact info, crank length, BCD and preferred color. You’ll be among the first to ride them, and they warranty anything that doesn’t hold up on these first generation models. Ted’s working on an information page that’ll fill in more of the crank’s tech specs, and we’ll post more as soon as that’s live.

Thanks to Gregory for the tip!


  1. How to show you have no idea of basic construction with carbon?

    And no, this is not a kind of “somebody has to try it to get better stuff”. This is simple physics with the resultic basic rules of construction which can’t be ignored by just one or two prototypes… even if they cost 700 $

  2. wow looks like that “tinkering” they were doing on the last prototype went more than I would have ever expected. It looks interesting, but still pretty rough compared to what we saw in october. Any word on when we can see a more complete picture than a just an unfinished drive side crank arm?

  3. also they have been working on cranks for the past 6 years, is this one actually going to make it to market, or are they going to pull it again at the last and decide not to do it?

  4. No shear connection between the carbon tubes, stress concentrations at the aluminum/carbon joint, probably no galvanic buffer at the bond, some goofy cover plate that creaks (or will so enough), expensive…..

  5. Love to see some actual comparative data on these in terms of stiffness etc… I would be surprised if Rotor hadn’t at least tried this in testing.

  6. Obviously there’s nothing to buffer galvanic reaction between the aluminum and CF……cuz it’s not pointed out with an arrow and isn’t mentioned in the story, even though it’s been standard practice for a long time. It’s truly dumbfounding that no one else pointed that out. No doubt you can tell the assembly will creak later by listening to the picture.

    Alas, there’s little hope for the future given the very weak engineering insight and scientific literacy of many of the commenters.

  7. I’ve been trying to get a hold of these guys for nearly 2 months for a bolt and washer from them for my Zero G CX brakes. 6 emails, 2 voicemails, no response at all. Now their VM box is full, so I can’t even leave a message. I’d be cautious when ordering from Ted and Co.

  8. 390g is only 5g lighter than the cheaper and probably stiffer Lightning cranks.
    There are other cranks out there that are even lighter for the same price as these or cheaper…

  9. carl, you have superb x-ray vision. how you can see the laminate schedule of those tubes is astounding.

    oh, thats right, freshman engineering students haven’t done any fiber science yet have they.

    i think bundled carbon tubes make perfect sense for a light carbon cranks.

  10. Brandon and I must have the same problem. I just gave up and found a part that works at the local hardware store.
    Too bad that such interesting engineering gets washed away by some of the worst customer service I have ever encountered

  11. now I know what to do with the broken carbon flat bars and seat posts…just need to get some Al. billet, set-up the drill press…

  12. @’Steve M’
    The article mentions that the Al bits are available in anodized colors. The anodized surface will provide sufficient protection against galvanic corrosion.

    If the tubes had been specifically optimized for directional forces, I don’t think they would have kept them round in profile. Also, you can see the cut-away of the carbon tubes, and from what I can tell the wall thickness seems consistent. That makes me think the lay-up was not specific to a certain orientation. If it was, you’d need X-Ray vision to correctly assemble the crank. 😉

  13. I assume the third, empty socket would allow you to ‘tune’ the crank for riders who need more stiffness? That would be even more effective if that third, center socket was offset, maybe 5mm(?). Even if the socket was offset at the spider end and in-line at the pedal end (angled tube), they’d achieve much higher stiffness.

    Overall, I kinda like it.

  14. from 1994: my 175 mm 7075-T6 aluminum topline hyper C mtb cranks. 386 grams with bolts and spacers. msrp $179.79 20 years of racing and still going strong……

  15. Wow…. just wow. There are so many reasons this is a terrible design… but I’ll just say that I would never, ever trust my life to these. (And for the record – I’m a mechanical engineer currently in robotics with a background in sports equipment).

  16. @G.. the posters you are commenting on are at least trying to bring some arguments to the discussion.

    The design doesn’t look to be very smart. All basic constructing laws have been neglected. Oh and I am not just an armchair engineer, but an actual engineer with experience is designing and manufacturing of aluminum parts

  17. steve, there is no way you can determine the fiber orientations from a “cut away” view. a .125″ thick laminate can have as many as 50 ply’s(F.A.W. 70) ranging from 0* to 90* and anywhere in between.

    even at like F.A.W. 300 you are looking at a 12 ply stack for .125″ in which all ply could be +/-45 resulting in pure torsion resistance.

  18. p.s, round is the best shape for directional forces in a lever when it come carbon/epoxy composites. the work is done in fiber orientation. you need to bone up on isometrics/an-isometrics.

  19. @me – you may want to revisit your basic statics textbook. Like that part that mentions that the torsional moment of area having that pesky “r” as a 4th order factor. Or that completely wasted material they’re pushing towards the middle of the torsional axis (and, for that matter, the neutral plane of bending) by having two tubes of constant cross section (check the cut ends)?

    Or how about the parallel bars of carbon rather than increasing the d (a second order factor) to support the maximum bending moment at the crank interface?

    And don’t even get me started about the stress risers from the non-filleted bonding regions (right on the region of maximum compression stress, no less). And as I’m sure you know, most of the compression load is supported by the epoxy which is terribly notch sensitive.

    Is it possible to make this design in such a way it doesn’t break? Sure, with enough material. But it’s a terribly optimized system, which means a lot of excess weight – supposedly, the whole point of this design.

    If you want a super-lightweight design, you start by optimizing the shape to reduce stress as far as possible while meeting design constraints (and considering manufacturing processes and peculiarities of your chosen material), then you optimize the layup for that shape – then go back through until you don’t see marked improvement.

    I think the smoking gun here, though, is the clear initial design intent of using a third tube in the middle of the crank (see those two machined pockets doing nothing but adding weight?)- right at the neutral bending axis and torsional axis, where it would do almost NOTHING but increase the lateral rigidity of the crank by ~50%, something that could be much more efficiently done elsewhere.

What do you think?