Ciamillo Carbon-Alloy Gravitas Crankset Photos, Pricing Surface

Wow, those are awesome.

I’m asking the same question as micheal. I want numbers!

can’t wait to fly past a pair of these on fredrick’s bike with my sram force bb30 crank. my crank can beat up that crank.

Exciting news for big-guys. Talked to Ted, and he can make these in any length, including >185mm!

This is a nice alternative to the heavy and boring Zinn cranks, which are the main option out there now.

very cool and futuristic looking……my guess is that the pictures you see above are about as close as anyone will get to them……I dont understand what is wrong the stuff that is from two big S’s…..that stuff clearly hits the mark, seems readily available just about anywhere, cost/weight/performance etc….seem to be very much dialed in…. i know this comment will probably open up a can of spewing dislike for the big corporate players—this should be interesting…..

While I’m not personally interested in the crank as a future purchase, I do think its a interesting concept, and it looks cool.

from an engineering point of view=fail. can’t see this crank design being stiff enough for anybody over 80lbs.

Very pretty looking for one of Fairwheel bikes’ show specials but way too many potential points of failure for my taste compared to a forged crank or even a conventional molded carbon crank.

@B. Well said. unless you had far more info than is available in a picture you can’t offer much more than thumb nail analysis and nothing at all on strength, stiffness.

That said , there’ve been some valid points made r/e number of bonded parts departure from simplicity of forged or carbon.
and departure of money, relative worth.

@B @Kark, some of the claimed engineers around here scare me….

@dwiz
“…their stuff is R&D’d to the max”

Not necessarily. Some top-products, sure, but those large companies also have a lot of inertia, large advertisement budgets, and frequently are spending a good chunk of R&D trying to figure out how to make things cheaply.

There will always be a place for small independent fabricators, as they can pour new-ideas and love of the sport into a product.

@Segg, yes, they will have terrible torsional stiffness.

For those people that complain about the armchair engineers and are asking for an analysis to prove points made in comments – you do not need an analysis to to see if a general concept is good or bad. In this case, the laws of physics dictate that that structure is not a good structure to resist torsional loads applied by the pedas or lateral bending loads applied by the pedals. Not much else to say here.

They look like they are SUPPOSED to flex.

THEY WILL FLEX UNDER THE MASSIVE WATTAGE PRODUCED BY MY CAT 4 LEGS!!!!!!!

GREAT LOOKING. YOU KNOW WHAT ELSE WOULD BE GREAT? IF CIAMILLO HAD DECENT, JUST DECENT CUSTOMER SERVICE . UNFORTUNATELY THE CUSTOMER SERVICE IS POOR AND THEREFORE A RISKY INVESTMENT TO MAKE FROM A COMPANY THAT SIMPLY DOES NOT STAND BEHIND THEIR PRODUCTS.

@B & co: For an engineer it is quite easy to judge this crank as structural nonsense, that’s what engineering is all about … for example: torsional stiffness is best achieved by using large closed sections (http://www.ecs.umass.edu/mie/labs/mda/dlib/ref/section_t.html)
It may be possible to get it to work anyway, but it’s not a “good design” (meaning the stiffness to weight ratio will be poor).

Nobody is putting down equations because nobody wants to teach you idiots mechanics. Anybody with any knowledge of structures would see that those cranks are structurally inefficient.

See:

http://en.wikipedia.org/wiki/Torsion_constant

Torsional rigidity increases with the 4th power of the diameter. The only way for this to be superior is if those carbon tubes somehow have physical properties astronomically greater than those of a molded crank arm.

This is a lazy way of slapping on carbon carbon’s sake.

The weight weenies are going crazy for this crank, but they are going to be sorely disappointed. This thing will be a flexible flier, and I bet it will not stand up to long term use, or crashes.

At my count there are ten instances of the word ‘torsion’ in these comments. Is torsional stiffness that big of a deal? The torsional moment on the crank arm isn’t all that great (around 40 Nm for a 100Kg guy standing on one pedal with the crank arm fixed parallel to the ground). As for lateral stiffness, the same moment applies to bending stiffness (assuming you pedal straight down), so the only place we need a huge amount of stiffness is about the axis of the spindle where we have at least 50 mm wide crank arms to deal with the bending (i’d calculate the centroidal moment of inertia but my solids book is 600 miles away, I don’t know the dimensions of the carbon tubes, and i’m lazy).

Now they can make suspension cranks, all they have to do is put three little shocks in the tubes on each side. Remember to pedal circles, not squares, and you should be golden.

Hmm, lots of mixed comments. It’s certainly an interesting product and those that have followed this brand have certainly witnessed a fair share of developments along the way. I have had positive experiences with the Zero Gravity brakes and can see where a product like this would compliment the set. From what I know of the product there are sets being tested in the real world now and any refinements should be about finalized before orders ship out for 2013. I think it is irresponsible to make assessments from an engineering standpoint without having even handled the product in person. I do realize that experiences with the brakes are hit and miss for some. Consider that the company consists of a small team and most communication is done directly with the owner/engineer. I look forward to giving one a go as soon as I read more about them beyond the photo shoot. I for one appreciate the efforts of a smaller US based company and I think they’ve been in business long enough to have gained my trust in the long run, but to each his/her own.

@royalewihtcheese, torsional stiffness is a big deal with cranks if you’ve ever ridden cranks with poor torsional stiffness. The pedals feel like they are sagging away under your feet and cause a very funny feeling pedal stroke when power hard especially when standing.

Generally, a structure with poor torsional stiffness will have poor bending stiffness in at least one direction as well. These cranks will have poor bending stiffness in the lateral directly which also feels awful when hammering on the pedals and rocking the bike.

Bog, how do you know what these cranks torsional stiffness is?

CJ, do you really think people want to commit to years of education, refinement, dedication to their trade and R&D so you can break their hard earned work in 3 rides? Really? You think Ciamillo wants to be known for making products that fail after three of your CAT 4 group rides? OK… let me know when you break.. I mean buy… a set.

well boutique item it is , that’s all, the eecranks at the very least try to address the big chainring issue by having 170 BCD. But for most of us, we really are not out doing any of the mainstream market product. Even the humble Shimano Sora is more than a match for most what we can throw against it. And if I ned the absolute stiffness, I wouldn’t be doing the crank this way, that’s speaking from a personal background in engineering

pay attention this time you silly wanna be engineering children, carbon/epoxy composites are anisotropic. you cannot judge the properties of the part just by the shape.