Ciamillo Gravitas crank, review and poll

Discuss light weight issues concerning road bikes & parts.
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What are the 2 most important things for you on a crank ?

-Design + stiffness
15
9%
-Design + weight
24
15%
-Design + price
8
5%
-Stiffness + weight
70
44%
-Stiffness + price
14
9%
-Weight + price
28
18%
 
Total votes: 159

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ms6073
Posts: 2393
Joined: Fri Jul 23, 2004 8:24 pm
Location: Houston, Texas

by ms6073

So based on the images above, can we conclude that the tubes will be left exposed and there will not be an 'aero' fairing added to the final product?
Michael - The Anaerobic Threshold is neither...

by Weenie


User avatar
djconnel
Posts: 7926
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Location: San Francisco, CA
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by djconnel

ms6073 wrote:So based on the images above, can we conclude that the tubes will be left exposed and there will not be an 'aero' fairing added to the final product?


I think it would be fairly easy to wrap them in shrink-wrap if you want, but that will add mass.
I personally think the aero advantage will be very small: the tubes can draft each other.

User avatar
ms6073
Posts: 2393
Joined: Fri Jul 23, 2004 8:24 pm
Location: Houston, Texas

by ms6073

Somewhat out of left field but it seems to me that with a hollow tube crank arm system like this, seems like a good candidate for using a small low wattage laser and measure deflection of the beam to determine stress variations. While I am in no way remotely knowledgeable as my only exposure to such technology has been piloting aircraft equipped with glass cockpits that employ ring-laser gyros to measure/display pitch, bank, and yaw data on primary flight displays, but seems like when properly calibrated, measurement of the deflection of a laser could be used as a means of provide extremely accurate power measurement?
Michael - The Anaerobic Threshold is neither...

User avatar
carbonLORD
in the industry
Posts: 394
Joined: Fri Jan 23, 2004 6:31 pm
Contact:

by carbonLORD

...I'll play with them shortly. On the http://carbonlord.com/VENGE_.jpg.

Image
carbonLORD.com

ome rodriguez
Posts: 294
Joined: Fri Feb 24, 2006 9:16 am

by ome rodriguez

Just received my combo. Thanks Ted.
Image

revpower
Posts: 14
Joined: Thu Jan 03, 2013 11:31 am

by revpower

wow, looks nice, wonder when i got mine...
Hi ome rodriguez, how long you've been waiting for till you get the combo?

ome rodriguez
Posts: 294
Joined: Fri Feb 24, 2006 9:16 am

by ome rodriguez

Near 4 months.
Here are some pics and weight. Its 110 bcd and 172.5mm. Looks very unique and exotic!
Image
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MichaelB
Posts: 435
Joined: Tue Apr 22, 2008 4:31 am

by MichaelB

I've been following this design for a while, and whilst I wont be able to afford it, I am surprised by the weight.

My BB30 SRAM Red Exogram cranks in 175mm arms (w/out chainrings) are 391g.

So, whilst this design looks cool, is probably stiffer (but there is no confirmation comparison), it's 7g lighter for shorter crankarms, and more than double the price.

So why would you invest in this aside from the look factor ?

User avatar
HammerTime2
Posts: 5428
Joined: Thu May 04, 2006 4:43 pm
Location: Wherever there's a mountain beckoning to be climbed

by HammerTime2

MichaelB,

You appear to not be counting the weight of the BB needed for the SRAM Red Exogram. The spindle is included in the weight of the Ciamillo.

MichaelB
Posts: 435
Joined: Tue Apr 22, 2008 4:31 am

by MichaelB

Hi Hammer,
Nope, that's comparing the same setup shown in the above pic at 384g.

Both arms, spindle and spider

revpower
Posts: 14
Joined: Thu Jan 03, 2013 11:31 am

by revpower

Hi MichaelB, are you sure about it?
Please send the picture about the weight of your sram red exogram.
If it is true, that means that sram red exogram crank is lighter than THM clavicula.
in my opinion it is imposibble.

MichaelB
Posts: 435
Joined: Tue Apr 22, 2008 4:31 am

by MichaelB

Here are my cranks - 175mm, BB30 with std rings (compact)

Image

We know the std rings are 150g for the outer and 33g (Others weights) for the inner. That makes it 346g w/out chainrings, but includes the 5 chainring bolts.

Plenty of pics of cranks on scales here, and weights are consistent.

http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=103730&hilit=praxis+exogram+bb30

All up (w/o BB30 bearings) and with Praxis works chainrings, my crank setup is 491g (391 for crank and 150 for rings).

Yep, it is hard to believe, but there you go !! :up:

kbzoo
Posts: 29
Joined: Mon Oct 11, 2010 3:47 pm

by kbzoo

My Zipp Vuma Quad arms (172.5mm) and spindle weighs in at 388g. I bet some of Zipp's know-how went into the SRAM Red Exogram design as well so not really a surprise with the weight.

MichaelB
Posts: 435
Joined: Tue Apr 22, 2008 4:31 am

by MichaelB

And the added advantage of the exogram cranks is that proprietary chainrings are not requited

by Weenie


thisisatest
Shop Owner
Posts: 1980
Joined: Sat Jun 13, 2009 4:02 am
Location: NoVA/DC

by thisisatest

The vumaquad manufacturing process was extremely labor intensive, the whole layup by hand. It took one person months of training before they were allowed to do the arms, I'm pretty sure they didn't have more than two people at a time laying them up. Two people could lay up either 7 arms or 7 cranksets in one day, I can't remember which, but either one is a mighty small number when compared to how many Red cranks are likely to be made each day...
...aaand, it looks like I went off topic again. Sorry.

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