# Cannondale Hollowgrams; manufacturing steps



## metoou2 (Mar 18, 2009)

Would like info on the steps Cannondale (Cannondale's vendor) uses to produce the Hollowgram *crank arms*. For this thread, I'm not interested in the other components that make up the Hollowgram cranks.
What I know or at least what I "think I know".
- billet alloy milled out to create (2) clam shell halves per arm
- these clam shells are bonded together using some sort of epoxy resin
- arms are anodized either black or silver

Of most interest, I would like to know if the (2) halves are bonded and *THEN* anodized or..........the (2) halves are anodized and *THEN* bonded together. 
No I'm not launching a crank arm to compete with Cannondale. I'm considering anodizing some black Hollowgrams that have multiple shoe rubs. My searches have turned up numerous cyclists claiming they anodized Hollowgrams with no ill effects on the epoxy resin used by Cannondale. Some claim to have anodized their cranks (3) to (4) years back and they are still going strong.

And yes, I know that Cannondale would NEVER advise the consumer to re-anodize these cranks.
There are industry reps in this Forum. There are Cannondale retailer / distributor types in this Forum. Let me know............I'm not asking for proprietary info. Or am I?


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## fenderfan (Nov 25, 2010)

metoo2 you are quite correct on the manufacturing process. I only know this because I visited the factory and actually saw the process in action. The techs even crosscut a pair of the cranks to expose the hollow innerstructure. The whole process was totally awe-inspiring.

While I am not a mech-e I don't see any major problems with your suggestion however since production has moved to Asia there may have been some spec changes that could affect your decision.


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## metoou2 (Mar 18, 2009)

Thanks for the feedback. In the past few days I have spoken with some chemical plating companies that have real world experience anodizing Hollowgrams sent in by consumers. They stated their processes aren't aggressive enough to destroy the bond.

Also found some chemical eng charts showing resistance levels of epoxy bonds to different chemicals. Chart showed epoxy can survive sulfuric acid (etching process) and epoxy can survive caustic soda (anodizing process). 

You're a 'lucky dog' to have gotten in on that tour. I'm assuming it was a U.S. based company? I knew all frame and fork production went to Asia. Didn't know the Hollowgrams went East as well.
I don't know what all you saw or how your memory serves you but;
were the halves etched, bonded and then anodized or.........
were the halves bonded, etched and then anodized? 
Last, if the crank that you saw cut open was BLACK, was it silver on the inside? 
I'm a Production Mngr with an Ind Eng degree so I really enjoy digging into the manufacturing side of cycling.


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## Dan Gerous (Mar 28, 2005)

The Hollowgrams are still made in Bedford... so are the Leftys.

Back on topic, isn't it a lot of trouble and cost just for the crankarms cosmetics?


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## metoou2 (Mar 18, 2009)

Dan Gerous said:


> The Hollowgrams are still made in Bedford... so are the Leftys.
> 
> Back on topic, isn't it a lot of trouble and cost just for the crankarms cosmetics?


absolutely
My true interest is in manufacturing processes.................and Cannondales.


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## Dan Gerous (Mar 28, 2005)

metoou2 said:


> absolutely
> My true interest is in manufacturing processes.................and Cannondales.


Good reasons then! 

Now, doesn't help for the process order (bonding vs. anodizing) but here's a look before both steps.


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## metoou2 (Mar 18, 2009)

Dan,
those pics only fuel my jealousy!!!! I know you're a Canadian with a cool blog that gives out good insight into the world that is Cannondale. Jealous or not I'm glad you are willing to share.
I got it! You are a DOREL (Canadian based co.) inside marketing guy tasked with giving us all just enough info to stoke the fire. Good job, it's working!
I have communicated with a transplanted Canadian who now lives in Taiwan. He spoke with his contacts over there, Cannondale product development people. He stated they are definitely bonded and then anodized. He wasn't very detailed in his response.
The only mystery remaining;
excluding the machining phase there are (3) steps involved. bonding / etching / anodizing.
A local metal plating co. I spoke with said the sequence is MOST likely; etch / bond / anodize.
On your next coffee break swing by the eng. dept. there at 'DOREL' and ask around will ya?


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## vanerven (Nov 4, 2008)

Another thing, I hope they will one day produce 177.5 mm (or even 180 mm) cranks, just like Shimano, Sram and Campi.


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## Dan Gerous (Mar 28, 2005)

metoou2 said:


> Dan,
> those pics only fuel my jealousy!!!! I know you're a Canadian with a cool blog that gives out good insight into the world that is Cannondale. Jealous or not I'm glad you are willing to share.
> I got it! You are a DOREL (Canadian based co.) inside marketing guy tasked with giving us all just enough info to stoke the fire. Good job, it's working!
> I have communicated with a transplanted Canadian who now lives in Taiwan. He spoke with his contacts over there, Cannondale product development people. He stated they are definitely bonded and then anodized. He wasn't very detailed in his response.
> ...


I don't work for Dorel, Cannondale or any of their buisness partners (I wish I did though!). Those pictures were taken in an online article/review about the Scapel if I recall.

Edit: found the picture source.


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## metoou2 (Mar 18, 2009)

Thanks for the article link...............
For your next assignment, find a pic of Sagan doing a nose wheelie across the finish line.


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## zamboni (Sep 11, 2003)

No way Cannodale would let the public know the process of mfg this crank, why should they?


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## metoou2 (Mar 18, 2009)

zamboni said:


> No way Cannodale would let the public know the process of mfg this crank, why should they?


The guy answering the tech line in Bedford discussed the process at length with me.
My friend in Taiwan called his buddies working for Cannondale Product development in Taiwan and they freely discussed the process. 
There's nothing proprietary about what they are doing. The processes are all well know and used by many industries. The auto industry has been bonding on door hinges for years.
Cannondale didn't invent bonding metal alloy parts with epoxy resin.

Thank you for your input.


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## Dan Gerous (Mar 28, 2005)

metoou2 said:


> Thanks for the article link...............
> For your next assignment, find a pic of Sagan doing a nose wheelie across the finish line.


That's a tougher one... You mean like this but in an actual race? Maybe from when he was a mountain bike racer...


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## metoou2 (Mar 18, 2009)

Dan,
Good job on the pic! I was just throwin down a challenge to see if you could deliver.
I still enjoy that pic of Sagan riding a wheelie up that insane mtn. stage last year that you posted in your blog.


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## Dan Gerous (Mar 28, 2005)

A no-handed wheelie no less! While climbing the Angrilu! 
There are a lot of fun facts about Peter Sagan. The guy's a phenomenon.


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