Cracked Deda Newton = suggestions?

Discuss light weight issues concerning road bikes & parts.
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cadence90
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Joined: Sun Dec 14, 2003 1:52 am

by cadence90

nicrump wrote:sorry, pic wont load but looking at your stem from the front its upper left then lower right follow by upper right then lower left.


Thanks Nic, thanks all.
This is turning out to be very informative for me, I appreciate it.
"Gimondi è un eroe umano, che viene sconfitto ma che continua la sua corsa fino a tornare a vincere." - Enrico Ruggeri

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Cyco
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Joined: Sat Nov 30, 2002 4:49 am

by Cyco

And the little 5mm Ti bolts did not inspire confidence. But note that the 3TTT "LESS" stem now replaces the Zepp - it uses 20 mm long 6mm steel bolts at the faceplate in place of the 15mm long by 5mm Ti bolts on the Zepp.


The thread size is markedly more important than thread length. Thread surface area increases as diameter increases, but ~90% of load is in the first 3 threads.
Success is how far you you bounce back up after being knocked down

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cadence90
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Joined: Sun Dec 14, 2003 1:52 am

by cadence90

Interesting sidebar from http://www.cyclingnews.com/teamtech04.php?id=tech/2004/probikes/panaria_battaglin

re: Graeme Browne's bike

"...Inside the "cockpit", it's really no surprise to see Deda's Newton 31.8mm oversize bar and the slightly stronger Deda Magic stem on board. Sprinters need all the stiffness they can get, and with a combined weight of 397 grams, it's one super-stiff, very lightweight combination for the team pursuit world champion...."

Image
"Deda's Magic 31.7 stem - a little heavier than the Deda Newton, but a tad stiffer."

Interesting also that the Magic has the 2-bolt clamp.
"Gimondi è un eroe umano, che viene sconfitto ma che continua la sua corsa fino a tornare a vincere." - Enrico Ruggeri

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Tsielio
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by Tsielio

3bold

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cadence90
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Joined: Sun Dec 14, 2003 1:52 am

by cadence90

Florian wrote:
cadence90 wrote:The stem clamp cracked in 3+ places; I had checked torque but not "torque sequence" :?: Bolts are SRP. Perhaps I overtorqued?

I think it's a clear design flaw:
you can see both cracks starting on the inside of the front plate.
The edges are way too sharp and thin, should be more rounded than they don't start to crack so easily.

Florian is right: I took the stem in to LBS yesterday, and they mentioned that the clamp on the older Deda Newton was a "semi-recall" (i.e. unpublicized) item, because of many similar cracking issues, due to flawed design.
The clamp has apparently been redesigned, and your LBS will replace the clamp for free.
"Gimondi è un eroe umano, che viene sconfitto ma che continua la sua corsa fino a tornare a vincere." - Enrico Ruggeri

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