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Carbon Rims Can Actually Be Quite Durable
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Stumbled on this on YouTube. Things get really interesting starting around 2:40. Not April Fools btw.

Last edited by: GreenPlease: Apr 1, 19 7:14
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Re: Carbon Rims Can Actually Be Quite Durable [GreenPlease] [ In reply to ]
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Let’s see somebody try this with some Zipps or HED’s.........
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Re: Carbon Rims Can Actually Be Quite Durable [CG99] [ In reply to ]
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How about a Colnago and Visions:

https://www.youtube.com/watch?v=HhabgvIIXik
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Re: Carbon Rims Can Actually Be Quite Durable [CG99] [ In reply to ]
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Hopefully Josh@Silca will see this and chime in but I think you'd be surprised as to how durable the 303 is. Years ago Bontrager posted a video of the destructive testing of their OCLV rims which was really really impressive (I can no longer find said video). Basically they ran raw rims on an irregular roller for time. A typical aluminum rim lasted about a minute. The OCLV rims lasted hours.
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Re: Carbon Rims Can Actually Be Quite Durable [GreenPlease] [ In reply to ]
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I wasn’t aware there was a concern about durability; that has never been my concern. Braking (coupled with price) are the two reasons I stay away, assuming we are talking about rim brakes.
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Re: Carbon Rims Can Actually Be Quite Durable [GreenPlease] [ In reply to ]
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I'd say old news.. at least in regards to carbon clinchers.. Santa Cruz did this video over a year ago when they broke ties with ENVE and did their own rims. The need was to show the world that their Chinese sourced rim was 'better' than the ENVE rim they were replacing at roughly the same price. Not saying that anything in the video is misleading or knocking Santa Cruz in any way... carbon rims do this stuff all the time, but just wanting to note that this is a highly produced, highly choreographed and very expensive video trying to prove a very specific point about a particular company's product... so grain of salt should be taken.

Having said all that, a good carbon clincher rim will handle 2-3x the impact of a heavier aluminum rim any day and 3-5x the impact energy of an aluminum rim of similar weight.. it's been that way for a long time, but that is starting to change as rim makers begin to walk away from ETRTO and other standards.

When we developed Firecrest, we followed ETRTO, so by definition we ended up with about 2.5-3mm thick carbon hooks on the rim. In testing we routinely saw 3-6x impact energy improvements regardless of impact anvil shape (sharp/round/flat) which makes sense as we had simply replaced aluminum nearly 1:1 with a much stronger material. Nowadays, as hooks are disappearing and companies are back fighting for every last bit of weight and NOT following ETRTO, the carbon rims will likely have somewhat less advantage.

Yes, the old video of the OCLV rims being tested were rims we made for Trek which used some very special resins and had some of the greatest impact strength ever recorded for any type of rim up to that time period.

http://www.SILCA.cc
Check out my podcast, inside stories from more than 20 years of product and tech innovation from inside the Pro Peloton and Pro Triathlon worlds!
http://www.marginalgainspodcast.cc
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Re: Carbon Rims Can Actually Be Quite Durable [DFW_Tri] [ In reply to ]
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DFW_Tri wrote:
I wasn’t aware there was a concern about durability; that has never been my concern. Braking (coupled with price) are the two reasons I stay away, assuming we are talking about rim brakes.

Same here.

Assuming that the rim is free of significant flaws, the carbon rim should be quite a bit stronger. The major difference is that once you exceed yield, the carbon rim breaks, compared to aluminum which takes a permanent bend, and will absorb a lot more energy before it goes to pieces.
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Re: Carbon Rims Can Actually Be Quite Durable [rruff] [ In reply to ]
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rruff wrote:
DFW_Tri wrote:
I wasn’t aware there was a concern about durability; that has never been my concern. Braking (coupled with price) are the two reasons I stay away, assuming we are talking about rim brakes.


Same here.

Assuming that the rim is free of significant flaws, the carbon rim should be quite a bit stronger. The major difference is that once you exceed yield, the carbon rim breaks, compared to aluminum which takes a permanent bend, and will absorb a lot more energy before it goes to pieces.

...and many times (I have done so myself) the yielded portion of an aluminum rim can be "massaged" back into place and the rim is still usable :-)



http://bikeblather.blogspot.com/
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Re: Carbon Rims Can Actually Be Quite Durable [GreenPlease] [ In reply to ]
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This does not align with my experience racing and spectating cx. I don’t believe for a second that the tubular 303 is as durable as what we see in some of the stress tests from enve and Santa Cruz.

I wouldn’t trust a wheel from zipp off road unless someone else was paying for it.
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Re: Carbon Rims Can Actually Be Quite Durable [joshatsilca] [ In reply to ]
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Thanks for chiming in Josh ;)
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Re: Carbon Rims Can Actually Be Quite Durable [commendatore] [ In reply to ]
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Yes, by moving the question to tubulars you are totally reframing the question..
Tubulars exist for low weight... so most carbon tubular rims are more or less equal in fracture energy to each other (disregarding flaws, prior damage, etc..) and have fracture energy on the order of 1.5-2x that of a light aluminum tubular. The difference of course is that most are willing to consider a dented tubular as 'OK' and a cracked carbon tubular 'not OK' when in reality both of them should technically be considered past their useful life

I always thought about this from the perspective of 'what if this were a frame'... people who crash their carbon frames and break them never think, 'if only it were an aluminum frame and it were only dented and misaligned so I could just bang on it with a mallet and make it "fine"' However, this is how people think about carbon rims all the time.

The challenge for manufacturers in the tubular category is that people are buying based almost exclusively on weight so it's a really tight corner that they have to navigate to be light enough to be purchased and then strong enough to withstand some pretty severe hits at really low pressures.

Similarly, I leave in a few days for the Flanders-Roubaix week and we've had a similar struggle with teams over the years.. the aluminum rims would finish the week with dozens of small dents and the teams always want to keep using them.. while the carbon rims finish with dozens of little micro fractures and such and the team wants them replaced immediately. From the riders perspective they don't want to see either one again and if everybody is doing the right thing, they will be on all new stuff next year!

J

http://www.SILCA.cc
Check out my podcast, inside stories from more than 20 years of product and tech innovation from inside the Pro Peloton and Pro Triathlon worlds!
http://www.marginalgainspodcast.cc
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