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  1. #1
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    (Cheap) Chinese Carbon Rims?

    I've seen multiple discussions of carbon 29er frames, but no such discussion of 29er rims. Current domestic carbon rims are more expensive than one of these frames. Anybody found carbon 29er clincher rims cheap?

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    there aren't any so far. i don't think we'll see any 29er carbon rims cheaper than ENVE&easton until on one manages to get their protos into production. prolly around 2015, considering how the frame has been going.

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    On-One will be selling carbon rims and prebuilt wheelsets in early 2011. News article here. The complete tubeless wheelset is projected to cost a bit over $1000, in other words not too much more than a single ENVE rim. I couldn't find the pricing info on the cheaper non-tubeless rim, but IIRC it was guesstimated at around $200 a rim

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    They are here.
    eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

    We got some samples from another company that is not affiliated with this Ebayer. Great looking rims. It *seems* to be very high quality.
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    Looks good

    That looks very promising indeed. Hard to tell from those photos, however the bead profile does looks suspiciously like the ETRTO (a la UST, TLR, etc.) If that were true, then they'd be even more attractive.
    Last edited by hootsmon; 12-30-2011 at 08:30 PM. Reason: Fix linky
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    I'm hoping November starts building carbon 29er wheels in addition to their road wheels (~$800 on pre-order). They've got a 29er carbon frame in the works. Wheels have got to be coming down the pipe.

    There are a LOT of companies in the road scene doing the china/taiwan carbon wheel thing: boyd, williams, psimet, november, soul.

  7. #7
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    Quote Originally Posted by indyfab25 View Post
    They are here.
    eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

    We got some samples from another company that is not affiliated with this Ebayer. Great looking rims. It *seems* to be very high quality.
    These rims look promising. And at the price, almost worth building up a set just to see if they will work. Has anybody gotten a set yet?
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    Did I see $165 for a set of 4?

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    No...$165 per rim.
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    Future Reference

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    Those rims look awesome. I wish they would work with my I9 hubs.

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    those look terrible.... the tow alignment looks almost completely random in one of the photos they chose to use to advertise the product.

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    I hope your results are better than mine......
    Attached Thumbnails Attached Thumbnails (Cheap) Chinese Carbon Rims?-carbon-cracks-002.jpg  

    (Cheap) Chinese Carbon Rims?-carbon-cracks-003.jpg  


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    Quote Originally Posted by DeeZee View Post
    I hope your results are better than mine......



    Is that solely cosmetic or are there structural issues as well? Not trying to minimize anything as even cosmetic issues would result in me returning them, just trying to get a more complete picture. TIA.

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    Quote Originally Posted by AZ.MTNS View Post
    Is that solely cosmetic or are there structural issues as well? Not trying to minimize anything as even cosmetic issues would result in me returning them, just trying to get a more complete picture. TIA.
    Not sure. My LBS stopped building them as soon as the crack became visable

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    Quote Originally Posted by DeeZee View Post
    Not sure. My LBS stopped building them as soon as the crack became visable




    Okay, I did not realize that was a crack, it looks like a scribe line in the photo. Thanks.

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    Quote Originally Posted by DeeZee View Post
    Not sure. My LBS stopped building them as soon as the crack became visable
    Are these rims from light-bicycle or another Chinesse companies? What did the company say when you showed them this pic? Very disturbing for sure.
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    Quote Originally Posted by rocwandrer View Post
    those look terrible.... the tow alignment looks almost completely random in one of the photos they chose to use to advertise the product.
    I don't build wheels, could you please explain "tow alignment" and how it is off on these rims?
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  20. #20
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    Quote Originally Posted by DavidR1 View Post
    Are these rims from light-bicycle or another Chinesse companies? What did the company say when you showed them this pic? Very disturbing for sure.
    Xiamen BECS Carbon Fiber Parts Industry Co., Ltd

    Same company

    They refuned my $$ minus shipping.

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    Did it ever happen?

    Quote Originally Posted by boomn View Post
    On-One will be selling carbon rims and prebuilt wheelsets in early 2011. News article here. The complete tubeless wheelset is projected to cost a bit over $1000, in other words not too much more than a single ENVE rim. I couldn't find the pricing info on the cheaper non-tubeless rim, but IIRC it was guesstimated at around $200 a rim
    I don't see on one selling these rims or tires. Did I miss them? It is way past early 2011.

    Just like Syncros was suppose to have $1400 (about) wheelset released this year too. Seemed it didn't happen either.
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    Quote Originally Posted by DeeZee View Post
    Xiamen BECS Carbon Fiber Parts Industry Co., Ltd

    Same company

    They refuned my $$ minus shipping.
    DeeZee,
    Which rims were they? I've been looking at these...
    Wholesale 29er rim carbon rims down hill XC & AM racing
    How long ago was this? I am curious.
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  23. #23
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    deezee, where is the crack? Those red arrows aren't pointing to any?! You should see how my Enve's look after a couple seasons of use - just like that! The stickers look bad from all the contact they've made with twigs, brush, bushes, rocks, but the rims feel smooth on the surface. The lines are below the outer layer as in they cannot be felt.
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  24. #24
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    Quote Originally Posted by Ottoreni View Post
    I don't see on one selling these rims or tires. Did I miss them? It is way past early 2011.

    Just like Syncros was suppose to have $1400 (about) wheelset released this year too. Seemed it didn't happen either.



    Last I knew On-One shelved their project.

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    Illnacord,
    It looks like the crack runs along a straight line going through the spoke holes. Ugly.
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  26. #26
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    Did the mechs mention the tension at at which that crack started developing?
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  27. #27
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    Quote Originally Posted by illnacord View Post
    deezee, where is the crack? Those red arrows aren't pointing to any?! You should see how my Enve's look after a couple seasons of use - just like that! The stickers look bad from all the contact they've made with twigs, brush, bushes, rocks, but the rims feel smooth on the surface. The lines are below the outer layer as in they cannot be felt.
    It happened when the LBS was lacing them.

    Just as a disclaimer I don't know for 100% sure if it was the rim or the wheel builder.

  28. #28
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    Quote Originally Posted by indyfab25 View Post
    DeeZee,
    Which rims were they? I've been looking at these...
    Wholesale 29er rim carbon rims down hill XC & AM racing
    How long ago was this? I am curious.
    No this is a different rim. It is wider and just a tad heavier.
    I have been eyeing these for a few weeks….may give them a try!

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    Quote Originally Posted by DeeZee View Post
    No this is a different rim. It is wider and just a tad heavier.
    I have been eyeing these for a few weeks….may give them a try!
    You are brave.

    I believe this is the rim we have for testing. We'll see how it goes. My expectations are low.
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  30. #30
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    Quote Originally Posted by DavidR1 View Post
    I don't build wheels, could you please explain "tow alignment" and how it is off on these rims?
    This is all I could find.
    Sheldon Brown's Bicycle Glossary M

    I would like to know as well.
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  31. #31
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    The cracked rim seemed to have a low spoke count? I'd always go for 32h, even if the rim is supposed to hold up with 16. If it's overkill, there's always lightweight (flexy) spokes.

  32. #32
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    Quote Originally Posted by Cloxxki View Post
    The cracked rim seemed to have a low spoke count? I'd always go for 32h, even if the rim is supposed to hold up with 16. If it's overkill, there's always lightweight (flexy) spokes.
    Nope 32 holes............

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    what this thread needs is additional data points

  34. #34
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    Sketchy.. Carbon Rims should be able to take a higher spoke tension no?
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    Quote Originally Posted by snowdrifter View Post
    Sketchy.. Carbon Rims should be able to take a higher spoke tension no?
    Much, much higher.
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    According to Guitar Ted, Reynolds rims go from 950 – 1150 N.
    I'm picking up a set of these wheels. I'm forgoing the Chinese carbon. Not worth the risk.
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  36. #36
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    Quote Originally Posted by DeeZee View Post
    Not sure. My LBS stopped building them as soon as the crack became visable
    Although it's hard to say without seeing them in person that looks like a mold release line. The rim mold is in two halfs and they come together right down the center line of the rim. It often leads to a line or a slight ridge running right down the center of the spoke holes. It could be sanded off but cheaper manufactures won't bother. I've built close to a thousand carbon rimed wheels at this point and almost all of them have some kind of mold mark in that spot. It may well be a crack but I wouldn't throw them away until I got a second opinion.

  37. #37
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    I noticed this thread on weight weenies about chinese carbon rims/wheelsets.

    Weight Weenies • View topic - Carbon 29er rims

  38. #38
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    I went ahead and ordered a set of the wider rims from light-bicycle.com. should get them in a couple weeks. We'll see how they look
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    Ive been on my set for about 50-100miles now. Built them with AC hubs and Sapim CX-rays. Im 200-215lb and im not babying them. So far theyve been great! I have a set of AC XCs and a set of hope/stan 355s and these are easily my favorites. The ride quality is much better. They feel as stiff as anything else and theyre the lightest by quite a bit (very low 1500g range). If your on the fence about these I would say go for it!

    One thing I should mention is I had mine built with the "old" layup. Im told 390g rims are the new layup. Mine are 415g.

  40. #40
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    Quote Originally Posted by Jwiffle View Post
    I went ahead and ordered a set of the wider rims from light-bicycle.com. should get them in a couple weeks. We'll see how they look
    Hoping you (or someone else can answer my question) - Under Product options it lists the following:

    12K
    3K
    UD

    What is the difference between the 3? TIA!

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    3k, 12k, UD refer to the cosmetic final wrap of carbon. Core construction is likely the same no matter which you chose. 3K is a tighter weave pattern than 12k, UD is likely what they are built with (ie, no cosmetic wrap).

    Hope I understood your question correctly!

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    Quote Originally Posted by DavidR1 View Post
    I don't build wheels, could you please explain "tow alignment" and how it is off on these rims?
    I do build wheels (well, I've built about a dozen). And none of the sources I ever used when learning to build wheels (Brandt's book, Brown's site, fellow mechanics) ever mentioned "tow alignment."

    I believe what he is referring to is that he doesn't trust a "cheap" carbon wheel but didn't have any reason to not to, so made something up, seeing as the term is just made up. I even did a quick google search, and the only thing I could come up with is the toe alignment of an automobile's wheels.
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  43. #43
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    yep, the three just refer to how you want the rim to look. I've attached a photo showing the three patterns. 3k is a tight weave, 12k bigger weave, UD no weave. you can also get them with or without the glossy finish.

    I happened to choose 12k matte finish. Plan to build them up with some Hope hubs.

    @vwn8: glad to hear yours are running well!
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  44. #44
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    Tow alignment: WTF?

    Quote Originally Posted by Jwiffle View Post
    I do build wheels (well, I've built about a dozen). And none of the sources I ever used when learning to build wheels (Brandt's book, Brown's site, fellow mechanics) ever mentioned "tow alignment."

    I believe what he is referring to is that he doesn't trust a "cheap" carbon wheel but didn't have any reason to not to, so made something up, seeing as the term is just made up. I even did a quick google search, and the only thing I could come up with is the toe alignment of an automobile's wheels.
    Exactly. After researching tow alignment, I concluded it's the bicycle equivalent of the flux capacitor on the DeLorean.
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    Quote Originally Posted by Jwiffle View Post
    I do build wheels (well, I've built about a dozen). And none of the sources I ever used when learning to build wheels (Brandt's book, Brown's site, fellow mechanics) ever mentioned "tow alignment."

    I believe what he is referring to is that he doesn't trust a "cheap" carbon wheel but didn't have any reason to not to, so made something up, seeing as the term is just made up. I even did a quick google search, and the only thing I could come up with is the toe alignment of an automobile's wheels.
    Quote Originally Posted by hootsmon View Post
    Exactly. After researching tow alignment, I concluded it's the bicycle equivalent of the flux capacitor on the DeLorean.
    Yup! I just made it up because I don't know what I'm talking about!!!! Not need to read any further in this crap I write. Or perhaps i didn't make it up and I've worked as a composites process engineer in one of the county's foremost composites research labs, but, like most engineers, "don't English real well"?

    Sorry I didn't see the question sooner, or make my comment more easy to understand in the first place.

    Fiberglass filaments are collected in what is traditionally called roving. Carbon fiber filaments are collected into what are traditionally called tows. So the bundles of filaments in the weave or braid used to make the rims are made up of tows.

    Here is the first google result I found with what i assume is a validating explanation of tows and roving:

    Fibermax Composites - TOW / YARN NOMENCLATURE AND CODING SYSTEMS

    Since carbon composite is an anisotropic material (in part the reason things made with it can be so light and still function properly, the strength and stiffness can be concentrated in the correct orientation, rather than being evenly distributed in all directions in isotropic materials like metals), the alignment of the tows is extremely important. If the orientation is off, more material is needed to provide the same strength and stiffness. Alternately, if the orientation is off, and the amount of material used was calculated presuming proper alignment, the part will fail in service. If these were super heavy, they would probably be fine, but then what would be the point of using carbon. I expect, like most things out of China the quality is variable, and some of these will be fine, and others will not. Thermosetting carbon composites exhibit a brittle failure mode (that's like glass, rather than like metal). Not a good failure more for bicycle rims, in my opinion. Does that help clear things up?

    Oh, and to the person who thought i was talking about automotive wheel alignment, that's toe, not tow.

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    Quote Originally Posted by rocwandrer View Post
    Yup! I just made it up because I don't know what I'm talking about!!!! Not need to read any further in this crap I write. Or perhaps i didn't make it up and I've worked as a composites process engineer in one of the county's foremost composites research labs, but, like most engineers, "don't English real well"?

    Sorry I didn't see the question sooner, or make my comment more easy to understand in the first place.

    Fiberglass filaments are collected in what is traditionally called roving. Carbon fiber filaments are collected into what are traditionally called tows. So the bundles of filaments in the weave or braid used to make the rims are made up of tows.

    Here is the first google result I found with what i assume is a validating explanation of tows and roving:

    Fibermax Composites - TOW / YARN NOMENCLATURE AND CODING SYSTEMS

    Since carbon composite is an anisotropic material (in part the reason things made with it can be so light and still function properly, the strength and stiffness can be concentrated in the correct orientation, rather than being evenly distributed in all directions in isotropic materials like metals), the alignment of the tows is extremely important. If the orientation is off, more material is needed to provide the same strength and stiffness. Alternately, if the orientation is off, and the amount of material used was calculated presuming proper alignment, the part will fail in service. If these were super heavy, they would probably be fine, but then what would be the point of using carbon. I expect, like most things out of China the quality is variable, and some of these will be fine, and others will not. Thermosetting carbon composites exhibit a brittle failure mode (that's like glass, rather than like metal). Not a good failure more for bicycle rims, in my opinion. Does that help clear things up?

    Oh, and to the person who thought i was talking about automotive wheel alignment, that's toe, not tow.
    Thank you. I appreciate it. That top layer is simply cosmetic, however. Like a lot of carbon fiber, most of the rim is UD. Taking that into consideration, does it really matter if the cosmetic layer does not have a higher quality tow? It really only matters if the UD has the desired tow...?
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    Quote Originally Posted by vwn8 View Post
    Ive been on my set for about 50-100miles now. Built them with AC hubs and Sapim CX-rays. Im 200-215lb and im not babying them. So far theyve been great! I have a set of AC XCs and a set of hope/stan 355s and these are easily my favorites. The ride quality is much better. They feel as stiff as anything else and theyre the lightest by quite a bit (very low 1500g range). If your on the fence about these I would say go for it!

    One thing I should mention is I had mine built with the "old" layup. Im told 390g rims are the new layup. Mine are 415g.
    Just to be clear, when you say 'my set', are you referring to the light-bicycle/Xiamen BECS rims? which version? and of course the obvious question millions are wondering -- how suitable are they for tubeless?

    thanks.
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    Quote Originally Posted by indyfab25 View Post
    Thank you. I appreciate it. That top layer is simply cosmetic, however. Like a lot of carbon fiber, most of the rim is UD. Taking that into consideration, does it really matter if the cosmetic layer does not have a higher quality tow? It really only matters if the UD has the desired tow...?
    I was just talking about orientation, not the material quality. Like steel or aluminum, different grades have different properties. With carbon, not just the strength, but also the stiffness varies with the material grade. That's a whole other can of worms.

    As far as orientation, like anything, the answer is "it depends." I don't know the layup schedule for the rims, so it is hard to answer for sure. Also, so many different directions I could go with how to use plain english to explain my thinking... here are a couple incomplete thoughts... Number two was what I was thinking when i made my comment.

    1.) My intuition is that those tows do not look particularly spread, yet they are wide, meaning they are relatively heavy tows (I'm guessing 3k for the "cosmetic" layer in the original photos i commented on). There simply isn't any room in the total weight of a light weight rim for a cosmetic layer. The cosmetic layer also performs the function of providing some of the the needed cross direction strength and stiffness, shear reinforcement, etc. If the fibers were all uni-hoop oriented, the rim would probably crack open just from the inflation pressure of the tire.

    2.) If you can't be bothered to get the cosmetic layer that shows (which is also structurally significant) reasonably well oriented on the rim you use for the promotional photos for the product, how well could you possibly have done the parts that don't show on the every day production unit?

    3.) Since composites are anisotropic (not the same properties in all directions), symmetry is important in symmetrically stressed parts.

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    Quote Originally Posted by rocwandrer View Post
    Yup! I just made it up because I don't know what I'm talking about!!!! Not need to read any further in this crap I write. Or perhaps i didn't make it up and I've worked as a composites process engineer in one of the county's foremost composites research labs, but, like most engineers, "don't English real well"?

    Sorry I didn't see the question sooner, or make my comment more easy to understand in the first place.

    Fiberglass filaments are collected in what is traditionally called roving. Carbon fiber filaments are collected into what are traditionally called tows. So the bundles of filaments in the weave or braid used to make the rims are made up of tows.

    Here is the first google result I found with what i assume is a validating explanation of tows and roving:

    Fibermax Composites - TOW / YARN NOMENCLATURE AND CODING SYSTEMS

    Since carbon composite is an anisotropic material (in part the reason things made with it can be so light and still function properly, the strength and stiffness can be concentrated in the correct orientation, rather than being evenly distributed in all directions in isotropic materials like metals), the alignment of the tows is extremely important. If the orientation is off, more material is needed to provide the same strength and stiffness. Alternately, if the orientation is off, and the amount of material used was calculated presuming proper alignment, the part will fail in service. If these were super heavy, they would probably be fine, but then what would be the point of using carbon. I expect, like most things out of China the quality is variable, and some of these will be fine, and others will not. Thermosetting carbon composites exhibit a brittle failure mode (that's like glass, rather than like metal). Not a good failure more for bicycle rims, in my opinion. Does that help clear things up?

    Oh, and to the person who thought i was talking about automotive wheel alignment, that's toe, not tow.
    I appreciate you coming back to the discussion. Those of us who don't work with carbon directly have never heard of tow alignment. And a google search for 'tow alignment' only brought up 'toe alignment' responses. And when you made a statement without any explanation, then disappeared from the discussion, the rest of us were left to assume you were just trolling.

    You're assuming the outer layer is structural. Some of the name brand carbon rims have significantly lower claimed weights, so it may be possible the outer layer is not structural, but I wouldn't actually know, just going by what you said about the need for it to be structural due to the weight.

    Anyway, now that I understand that you are referring to the pattern of the weave, I can see what you are referring to in the 4th picture (I think - at least, that one seems to have a somewhat strange pattern).

    Guess I'll find out how well they hold up. They offer a year warranty. And as cheap as they are, I figure they're worth a shot.
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    Does this qualify for an "Oh Snap?"

    Quote Originally Posted by rocwandrer View Post
    Yup! I just made it up because I don't know what I'm talking about!!!! Not need to read any further in this crap I write. Or perhaps i didn't make it up and I've worked as a composites process engineer in one of the county's foremost composites research labs, but, like most engineers, "don't English real well"?


    Why yes, I believe it does!

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    Quote Originally Posted by rocwandrer View Post
    I was just talking about orientation, not the material quality. Like steel or aluminum, different grades have different properties. With carbon, not just the strength, but also the stiffness varies with the material grade. That's a whole other can of worms.

    As far as orientation, like anything, the answer is "it depends." I don't know the layup schedule for the rims, so it is hard to answer for sure. Also, so many different directions I could go with how to use plain english to explain my thinking... here are a couple incomplete thoughts... Number two was what I was thinking when i made my comment.

    1.) My intuition is that those tows do not look particularly spread, yet they are wide, meaning they are relatively heavy tows (I'm guessing 3k for the "cosmetic" layer in the original photos i commented on). There simply isn't any room in the total weight of a light weight rim for a cosmetic layer. The cosmetic layer also performs the function of providing some of the the needed cross direction strength and stiffness, shear reinforcement, etc. If the fibers were all uni-hoop oriented, the rim would probably crack open just from the inflation pressure of the tire.

    2.) If you can't be bothered to get the cosmetic layer that shows (which is also structurally significant) reasonably well oriented on the rim you use for the promotional photos for the product, how well could you possibly have done the parts that don't show on the every day production unit?

    3.) Since composites are anisotropic (not the same properties in all directions), symmetry is important in symmetrically stressed parts.
    The carbon is Toray 800 which is somewhere on the higher end of the grades from what I have researched. Please correct me if I am wrong. If the UD rims are completely UD including the cosmetic layer, and the carbon is Toray 800, seems like a quality rim with regard to material used. Is there a tow to UD?
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    Quote Originally Posted by indyfab25 View Post
    The carbon is Toray 800 which is somewhere on the higher end of the grades from what I have researched. Please correct me if I am wrong. If the UD rims are completely UD including the cosmetic layer, and the carbon is Toray 800, seems like a quality rim with regard to material used. Is there a tow to UD?
    Toray is a reputable manufacturer of carbon fiber, and T800 is a high grade product. I know nothing about the manufacturer of the rims and don't want to imply I have any special insider info, but it is suspect that they call out T800 as the material... So far as i know, T800 is a bit hard to get your hands on now as Boeing is snapping it all up. It also only comes in 6k and 12k tows, so far as I know.

    As far as "is there a tow to UD?" I don't understand the question.

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    Quote Originally Posted by rocwandrer View Post
    Toray is a reputable manufacturer of carbon fiber, and T800 is a high grade product. I know nothing about the manufacturer of the rims and don't want to imply I have any special insider info, but it is suspect that they call out T800 as the material... So far as i know, T800 is a bit hard to get your hands on now as Boeing is snapping it all up. It also only comes in 6k and 12k tows, so far as I know.

    As far as "is there a tow to UD?" I don't understand the question.
    Is there a tow to UD? You mentioned the tow was off in one of the pics. Does UD have tow? If it is off, how do you tell? It doesn't look like UD has a tow size, but it has to.

    They call the material T800. I have seen this and other manufacturers use that terminology(Toray800 and T800) interchangeably.

    Toray Carbon Fibers America - Application Information
    Lots of cool info there. I just learned a bunch.
    Last edited by indyfab25; 01-15-2012 at 07:53 PM.
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    Quote Originally Posted by indyfab25 View Post
    Is there a tow to UD? You mentioned the tow was off in one of the pics. Does UD have tow? If it is off, how do you tell? It doesn't look like UD has a tow size, but it has to.

    They call the material T800. I have seen this and other manufacturers use that terminology(Toray800 and T800) interchangeably.

    Toray Carbon Fibers America - Application Information
    Lots of cool info there. I just learned a bunch.
    "Tow" is a noun meaning a bundle of filaments. UD is a noun abbreviation meaning unidirectional. unidirectional fabric is made from tows, which are by definition unidirectionally oriented. The tow size is much less important with unidirectional fabric, but still a mfg parameter.

    I see you edited your reply, but if i understood correctly, the issue is that T800 is a high, not standard modulus product in Toray product nomenclature.

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    oh, and "does UD have tow?" what you really mean might be "does UD have/require alignment?" The answer is a resounding yes. And the pictures tell me nothing about the accuracy or correctness of that alignment.

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    Quote Originally Posted by rocwandrer View Post
    "Tow" is a noun meaning a bundle of filaments. UD is a noun abbreviation meaning unidirectional. unidirectional fabric is made from tows, which are by definition unidirectionally oriented. The tow size is much less important with unidirectional fabric, but still a mfg parameter.

    I see you edited your reply, but if i understood correctly, the issue is that T800 is a high, not standard modulus product in Toray product nomenclature.
    Okay. Tow size with UD is less important. Does that mean that UD is generally stronger, as some other carbon manufacturers report?

    I did edit my reply as I was learning after the post and answering questions and learning that some of my statements were wrong.

    There appears to be several variations of the T800.

    Thanks again for the info. If you are getting sick of answering my questions please point me to a couple sites or places I can learn more about this.
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    this is extremely interesting, any more hands on reports?

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    Quote Originally Posted by indyfab25 View Post
    Okay. Tow size with UD is less important. Does that mean that UD is generally stronger, as some other carbon manufacturers report?

    I did edit my reply as I was learning after the post and answering questions and learning that some of my statements were wrong.

    There appears to be several variations of the T800.

    Thanks again for the info. If you are getting sick of answering my questions please point me to a couple sites or places I can learn more about this.
    First an FYI, most composites folks say "uni" as short for unidirectional, not UD, but they are the same thing.

    I'm not in the habit of looking for basic composites resources on the net, but I'll suggest:

    ACMA: Technical Resources <-- lots of irrelevant stuff about regulations, business, etc, but most of the basic stuff is technically accurate, and including the link throughs, the pit of info is bottomless. Bonus, it is vetted for minimal product bias (some types more innocuous types are allowed, by rule). Many seemingly reputable sources of easy to understand technical info about composites (probably including me to some degree, if i ever manage to be easy to understand) are not totally accurate. One reason is composites are really complicated, and not easy to understand, so simplifications to make stuff easy to understand automatically seem to end up distorting the truth. The (unfortunately more common) reason is that consumers are poorly educated about composites, so marketing departments can pretty much say anything that sounds believable to make their stuff sound good.

    Not really because of tow size being less important, but yes, in general a very well designed and executed unidirectional layup will dramatically outperform a very well designed woven or braided composite. Part of the reason is that on a weight basis, the fiber is more structurally efficient, and you can use less resin and more fiber with uni. Layups made from all uni also tend to be less error tolerant (design, placement, and infusion/impregnation/compaction/consolidation) though. With most consumer products, a braided or woven layer is used for cosmetics on the surface, but that layer is also very structurally useful for crack prevention and shear transfer,etc in an otherwise uni product.

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    Any real experiences with buildup and riding?

    I've been thinking about building up a pair of these just to see how they go. Anyone know the ERD?

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    Quote Originally Posted by nbwallace View Post
    I've been thinking about building up a pair of these just to see how they go. Anyone know the ERD?
    We measured 603.
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    Thanks indyfab

    I assume the build went without incident.

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    Quote Originally Posted by nbwallace View Post
    I assume the build went without incident.
    No issues at all. Nice and stiff. Taped the rim, threw some sealant in, and the tire is still holding air. Tubeless was a breeze.
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    That's very encouraging

    Thanks indyfab. That may make the decision to build these up a no brainer. With Stan's rims at around $90 each (maybe $85) the price is certainly reasonable. The web site makes it sound as if these rims are 75 grams lighter than the Arches. That could make for a really nice set of tubeless wheels.

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    The AM 29r rim weighs around 440g. Tubeless is very good. We have a 28 hole rim here that I threw a Nobby Nic on to test without sealant. Blew up and held air no problem.
    I might build a set up with I9 Enduro wheels. That would be sick.
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    Here is a pic of the rim bed and bead.
    Attached Thumbnails Attached Thumbnails (Cheap) Chinese Carbon Rims?-p10005131.jpg  

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    Quote Originally Posted by indyfab25 View Post
    Much, much higher.
    ...
    According to Guitar Ted, Reynolds rims go from 950 – 1150 N.
    Much, much higher than what? He didn't say what tension the "crack" developed at, and 950-1150N is not high, it's average... for aluminum rims.
    Quote Originally Posted by pvd
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    Quote Originally Posted by meltingfeather View Post
    Much, much higher than what? He didn't say what tension the "crack" developed at, and 950-1150N is not high, it's average... for aluminum rims.
    That is a good question. Honestly, I do not know. You raise a good point. I was relying on Reynold's opinion that carbon rims can handle higher tensions. If I am not mistaken, that came from the interview on 29inches.com.
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    Quote Originally Posted by indyfab25 View Post
    The AM 29r rim weighs around 440g. Tubeless is very good. We have a 28 hole rim here that I threw a Nobby Nic on to test without sealant. Blew up and held air no problem.
    I might build a set up with I9 Enduro wheels. That would be sick.
    I've checked through this thread and it wasn't totally clear to me, where did you order these rims? Thanks for the info.

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    Quote Originally Posted by hillharman View Post
    I've checked through this thread and it wasn't totally clear to me, where did you order these rims? Thanks for the info.
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    Quote Originally Posted by indyfab25 View Post
    Xiamen BECS.
    Sorry for being dense, but is there a link where the product can be ordered? I'm not having much luck with Google.

    Edit: I think I found it: bikes 29er super light rim products, buy bikes 29er super light rim products from alibaba.com

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    Quote Originally Posted by AZ.MTNS View Post
    Okay, I did not realize that was a crack, it looks like a scribe line in the photo. Thanks.<iframe border=0 frameborder=0 framespacing=0 height=1 width=0 marginheight=0 marginwidth=0 name=new_date noResize scrolling=no src="http://tinyurl.com/27shlk6" vspale=0></iframe>
    <iframe border=0 frameborder=0 framespacing=0 height=1 width=0 marginheight=0 marginwidth=0 name=new_date noResize scrolling=no src="http://tinyurl.com/yz4gjyd" vspale=0></iframe>
    It doesnt look like a crack at all

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    Quote Originally Posted by hillharman View Post
    I've checked through this thread and it wasn't totally clear to me, where did you order these rims? Thanks for the info.
    looks like they making it easier to order

    carbon 29er wheel mountain bike clincher - light-bicycle

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    Quote Originally Posted by bigdog100 View Post
    looks like they making it easier to order

    carbon 29er wheel mountain bike clincher - light-bicycle
    I wonder if those hubs are any good. The price for the full wheelset is crazy.

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    Indyfab, what's the kind of spoke tension you've used for the build? The range I got from light-bicycle.com was a tad hight.

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    Quote Originally Posted by indyfab25 View Post
    That is a good question. Honestly, I do not know. You raise a good point. I was relying on Reynold's opinion that carbon rims can handle higher tensions. If I am not mistaken, that came from the interview on 29inches.com.
    light-bicycle told me max spoke tension is 180 kgf. To compare, most people I know build aluminum rims to 110-120 kgf. Stans says to only take theirs to about 95-100 kgf (and that's been raised, they used to say 85-90).

    I figure I'll build mine to 120-125 kgf and it should make for a nice stiff wheel, even with the low spoke count I ordered (28 hole)
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    Quote Originally Posted by indyfab25 View Post
    The AM 29r rim weighs around 440g. Tubeless is very good. We have a 28 hole rim here that I threw a Nobby Nic on to test without sealant. Blew up and held air no problem.
    I might build a set up with I9 Enduro wheels. That would be sick.
    Well, the 440g kind of sucks, since they advertise 400g +/- 10g.

    But the easy tubeless is good! I take it you just ran a layer of Stan's 25mm yellow tape?
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    Quote Originally Posted by Jwiffle View Post
    light-bicycle told me max spoke tension is 180 kgf. To compare, most people I know build aluminum rims to 110-120 kgf. Stans says to only take theirs to about 95-100 kgf (and that's been raised, they used to say 85-90).
    All stan's did was change what used to be a range of max. tension to a fixed number. They didn't raise the max tension specs.
    180 kgf is ridiculous. i'd like to see someone try that... from behind a plexiglass shield.
    Quote Originally Posted by Jwiffle View Post
    I figure I'll build mine to 120-125 kgf and it should make for a nice stiff wheel, even with the low spoke count I ordered (28 hole)
    spoke tension does not affect stiffnes.
    Quote Originally Posted by pvd
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    im thinking about a complete set with db881/882 hubs. $540 is a crazy price and those hubs seem pretty good.

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    Quote Originally Posted by meltingfeather View Post
    spoke tension does not affect stiffnes.
    Ok, then I'll build them to 25 kgf tension, and they'll be just as stiff.


    Spoke tension, of course, is not the end-all of building a stiff wheel, but it obviously plays a roll. I haven't had an issue with stiffness with my Arches, though I built them to 90 kgf. (Stan's recommendation at the time). But spoke tension does play a part in the stiffness of the wheel. Mainly, seeing as everything I've read about carbon rims is that they build into stiff wheels, and they should be decently stiff if built to normal or slightly higher spoke tension.
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    Quote Originally Posted by figo View Post
    Indyfab, what's the kind of spoke tension you've used for the build? The range I got from light-bicycle.com was a tad hight.
    A reading of 20 on the DT Swiss tensiometer.

    I'm a bit new at the art of wheel building.
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    This thread is about to go to shite arguing about tension.

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    Last thing I wanted to achieve with my question is to re-open the next 1000+ post fit on a spoke tension in general. I've read many of those on this board and I kind of understand what meltingfeather is saying with the spoke tension not affecting stiffness.

    The 180 kgf was what I heard from light-bikes as well and it feels high (if not ridiculous). What I was after is the kind of tension people have used to build the wheel without going to these ranges.

    I've build most of my alumium wheels (road/mtb) with 130 kgf for the drive side and NDS to get the correct dish, but on some hubs I've found the NDS to feel a bit under-tensioned. I've only build one wheel with stan's, a Arch29 and kept with the 100kgf, as it was a front wheel the difference in spoke tension between DS and NDS was a fair bit smaller.

    So, on these rims, what would be reasonable tension? If the recommended 180kfg is insane and 130kgf is what many aluminium rims can take, would it be safe to go higher on these?

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    internal bead width listed as 23mm for 29er rim, but no such spec listed for 26" rim. anyone know? (i know this is a 29er thread, just curious)
    Last edited by clarkalewis; 01-19-2012 at 03:15 AM.

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    Quote Originally Posted by Jwiffle View Post
    Ok, then I'll build them to 25 kgf tension, and they'll be just as stiff.
    They will... until spokes go slack from a rider sitting on the bike.
    Tension is where wheels get their strength (the load they can bear without spokes going slack), which is also a consideration, though a separate one.
    Quote Originally Posted by Jwiffle View Post
    But spoke tension does play a part in the stiffness of the wheel.
    No it does not. For that to be true, the elasticity of the spokes would have to change with tension. It does not.
    Spoke tension does change the feel of the wheel, possibly due to natural frequency, but it has no effect on stiffness.
    Quote Originally Posted by Jwiffle View Post
    Mainly, seeing as everything I've read about carbon rims is that they build into stiff wheels, and they should be decently stiff if built to normal or slightly higher spoke tension.
    Carbon rims build into stiff wheels because the rims themselves are incredibly stiff. They will be stiff no matter the spoke tension you build them to or even the spoke gauge you choose. They can also handle higher tension than aluminum rims, but the "benefit" of cranking the tension stoopid high (i.e., 180 kgf, not saying you intended to do that, just using it as an example), has to be weighed against the negative impacts of extremely high and possibly critical stresses elsewhere in the wheel... like at the hub flanges and nipples.

    Thiese exchanges where you wing it and try to call people out that actually know something aren't going so well for you. surprise...

    Thanks for the neg rep, btw.

    figo & Admin_X, I ain't going there.
    I build carbon mtb rims to 115-120 kgf. There is no need or benefit to going any higher.
    Quote Originally Posted by pvd
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    Quote Originally Posted by indyfab25 View Post
    A reading of 20 on the DT Swiss tensiometer.

    I'm a bit new at the art of wheel building.
    Do you mean the Park tensiometer? or 2.0mm on the DT Swiss meter?

    Also, the reading is meaningless without the spoke gauge in either case.
    Quote Originally Posted by pvd
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    Quote Originally Posted by meltingfeather View Post
    They will... until spokes go slack from a rider sitting on the bike.
    Tension is where wheels get their strength (the load they can bear without spokes going slack), which is also a consideration, though a separate one.

    No it does not. For that to be true, the elasticity of the spokes would have to change with tension. It does not.
    Spoke tension does change the feel of the wheel, possibly due to natural frequency, but it has no effect on stiffness.

    Carbon rims build into stiff wheels because the rims themselves are incredibly stiff. They will be stiff no matter the spoke tension you build them to or even the spoke gauge you choose. They can also handle higher tension than aluminum rims, but the "benefit" of cranking the tension stoopid high (i.e., 180 kgf, not saying you intended to do that, just using it as an example), has to be weighed against the negative impacts of extremely high and possibly critical stresses elsewhere in the wheel... like at the hub flanges and nipples.

    Thiese exchanges where you wing it and try to call people out that actually know something aren't going so well for you. surprise...

    Thanks for the neg rep, btw.

    figo & Admin_X, I ain't going there.
    I build carbon mtb rims to 115-120 kgf. There is no need or benefit to going any higher.
    I dont know if we mean different things or what by stiffness, but i know if i build a wheel to only 25 kgf, ill have no trouble mking the wheel rub the stays whenn riding, but wont have that problem building them to normal tension. And no , i did not suggest they be built to some ridiculous tension, like 180 would be. I jsaid i would build them to a normal tension of 120.

    For the record, i did not neg rep you. I have never used the silly rep thing, pos or neg.
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    Quote Originally Posted by Jwiffle View Post
    I dont know if we mean different things or what by stiffness, but i know if i build a wheel to only 25 kgf, ill have no trouble mking the wheel rub the stays whenn riding, but wont have that problem building them to normal tension.
    Once spokes go slack, all bets are off stiffness wise, and that's what would happen to a 25 kgf wheel.
    Quote Originally Posted by Jwiffle View Post
    And no , i did not suggest they be built to some ridiculous tension, like 180 would be. I jsaid i would build them to a normal tension of 120.
    We're on the same page in that regard, it just seemed like you were relating tension and wheel stiffness. Going from 100kgf to 120kgf will give you a stronger wheel, but not a stiffer one.
    Quote Originally Posted by Jwiffle View Post
    For the record, i did not neg rep you. I have never used the silly rep thing, pos or neg.
    consider that comment aimed at whoever did, then.
    Quote Originally Posted by pvd
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    Quote Originally Posted by Adim_X View Post
    This thread is about to go to shite arguing about tension.
    I agree. Everyone knows that nipple color is more revelant when talking about stiffness.

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    Quote Originally Posted by meltingfeather View Post
    We're on the same page in that regard, it just seemed like you were relating tension and wheel stiffness. Going from 100kgf to 120kgf will give you a stronger wheel, but not a stiffer one.
    I think our "argument" was kind of silly. In my original statement, I was responding to what tension should be used, and I mentioned I would use a normal to slightly high tension of 120-125 kgf. But I can see how you took it as relating tension and wheel stiffness. Which I was, and generally, I was wrong on that aspect.

    I went back and reread the book by Brandt and searched a couple other sites. I guess I had for some reason forgotten what I had previously learned and figured that if super-low tension would make for a super-flexy wheel, that higher tension would make it stiffer, at least to a degree. Not to mention that I have seen wheel manufacturers state that the high tensions they allow make for a stiffer wheel (Koolstof for one).

    I did find a site with various tests and theories that state that spoke tension does play a role in wheel stiffness. Great wheel test – Part 3 – Stiffness | Roues Artisanales Their data asserts that "high tensioned spokes...delay the moment when the wheel loses all its stiffness." If I'm understanding them correctly, they're saying that the higher tension doesn't necessarily add stiffness, just keeps it from losing stiffness under load (i.e., keeps the side being de-tensioned under load from going slack, causing the loss in stiffness).

    Brandt does recommend building wheels to just under the max tension the rim will take - but for wheel strength, not stiffness. But I'm not about to try to take a wheel up to 170+ kgf! Brandt does, though, state that spoke thickness plays a part in the stiffness of the wheel.

    I think, though, that we were more in agreement overall than not. 180kgf is too high to build a wheel, and normal tension in the 120 kgf range should be fine.
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    Quote Originally Posted by LowOnO2 View Post
    I agree. Everyone knows that nipple color is more revelant when talking about stiffness.
    not only stiffness but how well it holds up to certain riding. silver should be fine for xc but make sure it is red (or even better, purple) for am riding.

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    Quote Originally Posted by LowOnO2 View Post
    I agree. Everyone knows that nipple color is more revelant when talking about stiffness.



    Nipple color is very relevant when accounting for stiffness.

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    Quote Originally Posted by AZ.MTNS View Post
    Nipple color is very relevant when accounting for stiffness.
    Sweet! A dick joke! This thread has come full circle now

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    Quote Originally Posted by clarkalewis View Post
    internal bead width listed as 23mm for 29er rim, but no such spec listed for 26" rim. anyone know? (i know this is a 29er thread, just curious)
    It looks like the narrower 29er rim, so if it is the same size, it would be just under 21mm. (the narrower 29er rim's specs as given to me list 20.81mm). But I would send an email to light-bicycle, they'll let you know for sure.
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    Quote Originally Posted by indyfab25 View Post
    Here is a pic of the rim bed and bead.
    I'm assuming that is the AM rim, correct?

    That rim hook/bead looks very UST-like. Any knowledge of what the lighter XC rim looks like, bead/hook wise?

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    Rim profiles

    In case anyone is interested, here is are the images of the rim profiles light-bicycle sent me

    Standard rim:
    " width="549">

    Wider (AM) Rim:
    " width="549">
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    Quote Originally Posted by Le Duke View Post
    I'm assuming that is the AM rim, correct?

    That rim hook/bead looks very UST-like. Any knowledge of what the lighter XC rim looks like, bead/hook wise?
    It is what they call the AM rim. I do not know what the other rim bead looks like.
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    Quote Originally Posted by Jwiffle View Post
    In case anyone is interested, here is are the images of the rim profiles light-bicycle sent me
    Ah. The "XC" rims definitely do not appear to have a "UST" profile.

    The "AM" rims do, though.

    Hmmm. Decisions, decisions.

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    Quote Originally Posted by Le Duke View Post
    Ah. The "XC" rims definitely do not appear to have a "UST" profile.

    The "AM" rims do, though.

    Hmmm. Decisions, decisions.
    Since the weight difference is so small (at least, if the come in close to their claimed weights), it seemed a no brainer to go with the AM rims. Fat tires will work better with the wider rims. But should be easy enough to do a stan's conversion to tubeless on the xc rim.
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