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Thread: Berd spokes.

  1. #101
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    Quote Originally Posted by MikeDee View Post
    Because steel spokes are much stiffer than the Berd spokes are.
    Trolling?

  2. #102
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    Quote Originally Posted by Shark View Post
    Trolling?
    No, just trying to understand what's going on. On one hand, people want more stiffness and stiff wheels equate to more control (they say), then you have these Berd spokes at the other end of the spectrum.

  3. #103
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    Quote Originally Posted by MikeDee View Post
    No, just trying to understand what's going on. On one hand, people want more stiffness and stiff wheels equate to more control (they say), then you have these Berd spokes at the other end of the spectrum.
    Please tell me why you think Berd spokes would build a less stiff wheel than steel spokes.


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  4. #104
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    Quote Originally Posted by Le Duke View Post
    Please tell me why you think Berd spokes would build a less stiff wheel than steel spokes.


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    it's been proven that with steel spokes, gauge has a big factor on stiffness. that due to the stiffness of a single spoke itself. since these berds are floppy fabric, they equate to the stiffness of the thinnest possible steel spoke.

    from the paragraph below you can assume thin spoke equals a flexy spoke, and if a thin spoke can increase deflection 11% vs a fatter one, then it is not to big a jump to assume a berd spoke as strong in tension as possible, will allow more lateral deflection than steel (or any stiffer spoke)

    How does spoke gauge affect stiffness?
    Thicker spokes make a wheel stiffer, if all else is equal. A typical 32-spoke wheel built with 2.0mm spokes is about 11% stiffer than a similar wheel built with 2.0-1.45mm swaged spokes.

    Compare the deflection of two wheels: numbers 39 and 47. Wheel 39 is built with 2.0 1.45mm swaged spokes, but wheel 47 is built with 2.0mm straight-gauge spokes. Hub dimensions are effectively identical, spoke count is the same and the rims are the same make and model, so the only structural difference is the spoke gauge.

    Result? The wheel with thinner spokes deflected 0.051" (1.30mm) in font and 0.067" (1.70mm) in the rear, but the wheel with thicker spokes deflected less: only 0.046" (1.17mm) and 0.055" (1.40mm) for front and rear, respectively. That's an 11% increase in stiffness for the thicker-spoked wheels.

    Interestingly, wheel stiffness depends on more than just spoke thickness: the rim and other factors also contribute, so only part of the increase in raw spoke stiffness shows up in measured wheel stiffness. The thicker spoke by itself is nearly twice as stiff axially as the thinner spoke!>

    from
    https://www.sheldonbrown.com/rinard/wheel_index.html



    Berd wheels will be fine, and strong, and outlast metal by far..... but in a vice and in clamps and doing deflection tests vs metal spokes, berd will deflect a bit more. just push on one berd spoke with your finger then do the same to a metal spoke, which one has more give for equal pressure ? not rocket science. spokes only need to support tension they do not support load. but wheel deflection forces have a better time deflecting a wheel where the load carrying capacity of a spoke is extremely small with berd, vs metal which has 'at least some more' side-load bearing capacity.

    it's not gonna matter for real
    if you want some nice hoops berd is a great option. I been reviewing other industrial uses of PE aramid fibers and the tensile strength and robustness of this stuff is off the charts.

    yes they will get furry after a lot of abuse, still doesn't matter, they'll still outlive your bones. ride in broken glass or bash some rocks of course they may get cut, but metal spokes will nick and eventually break too, so no change there. what does change is these won't break from fatigue -ever- in your lifetime whereas metal spokes eventually will crack somewhere someday.
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  5. #105
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    Quote Originally Posted by MikeDee View Post
    I find this completely amazing. People are talking about how great Boost is, because it stiffened the wheel laterally with just 6 mm of greater hub flange spacing and drove a whole host of other changes to achieve that, and at the other end we have these Berd spokes that make the wheel much less stiff.

    For starters, I don't hear anyone talking about how Boost has changed much other than lightened our collective wallet. It makes a difference on paper, yes, but few can tell much difference on the trail.

    Now if you're talking SuperBoost (aka 150/157) then yeah -- big differences are notable there, and have been for 10+ years or as long as that spacing has existed.

    As for the Berd spokes, I think you're confusing compliance with flex. I don't notice any flex from the wheel, I just note a more muted feel coming through the wheel.

    See?

  6. #106
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    Quote Originally Posted by Le Duke View Post
    Please tell me why you think Berd spokes would build a less stiff wheel than steel spokes.


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    Le Duke has an excellent point here, which is why I only spec my wheels with the finest cooked pasta.

  7. #107
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    Quote Originally Posted by 127.0.0.1 View Post
    those BERD spokes are gonna fray and fail eventually, that is a guarantee

    but I am gonna bet
    you'll die of old age before normal riding will bust one of those.

    barring accidental heat from a 'bike rack in front of an exhaust pipe'
    (likely the biggest real world risk), or
    rock dingers, those BERD spoke will need to physically appear to be furry and
    frayed, and will still hold up. it'll take a lot to make them fail.

    metal spokes will just eventually crack


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  8. #108
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    Quote Originally Posted by mikesee View Post
    Negativity + ignorance is a bad combo.

    bite me. negativity + ignorance is what keeps me atop my milk crate throne behind the 7/11 selling crack to minors.
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  9. #109
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    Berd spokes.

    Id suggest people read up on the properties of Dyneema vs steel and get back to us. Then, think about how that would apply to wheelbuilding.

    Otherwise you are just making unfounded arguments.

    Hint: its 12-15x stronger for the same weight, with comparable resistance to stretch.




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    Yeah, ignorance is really bad. Which is why it's odd that none of the Berd literature lists the actual stiffness of their spokes. I'll assume the "pull strength" is UTS but that doesn't tell us a lot.

    I found a young's modulous of UHMW Polyethylene to be 1 GPa on the Dielectric Corporation's website and up to 100 GPa in the Dyneema literature. The modulous of 18-8 stainless is 200 GPa. So if that's true then a Berd spoke would need double the cross sectional area of a steel spoke to have the same stiffness, everything else being equal, best case.

    Lacking stiffness isn't necessarily a bad thing in use, but the problem is that when designing for fatigue life you want to minimize strain. Berd hasn't released any fatigue data that I can find, and the statement on their website regarding materials and fatigue life is kinda silly. The vast majority of polymers have poor fatigue properties and steel has no fatigue limit if designed properly.

    Dyneema has some handy data, but notice that the steel curve is flattening out, so you can design a bike wheel with steel spokes for infinite fatigue. The Dyneema curve is straight down to 60% as far as I can tell, and they only go to 2 million cycles. So who knows what happens for lower load ranges. On road bike wheels you only need to ride 2800 miles to get to 2 million cycles, but mountain bike's are harsher on wheels.



    http://www.pelicanrope.com/pdfs/Dyne...Tech_Sheet.pdf

  11. #111
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    Berd spokes.

    Quote Originally Posted by Schulze View Post
    Yeah, ignorance is really bad. Which is why it's odd that none of the Berd literature lists the actual stiffness of their spokes. I'll assume the "pull strength" is UTS but that doesn't tell us a lot.

    I found a young's modulous of UHMW Polyethylene to be 1 GPa on the Dielectric Corporation's website and up to 100 GPa in the Dyneema literature. The modulous of 18-8 stainless is 200 GPa. So if that's true then a Berd spoke would need double the cross sectional area of a steel spoke to have the same stiffness, everything else being equal, best case.

    Lacking stiffness isn't necessarily a bad thing in use, but the problem is that when designing for fatigue life you want to minimize strain. Berd hasn't released any fatigue data that I can find, and the statement on their website regarding materials and fatigue life is kinda silly. The vast majority of polymers have poor fatigue properties and steel has no fatigue limit if designed properly.

    Dyneema has some handy data, but notice that the steel curve is flattening out, so you can design a bike wheel with steel spokes for infinite fatigue. The Dyneema curve is straight down to 60% as far as I can tell, and they only go to 2 million cycles. So who knows what happens for lower load ranges. On road bike wheels you only need to ride 2800 miles to get to 2 million cycles, but mountain bike's are harsher on wheels.



    http://www.pelicanrope.com/pdfs/Dyne...Tech_Sheet.pdf
    Bravo!

    These spokes can't be double the thickness of stainless spokes because they work with conventional hubs and wouldn't fit through the spoke holes if they were. They are also a woven material so that their cross sectional area is going to be less than if they were solid like steel spokes are.

    Maybe stiffness doesn't matter much, or maybe it really does. Bike manufacturers are going through all sorts of efforts to stiffen up bikes and forks with oversized tubing, tapered steerer tubes, Boost, etc. and now there's these spokes flying in the face of all that noise.

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    Last edited by MikeDee; 09-17-2018 at 02:02 PM.

  12. #112
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    Quote Originally Posted by 127.0.0.1 View Post
    bite me. negativity + ignorance is what keeps me atop my milk crate throne behind the 7/11 selling crack to minors.

    And then you go throwing in anger and delusions of grandeur and someone might need to take away your myspace account...

  13. #113
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    Quote Originally Posted by MikeDee View Post
    Bravo!

    These spokes can't be double the thickness of stainless spokes because they work with conventional hubs and wouldn't fit through the spoke holes if they were. They are also a woven material so that their cross sectional area is going to be less than if they were solid like steel spokes are.

    Maybe stiffness doesn't matter much, or maybe it really does. Bike manufacturers are going through all sorts of efforts to stiffen up bikes and forks with oversized tubing, tapered steerer tubes, Boost, etc. and now there's these spokes flying in the face of all that noise.

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    Double the thickness?

    No. Just stop.

    The person you quoted wrote "double the cross sectional area", not double the thickness.

    Let's do some simple math.

    A DT Comp is 2.0-1.6-2.0mm. In the middle of the spoke, it's 0.8mm in radius.

    Therefore, its cross sectional area is (0.8^2)*pi. Or 2.0106 square millimeters.

    To DOUBLE the cross sectional area, 2.0106*2= 4.0212.

    4.0212/pi = 1.28. The square root of 1.28 is: 1.13mm. Double that for diameter.

    A 2.26mm Berd spoke would have the same stiffness, per Schulze, as a DT Comp.

    Now, I don't know what hubs you use, but my DT Swiss hubs have a spoke hole of 2.5mm, per their website.

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  14. #114
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    Quote Originally Posted by Le Duke View Post
    Double the thickness?

    No. Just stop.

    The person you quoted wrote "double the cross sectional area", not double the thickness.

    Let's do some simple math.

    A DT Comp is 2.0-1.6-2.0mm. In the middle of the spoke, it's 0.8mm in radius.

    Therefore, its cross sectional area is (0.8^2)*pi. Or 2.0106 square millimeters.

    To DOUBLE the cross sectional area, 2.0106*2= 4.0212.

    4.0212/pi = 1.28. The square root of 1.28 is: 1.13mm. Double that for diameter.

    A 2.26mm Berd spoke would have the same stiffness, per Schulze, as a DT Comp.

    Now, I don't know what hubs you use, but my DT Swiss hubs have a spoke hole of 2.5mm, per their website.

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    The Berd website says "Reduced 1.8mm cross section for improved aerodynamics."

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    Berd spokes.

    Quote Originally Posted by MikeDee View Post
    The Berd website says "Reduced 1.8mm cross section for improved aerodynamics."
    Ok. My math was using the 100 GPa and 200 GPa rating for Dyneema and stainless, respectively. Many Dyneema products are rated in the 130+ range. Which would put the difference at a few percent between the two products. Particularly when, for example, Sapim spokes are made from AISI 302 stainless, which has a YM of 180 GPa.

    Depending on grade of fiber used, they might actually be stiffer than Comps.




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    ...a little knowledge is a dangerous thing...

    ...not sure whether to admire, pity, or laugh at the folks trying to explain the physics and engineering involved here (no...not YOU, or you...you THINK you are doing the explaining but you are the ones that need things explained to you)
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    Quote Originally Posted by IPA Rider View Post
    ...a little knowledge is a dangerous thing...

    ...not sure whether to admire, pity, or laugh at the folks trying to explain the physics and engineering involved here (no...not YOU, or you...you THINK you are doing the explaining but you are the ones that need things explained to you)
    Oh, I readily acknowledge that Im not an engineer. But, Im capable of reading, doing simple math, collecting publicly available data and comparing that to other data.

    If anything Ive said here is wrong, please correct me. Like most other people, Im here to learn.


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    Someone posted that a 1.45 spoke deflects 11% more than a 2.0 spoke.

    ... That's not really that much more, and that's thinner than the thinnest spoke available. There's just not a huge difference to be had in spoke selection, unconditionally I think.

    It's like looking for gold digging in your nose. There's just none there no matter how hard you try. These silly thing are 500 bucks a set! There's not enough potential benefit on the table to make that make sense.
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    Everyone is confusing the two types of stiffness (or bending modes while riding). All the responses above relate to the wheel deflecting in the vertical direction (by a tiny amount compared with tires). This is generally not an issue. The bigger issue with wheels is lateral stiffness and bending. This can be demonstrated by putting the hub in a vice with the wheel horizontal and adding weight to the rims and seeing how far it deflects based on load. Wheels that are "flexy" in this bending mode are harder to steer and can even cause the tire to rub on the chainstays. This deflection is usually MUCH greater then the deflection noted above. Note that this is felt in cornering, particularily if you are heavy and really rail the corners. This is where Carbon really outshines aluminum as most of the deflection is cause by the rim stiffness. As to whether polymer spokes make much of a difference I do not have the data on it but expect it is still more a property of the rim.

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    Quote Originally Posted by One Pivot View Post
    Someone posted that a 1.45 spoke deflects 11% more than a 2.0 spoke.

    ... That's not really that much more, and that's thinner than the thinnest spoke available. There's just not a huge difference to be had in spoke selection, unconditionally I think.

    It's like looking for gold digging in your nose. There's just none there no matter how hard you try. These silly thing are 500 bucks a set! There's not enough potential benefit on the table to make that make sense.
    I think the discussion on these spokes and stiffness of bikes and components in general is useful, as long as we refrain from insulting each other. $500 is not much for a set of wheels. I still believe that they build a less stiff wheel (but perhaps not as much as I initially suspected) and there is the creep problem that I think was discussed in the other thread that would keep me from using them.

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    Quote Originally Posted by MikeDee View Post
    I think the discussion on these spokes and stiffness of bikes and components in general is useful, as long as we refrain from insulting each other. $500 is not much for a set of wheels. I still believe that they build a less stiff wheel (but perhaps not as much as I initially suspected) and there is the creep problem that I think was discussed in the other thread that would keep me from using them.

    There really isn't evidence of creep as yet, although I'll readily admit that it's still early days to make that call. I'm coming up on 10 months and ~2000 miles on my first set, and about to build myself another set for fatbike use.

    If your concern about creep is that the wheels will need to be retensioned, it's probably worth noting here that this happens to some extent with normal steel spokes too.

  22. #122
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    Quote Originally Posted by MikeDee View Post
    I think the discussion on these spokes and stiffness of bikes and components in general is useful, as long as we refrain from insulting each other. $500 is not much for a set of wheels. I still believe that they build a less stiff wheel (but perhaps not as much as I initially suspected) and there is the creep problem that I think was discussed in the other thread that would keep me from using them.
    You really dont think a ~$450 upcharge for spokes alone is a big deal? Maybe we're in different income brackets. Thats a ton for me.
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  23. #123
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    Quote Originally Posted by One Pivot View Post
    You really dont think a ~$450 upcharge for spokes alone is a big deal? Maybe we're in different income brackets. Thats a ton for me.

    It's a lot of money for me, too.

    But everything's relative. I don't drink beer, don't smoke dope, don't eat out much, my car is paid for, and bikes and boats are my only 'mad money' expenditures. Spending $500 and getting a more compliant ride isn't much in the grand scheme of things.

    Bikes in general aren't much in the grand scheme of things, when you get right down to it. Read the headlines and see that there's a guy that's spending billions to take a plane ride around the moon. Another that's spending like $190 million -- in cash -- to buy a magazine. Hundreds of thousands of people are about to line up to pay $1k for a phone.

    None of it is right or wrong -- people get to choose how they spend their money.

  24. #124
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    Quote Originally Posted by One Pivot View Post
    You really dont think a ~$450 upcharge for spokes alone is a big deal? Maybe we're in different income brackets. Thats a ton for me.
    I thought wrong that was for complete set of wheels, so yeah I agree.

  25. #125
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    Quote Originally Posted by mikesee View Post
    There really isn't evidence of creep as yet, although I'll readily admit that it's still early days to make that call. I'm coming up on 10 months and ~2000 miles on my first set, and about to build myself another set for fatbike use.

    If your concern about creep is that the wheels will need to be retensioned, it's probably worth noting here that this happens to some extent with normal steel spokes too.
    Creep was not a concern for me on the Berd build. I wonder more about cosmetic fraying at either end of the spokes over time, more so at the hub hole interface I imagine.

    Of the ~8 wheel sets with varying sorts of steel spokes I am currently running, only one rear wheel required re-tensioning after a year or so.

    It is a Stan's stock Crest that had ridden a number of stairs and decent drops. I eventually swapped in an ArchEX hoop and it is still going strong.
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  26. #126
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    Wax them, like a bow string?
    Do the math.

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    Quote Originally Posted by Porkchop_Power View Post
    Everyone is confusing the two types of stiffness (or bending modes while riding). All the responses above relate to the wheel deflecting in the vertical direction (by a tiny amount compared with tires). This is generally not an issue. The bigger issue with wheels is lateral stiffness and bending. This can be demonstrated by putting the hub in a vice with the wheel horizontal and adding weight to the rims and seeing how far it deflects based on load. Wheels that are "flexy" in this bending mode are harder to steer and can even cause the tire to rub on the chainstays. This deflection is usually MUCH greater then the deflection noted above. Note that this is felt in cornering, particularily if you are heavy and really rail the corners. This is where Carbon really outshines aluminum as most of the deflection is cause by the rim stiffness. As to whether polymer spokes make much of a difference I do not have the data on it but expect it is still more a property of the rim.
    actually flexy wheels generally rub chainstays less.
    Bending modes? Try again...
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    Quote Originally Posted by meltingfeather View Post
    actually flexy wheels generally rub chainstays less.
    Bending modes? Try again...
    My experience was quite opposite of that, the flexy 29er wheelset would rub the chainstays under hard cornering.
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  29. #129
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    I think he meant rims. Stiff rims rub chainstays. A noodly rim will flex at the bottom only, like a wet noodle.

    This is a bigger deal on road bikes with narrow spacing. Becomes really obvious.
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    I have found frames play a HUGE part in this as well. People sometimes point at rims and ignore the frame aspect.

    But rubbing I have experienced as a big rider has always been more noodly rims when I'm on a properly built frame (big guy and XC frame doesnt mix well railing corners for me, more rubbing and flexing issues in the rear). The more lateral stiffness a wheel has the less issues I have pushing tire clearance in a frame.

    Have to say the more I watch this thread the more I want to save the funds for these. Thankfully by the time I can buy them the more time they are put through our level abuse and I'll know if they last well enough to justify the cost.

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    How would they rub the chainstay less since they are bending more? That makes no sense. I should have said deflecting more from the fixed hub but either way even with crappy old 26 wheelsets I could easily bend the lighter ones and rub the chainstay holding the bike still.

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    Quote Originally Posted by Porkchop_Power View Post
    How would they rub the chainstay less since they are bending more? That makes no sense. I should have said deflecting more from the fixed hub but either way even with crappy old 26 wheelsets I could easily bend the lighter ones and rub the chainstay holding the bike still.
    First, rereading my post it came off snarky AF... apologies.
    I meant rims... wheels can be flexy in different ways. If the rims are not stiff, they flex locally (at the point of applied force) but not much elsewhere. Stiff rims move more as a plane, where any displacement will result in movement all around the wheel. The phenomenon is influenced by other factors affecting the stiffness of the wheel, including the number, gauge, and lacing of the spokes, and the flange spacing of the hub.
    A wheel with a very stiff rim and narrow flange spacing or very thin spikes would be the worst case interns of ground displacements causing movement of the rim relative to the frame around the wheel (stay rub).
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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    Quote Originally Posted by Jayem View Post
    My experience was quite opposite of that, the flexy 29er wheelset would rub the chainstays under hard cornering.
    Individual experiences really dont offer much in a discussion of first principles and engineering. Im not discounting it, but the whole of the experience is unknown and performance trends or tendencies are quantified statistically, for which individual data points have little to no bearing.
    Im not sure what data you based you determination of flexy on for your wheel or any of the other circumstances surrounding your experience, but the fact that forces applied at the ground translated into movement of the wheel at the stays means that at least the rim was relatively (in the context of 29er mtb rims) stiff. If you had a few thin spokes or a rear triangle or axle fixture that were not stiff, any of those could have played a role, but arent attributable to the wheel in the latter cases.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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    Quote Originally Posted by RAKC Ind View Post
    I have found frames play a HUGE part in this as well. People sometimes point at rims and ignore the frame aspect.

    But rubbing I have experienced as a big rider has always been more noodly rims when I'm on a properly built frame (big guy and XC frame doesnt mix well railing corners for me, more rubbing and flexing issues in the rear). The more lateral stiffness a wheel has the less issues I have pushing tire clearance in a frame.

    Have to say the more I watch this thread the more I want to save the funds for these. Thankfully by the time I can buy them the more time they are put through our level abuse and I'll know if they last well enough to justify the cost.

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    You're mixing and matching terms and components here-- part of the reason why individual experiences can always be turned up as contradictory "evidence" when there are none of the factors that would qualify it as valid such as control, bias consideration, statistically significant number of samples. Most of the time in these discussions a meaningful fraction of the relevant basic facts aren't even offered, as in this case and that mentioned by Jayem.
    Lateral stiffness and a wheel's load-response behavior is affected by more than just the "noodliness" of the rim spec.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  35. #135
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    Quote Originally Posted by meltingfeather View Post
    Individual experiences really dont offer much in a discussion of first principles and engineering. Im not discounting it, but the whole of the experience is unknown and performance trends or tendencies are quantified statistically, for which individual data points have little to no bearing.
    Im not sure what data you based you determination of flexy on for your wheel or any of the other circumstances surrounding your experience, but the fact that forces applied at the ground translated into movement of the wheel at the stays means that at least the rim was relatively (in the context of 29er mtb rims) stiff. If you had a few thin spokes or a rear triangle or axle fixture that were not stiff, any of those could have played a role, but arent attributable to the wheel in the latter cases.
    Well, "flexy" was because it (stock alloy specialized wheelset) was rubbing the chainstays during hard cornering. I had never had a bike do that before. Tightening the heck out of the spokes, higher than normal, helped significantly and made it much more occasional, but didn't make it go away completely. Once I built up some carbon wheeled rims for the bike, the problem did go away altogether.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

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  36. #136
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    I sent an email to Berd, asking about creep, stiffness, loss of tension over time, etc. Here is their reply:

    Hi,

    Thanks for your email and your interest in our spokes. Yes, we haven't found any negative effects due to creep. We haven't found any negative effects of wheels being stored in a hot car, but you certainly want to keep the spokes away from extremely high temperatures. Our spokes are about 2/3 the stiffness of similar gauge steel spokes.

    What other questions can I answer? Are you interested in purchasing our spokes for a wheelbuild?

    Thanks,
    Charlie

    On Wed, Sep 19, 2018 at 5:11 PM <xyz@gmail.com> wrote:
    Have you researched/tested your spokes to determine how/if they are affected by loss of tension in assembled wheels over time due to creep? Are they sensitive to heat, such as the wheels being stored in the back of a hot car? How stiff are your spokes as compared to similar thickness stainless steel spokes? Thanks.

  37. #137
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    Quote Originally Posted by mikesee View Post
    There really isn't evidence of creep as yet, although I'll readily admit that it's still early days to make that call. I'm coming up on 10 months and ~2000 miles on my first set, and about to build myself another set for fatbike use.

    If your concern about creep is that the wheels will need to be retensioned, it's probably worth noting here that this happens to some extent with normal steel spokes too.
    I'm looking to build up a chinese carbon wheel and glad you brought this up.
    Creep is definitely an issue with Dyneema. Sk75, Sk78, Sk99 from DSM will all creep over time, even as low as 18C.
    At 30C, the wheels would detention is just a few weeks.
    However, just a few years ago, DSM released DM20 which was a massive improvement in creep. It basically flatlines even up to 30C. I don't think it's a coincidence that Berd LLC appeared about a year after DSM released this material.

    That said, I love to DIY, so I am planning to make a set of my own. I think you can make them for $1 or less per spoke. Dyneema is not that expensive.
    I've read Berd's patent, and it's dead simple. You literally cut off the end of a cheap spoke, attach the dyneema with super glue (with a certain length buried in the hollow braid; it grips like a chinese finger trap; the glue is just for no-load retention) and use a standard loop splice on the other end.

    @mikesee, is there a recommended internal nipple to use with these that you know of?

  38. #138
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    Dang, I wrote a reply and it dissapeared.

    I am glad you guys brought up creep.
    Creep is certaitnyl a concern with UHMWPE.
    DSM's SK78, even SK99 will all creep, even as low as 18C. Per DSM's data.
    At 30C, they would potentionally detension in just a few weeks.

    However, just a few years ago, DSM released their DM20 material, which is a huge jump in creep performance. It's basically flatlined, even at 45% breaking load at 30C.
    And even at 70C with 20% load its almost flatlined.

    I dont think it's a couincidence that Berd, LLC appeared just a year or so after DSM introduced DM20.
    I talked to Charlie @ Berd and he would not give me any assurance as to their creep data, only giving anectotal reports, which concerned me.
    I asked him to confirm if their material was at least as good as DM20 and he would not confirm, only to say that they use a "proprietary" material.
    They also use about 40% breaking load (assuming 120kg tension) which is pretty high. If they were using SK78 or SK99, their spokes would be terrible, so they must at least be using something better then that.

    Anyway, I love to DIY, and I'm cheap, so I am going to build a set myself.
    I have read their patent and it's dead simple. I think you could make them at home for less then $1 per spoke.
    Ive sourced some 1.8mm SK78 and Sk99 material for an initial build, but still looking for some 1.8mm or 2mm DM20. No one offers it yet.
    The Sk78 or SK99 should last quite a while in my mild climate in Washington. The 2mm sk99 stuff is also rated at 850kg, so i'd only be loading it to less then 13% breaking load which would really limit creep anyway.
    I don't know any 2mm steel spokes that could hold anywhere near 800kg. Impressive stuff.

    Here is a chart from a DSM presentation.
    DM20 is like 2 orders of magnitude improvement in creep.Berd spokes.-capture.jpg

    https://www.dsm.com/content/dam/dsm/...%20Dyneema.pdf

    @Mikesee Is there a recommended internal nipple to use with these spokes? I recall Charlie mentioned something about that.

  39. #139
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  40. #140
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    Very interesting, okashira! I'm interested to see your home made spokes when you get them.

  41. #141
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    Making the loop on the end is the tricky part. As is finding a suitable glue to attach the spoke end to the Dyneema.

    I think 3M makes a liquid acrylic glue specifically for HDPE. 8005, IIRC.


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  42. #142
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    He can just tie a knot at both ends and have some sort of expanding insert to tension.

  43. #143
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    Quote Originally Posted by Le Duke View Post
    Making the loop on the end is the tricky part. As is finding a suitable glue to attach the spoke end to the Dyneema.

    I think 3M makes a liquid acrylic glue specifically for HDPE. 8005, IIRC.


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    Berd says what glue to use right on their patent. It doesn't need to adhere well to the fibres.
    Btw you can use cyanoacrylate with PE or even PP with a primer. I happen to have some ...
    They also say how to make the loop as well. Very easy.
    They just use a standard bury splice.

  44. #144
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    Knots are generally a bad idea with uhmwpe. They weaken the rope and tend to slip out. You gotta splice. YouTube how to splice a loop in dyneema.

  45. #145
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    Quote Originally Posted by mikesee View Post
    Thanks. I meant to say internal nipples. My x1700's and my Chinese carbon rims coming are internal. When I mentioned it to Charlie at Berd, he said to use a specific one and I didn't write it down. I'd ask him but he's not replying to my emails anymore .

  46. #146
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    Well that's very interesting. A splice is almost 100% of the strength.

  47. #147
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    Quote Originally Posted by Schulze View Post
    Well that's very interesting. A splice is almost 100% of the strength.
    This is the specific splice Berd describes in their patent.
    They add a dab of super glue to the bury. (instead of twine)

    https://www.youtube.com/watch?v=9ND8Gfk_bVI

  48. #148
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    This is the specific rope I have on the way to try.
    https://www.velasailingsupply.com/g-...e-braid-1-8mm/
    ^^rated at 390kg
    https://www.epayments.co.uk/epages/e...MARD12MAX992mm
    ^^rated at 800-900kg

    These could also work:
    https://www.deckhardware.com.au/LIRO...K99-approx-2mm
    https://www.armare.it/en/linee-prodo...ce-99-for-kite
    ^^only 1.5mm and rated for 450kg!
    The 1.25mm is even rated for >300kg, could be good for a racing application. Would creep quite abit long term. 1.25mm would be pretty aero.



    In the long term, this is the stuff we need:
    https://www.cs-rigging.com/en/ropes/dyna-one-hs-max
    Dynastay DM20 Rope From English Braids (Also known as Spectra)
    https://www.marlowropes.com/product/m-rig-max
    Product

    Just in 1.8mm or 2.0mm size. I have some inquires out so have a reel custom braided.
    chicagoyachtrigging.com has gotten back to me and they are looking for a source of fibers so they can make some spools in 1.8mm size.

  49. #149
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    Chicago rigging found some!!
    1.8mm DM20!

    I have tried a dozen custom rope makes and all the major manufacturers so far. No idea how they found it.

    100m is enough to make about 10-12 29er wheels. I'll have extra.
    Attached Images Attached Images  
    Last edited by okashira; 2 Weeks Ago at 06:10 PM.

  50. #150
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    First try. This one is about 5mm too long. It's about half tight and I'm out of threads.
    https://youtu.be/PRnoW7By5vU

    It was not too hard at all. It took some practice/trial and error. With a good process I think 10-15 minutes per spoke.

    These I looped the splice around the hub like some suggested. I think this may be the easiest way to go. It's really hard to pull the eye through the hub hole like Berd has you do.

    It kinda goes like this:

    a. Prepare your spoke ends. I'd use some cheap double butted spokes. Ask your LBS or buy in bulk online. I found some 2.0mm / 1.7mm double butted spokes for like $0.4 each online...
    b. At the thread end, find where it tapers from 2.0mm to 1.8/1.7/1.5mm. Cut about 20mm into the 2mm section. You will want to have your LBS thread 15-20mm here and then it will taper immediately. (to save weight)
    c. Have your LBS thread the ends....
    d. Measure total length of about 75mm, cut and sharpen the end. Dull the end a bit so it's not super sharp.
    e. make sure you make a few extra just in case.

    You can skip the steps about double butted and cutting some exact length into the 2.0/1.7 taper if you don't mind a few tenths of a gram heavier. You will get a spoke about 3.0g.
    If you're careful like above you can get it to about 2.5g each.

    YOU WILL WANT TO SUPER GLUE BELOW THE THREADS AND ABOVE THE TAPER. IT'S OKAY IF YOU HAVE LONG THREADS AND SUPER GLUE TO THE END OF THE THREADS A LITTLE.
    The super glue does NOT hold the load. It's only there to allow the Dyneema to pull tight and squeeze down onto the shaft like a Chinese finger trap, and it grips the shaft like that.

    Something like this:

    Berd spokes.-untitled.jpg

    With a belt sander, it takes like 1 minute per spoke end.


    1. Splice the eye into the hub. Pull the tail tight and work the eye around while pulling on the tail to make it as tight as possible.
    2. Bury the tail by milking the line...
    3. grab the line at about 300mm out (use pliers to grab it hard) from the splice and pull it as hard as you can in the direction of the nipple, move it round to seat the eye into the hub.
    4. Pull the line taught, use a ruler, estimate the length and add about 10mm. TAKE NOTE OF THE LENGTH YOU CUT, USE A CONSISTENT REFERENCE FROM THE HUB SOMEWHERE USING A STIFF RULER.
    5. insert your spoke end into the end, through the center of the hollow braid until the end of the threads.
    6. Grip the very end of the line around the spoke end at the end of the threads, and pull the line taut.
    7. Verify you're happy with the length and super glue the end right at the end of the threads.
    NOTE: YOU WILL WANT THE SPOKE TO BE AS SHORT AS POSSIBLE SO THAT IT BARELY THREADS INTO THE NIPPLE. THIS IS BECAUSE THEY WILL STRETCH A BIT AND THE SPLICE WILL BED INTO THE HUB A LITTLE.
    8. Do a quick pull test. Grab the spoke end with pliers and pull it super taut in the direction of the nipple, work it around to bed in the splice. and thread into the nipple. Make sure to hold the spoke so it does not rotate and rotate the nipple
    9. You're done! proceed with tensioning like usual and re-tension again after 2 hours. Then again after 24 hours like Berd says.
    10. If the spoke was too long or too short, take note of the length you cut in step 4, try again with a shorter or longer one.

    You will also want to add some super glue to the end of the bury at your splice so it doesn't slip any.

    If folks are interested, I can make a video or a better write up...
    I am going to do some load and break testing as well.. just working on the process...

  51. #151
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    Wow. Very impressed with your work here. Well done.

    I wonder if Berd will drop their prices now...




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  52. #152
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    Quote Originally Posted by okashira View Post
    First try.

    Super cool DIY project. Deserves more detail as you learn from your mistakes.

    Should also be it's own thread -- inappropriate to take this one hostage.

  53. #153
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    Call me intrigued. I find the this all interesting. With the spoke nipple interface still being a traditional combo, is it likely we would see any fatigue life increase? In my experience, when I break spokes, it's almost always at or near the nipple.

    I would think the primary benefit is weight reduction which is significant.

  54. #154
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    Thanks a ton for posting all this info, I am very intrigued. I will have to take some time to read up on this and how you did it. Makes sense.

  55. #155
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    Quote Originally Posted by okashira View Post
    The super glue does NOT hold the load. It's only there to allow the Dyneema to pull tight and squeeze down onto the shaft like a Chinese finger trap, and it grips the shaft like that.
    Click image for larger version. 

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    How long do you really think that spoke shaft needs to be? I guess I'm wondering what length it takes for dyneema to wrap around that shaft under tension like a finger trap? (great example, btw).

    I'm also contemplating why we jump to spoke-like materials without trying to innovate a little bit, since splicing is something that can potential save a lot of weight working with dyneema.

    How does PiRope secure their end bolts to the strings? Could we do something similar with Dyneema or is there a difference in the properties of the two materials that would make this a bad thing to do? I can see potential for a lighter system if a nipple-like bolt could just be "glued" to the end of the dyneema fiber, which can then be tensioned with a nut on the inner rim bed.

    There must be another way to do this!
    Last edited by sissypants; 2 Weeks Ago at 10:48 AM.

  56. #156
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    Cool DIY product but I can help but feel some concern for the developer who came up with this product having his hard work taken apart, and copied.

    That said, if the technology proves to provide no downside (except for cost) then I would incorporate it in to my next wheel build. However I'd purchase a complete package from an experienced provider.

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  57. #157
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    Quote Originally Posted by mikesee View Post
    Super cool DIY project. Deserves more detail as you learn from your mistakes.

    Should also be it's own thread -- inappropriate to take this one hostage.
    +1 jeesh
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  58. #158
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    I'm still curious why you couldn't take a line half the size and make a loop. It would have to be easier than doing 5 dozen ish miniature splices at 10-15 minutes each.

  59. #159
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    In basic theory, no. The spoke end/nipple will see all the same loads.
    you could move to a 13g nipple for more strength there.

    However, the UHMWPE material has a nice ability to damp some high frequency loads and shock loads which may increase the fatigue life of the spoke end / nipple.

    @Suns_PSD A bit hard for me to take them apart given Berd won't sell me spokes. I learned everything from their patent and some basic engineering knowledge.
    Not many will pay $1200+ for a set of 4 wheels of spokes (that's what you will pay for the spokes, labor, and trouble of shipping them hubs and rims)
    I'm happy to give others an option to build their own at home.
    I have all but confirmed that they(Berd) do in fact use DM20 material, Marlow (large rope manufacturer) has an NDA and an exclusivity agreement with some company for 1.8mm DM20 stranded Dyneema.
    Anyway, we can take this to another thread at the OP's request.

  60. #160
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    Quote Originally Posted by Darth Lefty View Post
    I'm still curious why you couldn't take a line half the size and make a loop. It would have to be easier than doing 5 dozen ish miniature splices at 10-15 minutes each.
    You could. But you need a way to tension the spokes, thus a threaded end... The splice actually only takes 1-2 minutes.

  61. #161
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    Quote Originally Posted by okashira View Post
    In basic theory, no. The spoke end/nipple will see all the same loads.
    you could move to a 13g nipple for more strength there.

    However, the UHMWPE material has a nice ability to damp some high frequency loads and shock loads which may increase the fatigue life of the spoke end / nipple.

    @Suns_PSD A bit hard for me to take them apart given Berd won't sell me spokes. I learned everything from their patent and some basic engineering knowledge.
    Not many will pay $1200+ for a set of 4 wheels of spokes (that's what you will pay for the spokes, labor, and trouble of shipping them hubs and rims)
    I'm happy to give others an option to build their own at home.
    I have all but confirmed that they(Berd) do in fact use DM20 material, Marlow (large rope manufacturer) has an NDA and an exclusivity agreement with some company for 1.8mm DM20 stranded Dyneema.
    Anyway, we can take this to another thread at the OP's request.
    You should start a new thread.

    Your ambition and specific information is impressive! I agree that Berd is using the DM20 material. This makes sense based on their public release date and the release date of DM20 being one year earlier, their patent info describing the specific properties of the material, and also the fact that only DM20 is particularly stretch-resistent.

    I was on the fence about saving up for Berds, but no longer.

    It's confusing to me how Pi-Rope can be using such an elastic material and yet claim the same tension-and-forget marketing pitch that Berd is using. It seems to me that Pi-Rope spokes should require constant re-tensioning.

    Does this exclusivity agreement mean that we can't order 1.8mm DM20 stranded Dyneema from Marlow?

    What about using 1.2mm DM20 Dyneema? Is this too narrow? We aren't trying to lift lead-heavy riggings with this stuff.

  62. #162
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    Quote Originally Posted by okashira View Post
    You could. But you need a way to tension the spokes, thus a threaded end...
    Sure. But it could be a screw eye.

    The splice actually only takes 1-2 minutes.
    Well you'd get some practice! :-D

  63. #163
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    Quote Originally Posted by Suns_PSD View Post
    Cool DIY product but I can help but feel some concern for the developer who came up with this product having his hard work taken apart, and copied.

    That said, if the technology proves to provide no downside (except for cost) then I would incorporate it in to my next wheel build. However I'd purchase a complete package from an experienced provider.

    Sent from my SM-G892A using Tapatalk
    Yeah AHHHH, that is kina the whole point.

    I can DIY all sorts of things (that could fail epically) and prefer purchasing bike components from someone who has done the proper R&D and actually got the spokes race certified... certainly a non-trivial task.

    DIY discussion in this thread is super bad form IMO; just sayin...

    There are herds of people who have paid $2k or more for wheel sets so going gonzo on spokes/nipples is not all that outlandish in the grand scheme of things.

    I got the new/unboxed DT 240s hubs for $200 from someone who decided boost and <32 holes was "the thing they needed". Threw some of that savings at spokes... no big deal.

    I'm in a solid financial spot where it is feasible for me to pay the freight for something relatively new and different... sure, the cost will most likely go down over time as Berd produces more and the design may change too... all good by me.
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  64. #164
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    Since wheels are held together in tension thinner spokes of the same material will flex more because the thinner spokes stretch more. Stretch in engineering terms is called strain and is measured as in/in or mm/mm. Anyway, if the berd rope has less strain, then the the rope will stretch less and result in actually less flex.

    But a stiff rim changes the way a wheel flexes. A lightweight aluminum rim will bend when it flexes, whereas a stiff carbon rim will resist bending and rotate laterally around the hub which may in some cases result in a wheel that flexes more depending on where you are taking your measurements.

    Since carbon rims are generally much stiffer than aluminum rims they will be much stiffer vertically as long as the spokes remain in tension. Since aluminum rims can more easily bend at a single area they can allow the spoke tension to drop in that area, whereas a carbon rim has a greater ability to remain round under load and activate all spokes together.

  65. #165
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    This is really interesting and I hope he continues to post. Mikesee posts his wheel-selling spam on boards all the time, so I don't see any issues with the guy continuing to post his DIY stuff on this thread.
    Last edited by Jayem; 2 Weeks Ago at 03:24 PM.
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  66. #166
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    Quote Originally Posted by changingleaf View Post
    Since wheels are held together in tension thinner spokes of the same material will flex more because the thinner spokes stretch more. Stretch in engineering terms is called strain and is measured as in/in or mm/mm. Anyway, if the berd rope has less strain, then the the rope will stretch less and result in actually less flex.

    But a stiff rim changes the way a wheel flexes. A lightweight aluminum rim will bend when it flexes, whereas a stiff carbon rim will resist bending and rotate laterally around the hub which may in some cases result in a wheel that flexes more depending on where you are taking your measurements.

    Since carbon rims are generally much stiffer than aluminum rims they will be much stiffer vertically as long as the spokes remain in tension. Since aluminum rims can more easily bend at a single area they can allow the spoke tension to drop in that area, whereas a carbon rim has a greater ability to remain round under load and activate all spokes together.
    I'd like to add that the flex of aluminum rims on a decent wheel build may not be detectable by many riders (including me). Some of my friends who are crazy amateur podium sorts of people can tell the difference but honestly, I can't.

    During a wheel build, I definitely notice there are more "nuances" (in a smaller area) to maintaining trueness with aluminum rims but once they are built, they hold up quite well- similar to carbon for me (I've hit staircases in addition to rocks, roots and dirt with all of them).

    The downside with a Berd build is that it takes more time for sure. I was quite surprised that the spokes all settled in with a consistent number of threads showing. Somehow I had it in my mind that the spoke stretch/strain would be more variable with non-rigid material.

    Another factor on the build side is the size of the hub flange. I run Chris King large diameter (LD) 15mm 29er front hubs (short spokes 284mm) with 135mm rear hubs on ~50% of bikes in my stable and DT 240s's for most of the remainder (including the Berd build).

    I'm hoping to have a pro friend ride my Berd wheel set at some point (now that race season is over) and see what he thinks. My "amateur+" friends are in two camps: super light builds with bladed spokes are "the only way" (never been my thing). The other camp seems obsessed with stiffness... 35mm+ rims with big straight spokes (and I9 hubs that need ~yearly bearing replacements lol). I don't have much dental work but prefer something with a little forgiveness.

    Some in both camps are convinced that I am going to have a catastrophic failure with the Berd build. I've given up on trying to convince them otherwise. I recently rode in the Michaux, PA Terror of Teaberry event on them and my body took almost a week to recover. Wheel set was no worse for the wear.
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