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  1. #1
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    Make your own polymer (UHMWPE) spokes?

    Hi guys

    I want to make my own set of polymer spokes.

    I initially was going to dive in and purchase a set of Berd spokes,
    But after talking to them, they didn't give me the warm fuzzies in terms of their long term performance (specifically, creep)
    Now they won't even sell me a set at all. :-D

    So, I'm gonna make my own.
    This is a continuation from the berd spokes thread.
    I posted up a preliminary procedure here:
    Berd spokes. - Page 2- Mtbr.com

    Basically, Berd's design is dead simple. It's a standard bury splice at one end and the other end they bury a cut 2mm spoke end at the other end.
    They use a dab of super glue at both ends to prevent the bury from slipping at both ends.

    On both ends, the bury is held in via a Chinese finger trap method.. this is typical for rope splicing. The glue does not take the load; it's only there to help the rope develop some initial tension and clamp down on the bury holding it via friction.

    The devil is in the details. splices tend to take a set and slip a bit, making the length difficult to get right.


    On to materials,
    After my research, it seems DM20 is the way to go for UHMWPE. It's a new material from DSM with massively improved creep characteristics.
    UHMWPE is so bad with creep, standard high performance materials would simply be unsuitable for spokes, until just a few years ago.
    I have a 100M reel of 1.8mm DM20... from Marlow on the way.

    Another couple of options: Vectran and PBO. Both have good creep characteristics and could be used for spokes.
    Everything here applies to those too if you were to source 1.5-2.0mm Vectran or PBO.

    Read the link above for info on my initial try. I will try to update this thread with my efforts...

    I have another idea to get the weight down to ~1.9g per spoke and an even better/easier design. Here is what I came up with:

    Make your own polymer (UHMWPE) spokes?-capture.png
    I am thinking to take a butted spoke, 2.3mm/2.00mm, and roll or press or stamp the end to 0.8mm thick to achieve an eye where it threads into the nipple. This way one could do a 2nd bury splice here eliminating the long metal bury. This part comes to ~0.65 g each and with a rope weight of about 1.2G = 1.85G per spoke!!

    This compares to about 2.5-2.6G per spoke I'm getting with Berd's method because of the longer steel spoke end that needs to be buried.

    The strength of the part is still a bit iffy. It would be better if we could find some 12g/14g butted spokes (2.6mm/2.0mm) so there's more material to smash to make the eye... or even 11g or 10g.
    That or the part could be made custom from scratch...
    I know several manufacturers whom could make such a part but it would need to be a pretty large qty to be cost effective.
    For example:
    https://www.gallmachine.com/gallery
    THB, a spoke manufacter would be best suited to make such a part...

    Here is a "quick" FEA assuming 60,000psi yield strength. I know alot of spoke manufacturers get their yeild strength to 120,000psi and up, but's it's still pretty iffy and more material would be nice.

    (link incoming)
    Last edited by okashira; 2 Weeks Ago at 05:41 PM.

  2. #2
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    In the amount of time it took you to type that post, I could have ordered some double butted DT spokes. Kinda like the ones on my Chris King hub/Dt spokes/WTB Frequency Team rim that has been solid for 5 years of 1500-2000 ft descents. Granted, that wheelset should implode at any moment (really, its thrashed). Sorry to be kinda brutal, but just buy some spokes and go ride your bike, man. You dont need to re invent the wheel. Too mean?

  3. #3
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    Cool story, bro

    Here's the image


    Pretty iffy.. that's only 100kgf load.
    Maybe a good choice for a high spoke count wheel and 1.5mm line.
    I think it might be better to get some 12ga spokes and belt sand down and end to 2.0mm for threading, use the 12ga section to create the eye.

    I think I'll focus on making a wheel with the "spear" method first... getting distracted.
    Last edited by okashira; 2 Weeks Ago at 12:01 PM.

  4. #4
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    I can see how this could be viewed by some as a waste of time, but count me interested.

    Sent from my Pixel XL using Tapatalk

  5. #5
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    Yes, its interesting. I would like to ride some of these sring wheels. OP got me to check out Berd Spoke site.

  6. #6
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    I still think there's got to be a way to do it without splicing. Everything I've thought of so far though would be a skosh heavier... still lighter than steel, though.

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    I like where you're going with this.

    Another option is to make the anchor out of aluminum - easier to manufacture, lighter, allows for custom colors. Bump up the diameter of the threads and make the nipple an internal nipple like the I9 spoke system.

    Prototyping could be done with 3d printing. In fact you could send the CAD model you have to a number of companies and have examples in your hand in a few days.

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    Interested in what okashira comes up with.

  9. #9
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    Quote Originally Posted by okashira View Post
    Click image for larger version. 

Name:	Capture.PNG 
Views:	119 
Size:	94.2 KB 
ID:	1222704
    I am thinking to take a butted spoke, 2.3mm/2.00mm, and roll or press or stamp the end to 0.8mm thick to achieve an eye where it threads into the nipple. This way one could do a 2nd bury splice here eliminating the long metal bury. This part comes to ~0.65 g each and with a rope weight of about 1.2G = 1.85G per spoke!!
    This is the way to go. You're taking advantage of the ability to splice rope and saving weight as a result, plus you're doing away with the inelegant super-glued spoke shaft mechanism.

    You're basically looking for a 2-56 (2mm x 56 tpi) eyebolt which can thread into a standard alloy nipple. The threads should be long enough to compensate for any variation in string lengths. Something in the likeness of this:

    Name:  eyebolt.png
Views: 631
Size:  134.8 KB

    A 2-56 alloy eyebolt like this likely isn't commercially available, but I bet it could be stamped quite easily. Ti might also be practicable, but more expensive.

    Using eyebolts over inserted spoke shafts is an advantage when building the wheel, since twisting the rope can be prevented during nipple tensioning. It also has the potential to be lighter.

    For the critics out there, please quit sucking the life out of innovation. Berd has a cool product, and they've worked hard to protect their idea and market opportunity. But I think it's possible to do even better than Berd, so why not just let this guy figure it out? I'm subbed and may be ready to jump in on the project financially if needed.

  10. #10
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    Quote Originally Posted by Darth Lefty View Post
    I still think there's got to be a way to do it without splicing. Everything I've thought of so far though would be a skosh heavier... still lighter than steel, though.
    This is basically what Pi-Rope is doing, using adhesive (I presume), although I'm not sure. In any case, they are using different materials.

    Thing is, if you want it to be as light as possible, you don't want to be using materials other than the rope as much as possible. So on the hub end you have to splice to avoid using a bolt of sorts, and you can't just tie a knot because that will creep.

    On the nipple end of the spoke you've either got to use a threaded spoke shaft inserted into the core of the rope, or do another splice around an eyebolt of sorts. Either way, it's going to be very labor-intensive.

  11. #11
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    Just remembering now here that a Fiber Fix spoke does not use the threads at first, only for adjustment. It cinches under its own tension - sort of like the finger cuff mentioned above.

    Has anyone built a whole wheel with Fiber Fix spokes? Only sort of kidding :-D

    Photo found at Peter White Cycles
    Attached Thumbnails Attached Thumbnails Make your own polymer (UHMWPE) spokes?-fiberfix.jpg  


  12. #12
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    Just sent out a swarm of Alibaba inquiries for rod-shaped alloy M2 eyebolts, specifically asking for a 30mm 56tpi-threaded rod immediately adjacent to an eye of 4mm in diameter. I set my MOQ to 1000 but said I was flexible. I also asked what kind of tension these bolts can handle, and, if it helps at all, said the bolt should be lightweight.

    I'll see what kind of information I can learn, and whether these bolts could be a viable option.

  13. #13
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    I dont know why the FEA image doesnt work; try here:

    https://i.imgur.com/BKNIEwH.gif

    I did find a #2-56 threaded eyebolt commercial
    https://www.amazon.com/Sullivan-Prod.../dp/B0006O8OA8
    But I don't need to do an FEA to determine that would be way to weak. Probably wouldn't even take 15kg.

    @sissypants 2mm hole.
    I can make some drawings and cad file if you want to send to suppliers.

    I can easily prototype this by brazing the threaded end of a spoke to a drilled piece of spring steel(for strength) sheet with a hole drilled.
    That or I can use a press and stamp and end of a 2.6mm spoke.
    My chinese carbon rim came in over the weekend, and it's only drilled for internal nipples 14g. So I can't fit anything larger then that. :-/ If I use a 12g spoke I'll need to machine one end down to 2.0mm and thread it.

  14. #14
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    Quote Originally Posted by sissypants View Post
    Just sent out a swarm of Alibaba inquiries for rod-shaped alloy M2 eyebolts, specifically asking for a 30mm 56tpi-threaded rod immediately adjacent to an eye of 4mm in diameter. I set my MOQ to 1000 but said I was flexible. I also asked what kind of tension these bolts can handle, and, if it helps at all, said the bolt should be lightweight.

    I'll see what kind of information I can learn, and whether these bolts could be a viable option.
    I don't know if you did mentioned it, but spoke threads should be rolled instead of cut.

    Other option that occurred to me was to bend a spoke and braze it with brass.

  15. #15
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    Quote Originally Posted by okashira View Post
    @sissypants 2mm hole.
    I can make some drawings and cad file if you want to send to suppliers.
    Any drawings would help! I am hopeless with CAD even though I've tried, if I could redo my education I'd go for mechanical engineering

    This is the best I've done

    Make your own polymer (UHMWPE) spokes?-picture1.png

    A 2mm hole would be just enough to fit a 1.8mm rope, but I guess that's all that's needed?

    I think made-to-order Titanium bolts would actually be the best bet -- stronger and lighter. They also won't be too expensive. Titanium right from the manufacturer is much cheaper than bike-specific parts sold by the piece on Amazon from second-party dealers.

    I think your plan for a prototype bolt would work, but I wouldn't want to repeat that 24, 28, or 32 times! I think some bolt can be sourced that will be strong enough and affordable.

    I'm putting my bets either on Allied Titanium or a specialty Titanium bolt manufacturer in Shenzhen, China. Inquiries sent to both.

  16. #16
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    Quote Originally Posted by Aglo View Post
    I don't know if you did mentioned it, but spoke threads should be rolled instead of cut.
    Good point, thanks for that!

    Other option that occurred to me was to bend a spoke and braze it with brass.
    I'm not sure I see what you're after?

  17. #17
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    Your drawing is pretty good. Yes I don't think we need more then 2mm. If we end up sourcing 2mm rope we may need something like 2.1mm to fit it.
    just add another thing to your drawing:
    outside diameter around the 2mm hole ~4-5mm
    Change 30mm to ~20-22mm maybe.
    Titanium with rolled threads would be nice.
    On that note this could be another source for DM20 in something like 1.5mm - 2mm size. Just remove the polyester cover. I have some samples coming.
    https://www.mastrant.com/on-line-sho...-m-3-mm-1-8-in
    https://www.mastrant.com/on-line-sho...m-2-mm-3-32-in

  18. #18
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    Quote Originally Posted by sissypants View Post
    Good point, thanks for that!



    I'm not sure I see what you're after?
    I think he means take a 14gauge spoke, bend it around to make an eye and braze it.
    I am not sure it will be strong enough (it will elongate the eye.)

  19. #19
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    If a supplier has trouble with the #2-56 threads, perhaps just ask them to supply 2mm rod only.
    Then they can be rolled manually with a Hozan tool.
    On that note, does anyone have a Hozan tool? I would like to know how close to an eye the hozan tool can roll threads. What sort of spacing to the flange from the end of the threads is needed?
    I know a Phil wood tool will not work. It will only roll about 10mm of threads. We need 15-20mm IMHO.

  20. #20
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    Quote Originally Posted by okashira View Post
    I think he means take a 14gauge spoke, bend it around to make an eye and braze it.
    I am not sure it will be strong enough (it will elongate the eye.)
    Yes, that's what I meant.
    The elongation of the eye, and if the braze will hold are my biggest concerns, but wanted to post to know your thoughts on it.

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    Shouldn't the inside of the eye around the corners be less sharp, or it's not a problem?

    If we are passing the splice through the eye shouldn't the eye be a bit bigger as we are passing "two" threads through it?

    Sent from my Nexus 5 using Tapatalk

  22. #22
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    I'll take okashira's recommendation to reduce the rolled thread length to 20mm. I'm a weight weenie after all. Here's the updated drawing. I'm currently negotiating with Allied Titanium.
    Make your own polymer (UHMWPE) spokes?-bolt-specs.jpg

    Can a Hozan tool roll Titanium? It might be intended for only alloy and steel, pardon my ignorance.

    I'm afraid that bending a spoke to make an eye would severely compromise the strength of the material and it might not hold, although I like the idea. It's not hard to bend a spoke, so unbending that wouldn't be too hard either.

    That Mastrant rope looks really affordable! Are you sure the DM20 rope is easy to extract? Is it just a matter of pulling it out? Or did they use adhesive of any sort?

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    Thinking outside the container here, but what if the spoke was a loop of material? It would then require only one splice and it can be a rope splice, which I think is easier. It will double up the spoke, but theoretically the tension in each half of the loop will be half the total spoke tension, so you could use half the rope diameter. It should save weight because you only need metal on the nipple side. See attached diagram.

    Sent from my SM-G930T using Tapatalk

  24. #24
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    Quote Originally Posted by d-ron View Post
    Thinking outside the container here, but what if the spoke was a loop of material? It would then require only one splice and it can be a rope splice, which I think is easier. It will double up the spoke, but theoretically the tension in each half of the loop will be half the total spoke tension, so you could use half the rope diameter. It should save weight because you only need metal on the nipple side. See attached diagram.

    Sent from my SM-G930T using Tapatalk
    I mentioned the loop idea in the other thread (ha) and that's what the Fiber Fix does. But the cow hitch won't work, the rope is too big to pass two strands through.

    It would be cool to have a system that did not rely on getting the length exactly right on every spoke.

    If you were designing this from scratch it wouldn't be out of line to make a hub to go with them...

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    Or a rim

    Sent from my Pixel XL using Tapatalk

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    Copy all. This is a neat design exercise here. I'm really curious to see how it turns out. Keep us updated.

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    Just for the record, it is entirely possible that a rope/fiber supplier would consider or give an exclusive supply agreement to one player in the bicycle or spoke industry.

    Kind of a precarious way to protect an "invention," but stranger things have worked. Berd may be applying for a patent, also.

  28. #28
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    Quote Originally Posted by sissypants View Post
    I think made-to-order Titanium bolts would actually be the best bet -- stronger and lighter. They also won't be too expensive. Titanium right from the manufacturer is much cheaper than bike-specific parts sold by the piece on Amazon from second-party dealers.

    I think your plan for a prototype bolt would work, but I wouldn't want to repeat that 24, 28, or 32 times! I think some bolt can be sourced that will be strong enough and affordable.

    I'm putting my bets either on Allied Titanium or a specialty Titanium bolt manufacturer in Shenzhen, China. Inquiries sent to both.
    Titanium is a poor design choice.

  29. #29
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    Quote Originally Posted by Schulze View Post
    Titanium is a poor design choice.
    What is a better design choice? I'm no materials expert but I thought titanium was about four times as strong as alloy. Going with steel would defeat the purpose.

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    Aluminum would fill the strength requirements while being cheaper and lighter.

  31. #31
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    Quote Originally Posted by d-ron View Post
    Thinking outside the container here, but what if the spoke was a loop of material? It would then require only one splice and it can be a rope splice, which I think is easier. It will double up the spoke, but theoretically the tension in each half of the loop will be half the total spoke tension, so you could use half the rope diameter. It should save weight because you only need metal on the nipple side. See attached diagram.

    Sent from my SM-G930T using Tapatalk
    Cool idea, but yeah, I'm afraid the cow hitch would be a bit challenging. I could see threading this through a straight pull hub itself, but then the wheel builder is the one who has to do the rope splicing, and that gets challenging very quickly. You could use a hook instead of an eyebolt at the nipple site, but then you have an issue of spokes falling off the hook when not tensioned.

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    Quote Originally Posted by Aglo View Post
    Shouldn't the inside of the eye around the corners be less sharp, or it's not a problem?

    If we are passing the splice through the eye shouldn't the eye be a bit bigger as we are passing "two" threads through it?

    Sent from my Nexus 5 using Tapatalk
    Yes it's a problem. They need to be nicely rounded. This can be done manually or by the supplier.

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    Quote Originally Posted by Aglo View Post
    Shouldn't the inside of the eye around the corners be less sharp, or it's not a problem?

    If we are passing the splice through the eye shouldn't the eye be a bit bigger as we are passing "two" threads through it?

    Sent from my Nexus 5 using Tapatalk
    I'm not going to pass the splices thru the eye; not a fan of the method. I prefer to splice directly into the hub. This also allows for a smaller hole.
    Like this
    Make your own polymer (UHMWPE) spokes?-capture.jpg

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    Quote Originally Posted by Schulze View Post
    Aluminum would fill the strength requirements while being cheaper and lighter.
    I think that is iffy. The problem is the threads. They will work initially for some rolled 7075; but will fail with fatigue.

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    Yes you can do that. I think it wouldn't look as nice though. :-D
    youtube how to splice a continuous loop.

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    I suppose 7075 or better could work. The nipples are aluminum after-all. But I wouldn't want to do with 14g. 13g would be better. male threads are weaker then female, especially at this small size.
    Are there 13g aluminum nipples?

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    What prevents one from building a wheel from one continuous string, tensioned at a single nipple? The string would be threaded in the order in which a wheel is typically built.

    In theory, at least...

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    Quote Originally Posted by sissypants View Post
    What prevents one from building a wheel from one continuous string, tensioned at a single nipple? The string would be threaded in the order in which a wheel is typically built.

    In theory, at least...
    Have fun truing your wheel :-P
    And your final tension adjustment would need to be crazy long... like 200mm!

  39. #39
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    Quote Originally Posted by okashira View Post
    (...)
    Are there 13g aluminum nipples?
    Sapim makes them, don't know how hard is to source them.


    Quote Originally Posted by sissypants View Post
    What prevents one from building a wheel from one continuous string, tensioned at a single nipple? The string would be threaded in the order in which a wheel is typically built.

    In theory, at least...
    I like the way you think, but I don't think that will work.
    And imagine if a spoke fails, you would be biting the dust real quick :/.

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    Quote Originally Posted by okashira View Post
    Have fun truing your wheel :-P
    And your final tension adjustment would need to be crazy long... like 200mm!
    Oops I knew I was underthinking something. Now I feel stupid :/

    Your splice into the hub is really nice, it looks sharp!

  41. #41
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    Quote Originally Posted by Aglo View Post
    If we are passing the splice through the eye shouldn't the eye be a bit bigger as we are passing "two" threads through it?
    So there are two ways I see how to do this:

    1. Splice through a 2mm eye (so the loop passes through the eye) such that the rope is only 1.8mm thick.

    2. Use the splice joint as a "knot" to prevent passing through the 2mm eye, such that the rope will be 3.6mm thick at this point.

    The loop itself will not be 3.6mm thick, it will only be 1.8mm thick.

    I hadn't considered #2 until I re-read your post. Maybe #2 is the best way to go, since otherwise the spoke will have to be spliced onto the hub (the way okashira is doing it) AND onto the eyebolt. This would be unreasonably demanding for a non-DIY project and also make controlling the length of the rope quite challenging.

    Although I really like how okashira splices right onto the hub since that is the cleanest solution, I'm inclined to build the spoke without the hub or eyebolt, and use the splice joints as stable "knots". Think about how hard it would be to replace a spoke if you didn't have your splicing tools on hand, or didn't know how to splice.

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    Here is a improved design.
    This one assumes a 2mm shaft butted to 2.7mm. Smash the 2.7mm end to 1.17mm thick.Make your own polymer (UHMWPE) spokes?-capture1.jpg
    Make your own polymer (UHMWPE) spokes?-capture2.png

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    This one still only weighs 0.86g.
    304 or 302 stainless is probably the best starting point. It's cold worked so easily and the same material used for most spokes already.

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    Impressive stuff here
    https://www.armare.it/en/arc?arc[ide...catoreCalza]=0

    1mm and 200kg break strength!!
    Could make amazing spokes for race spec wheels.
    Use thinner 2.0.2.3 butted spokes with the smaller hole and go for 60kg max tension.
    Coulld be pretty aero (1mm!!!) and ~1.7g per spoke.

    SK99 means creep, though.
    The 1.5mm stuff is good for 450kg

  45. #45
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    Quote Originally Posted by okashira View Post
    I think that is iffy. The problem is the threads. They will work initially for some rolled 7075; but will fail with fatigue.
    Al spokes (yes, with threads) have been done for decades.

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    With 14ga threads?

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    The last design is no good.
    Pressing the eye to one side puts too side load and bends the threads.
    I'll revise and center it again

    Ignore this, bad analysis.
    Make your own polymer (UHMWPE) spokes?-1.gif
    Last edited by okashira; 2 Weeks Ago at 03:07 AM.

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    Centered...

    I do take it back on the above analysis.
    I assumed that the load was parallel to the shaft. In reality the splice and the nipple can swivel. I think either design will work.
    Attachment 1222941
    Attachment 1222942

  49. #49
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    I think I have a problem. How can one end of the rope be spliced onto the hub AND the other end be spliced onto the eyebolt?

    There are two directions to approach this, neither of which work:

    1. Splice the rope onto the hub using a standard Brummel lock
    2. Splice the eyebolt onto the rope using a one-side-fixed Brummel lock, but it's impossible to pull the eye through point A (see 0:57 here, https://www.youtube.com/watch?v=4WW7Qvg3VjI) because the bolt is fixed inside the loop. The bolt will be at least 4mm in diameter at its widest point.

    Alternatively,

    1. Splice the eyebolt onto the rope with a standard Brummel lock
    2. Splice the rope onto the hub using a one-side-fixed Brummel lock, but again, it's impossible to pull the eye through point A (see 0:57 of above video) because the loop is fixed to the hub.

    So the eyebolt has to go first no matter what. The only way I see this working is the following:

    1. Use a rope with 1mm diameter (small enough that a spliced loop can fit through a hub spoke hole
    2. Splice the eyebolt onto the rope with a standard Brummel lock
    3. Splice a loop into the other end of the rope with a one-side-fixed Brummel lock.
    4. Pull the loop through the spoke hole in the hub
    5. Secure the loop in place behind the spoke hole in the hub using a small metal rod (old spoke?) and simultaneously engage the eyebolt with the rim nipple to maintain tension on the spoke. Maintaining tension will prevent the small metal rod from falling out.

    All of the sudden this is getting way too complicated, and we need a 1mm rope made from a non-DM20 material.

    So, I'd like to consider a point brought up previously by d-ron of using a continuous loop. In this case the rope would be spliced once after being threaded through both the hub and the eyebolt. However, we are now using twice as much rope, so weight savings are negligible. Hence, once again this is not satisfactory.

    Maybe threaded spoke shafts are the only way to go?

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    You can just use the method okashira posted on the other thread.

    https://youtu.be/9ND8Gfk_bVI

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    Quote Originally Posted by Aglo View Post
    You can just use the method okashira posted on the other thread.

    https://youtu.be/9ND8Gfk_bVI
    Thanks for bringing that back up! I guess that works. A stitched whipping isn't as solid as a physical lock in the splice, but as long as the spoke stays under tension it should work fine, I guess.

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    I don't see how you can do a splice at both ends and maintain the tolerances you need

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    Quote Originally Posted by Darth Lefty View Post
    I don't see how you can do a splice at both ends and maintain the tolerances you need
    1. Make a Brummel lock splice at one end of the DM20 rope
    2. Measure the desired length on the rope from the end of the loop created in step #1 and mark with a sharpie (mark A). Make two additional marks (mark B & C) 5mm on either side of the first mark.
    3. Slide the eyebolt so that it covers mark A.
    4. Perform a simple splice into the rope through mark B, then pull the rope through until mark B and C are both at the junction of the loop.
    5. Pull the rope taught and fasten with a stitched whipping.

    To install the spoke, you'd pull the loop through the hub flange just like Berd does and secure it with a small piece of rope before pulling it back taut.

    You could even do steps #2-5 on the wheel with the eyebolt engaged with the nipple 1-2 turns, so you know your spoke length will be correct. Then you have ~15mm for additional tension.

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    A bury splice is actually stronger then a brummel lock splice. Because the lock puts shear stress on the line. That said a lock splice may be a better choice for tolerances...

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    Here is how to do lock splice with one side already in the hub
    https://youtu.be/4WW7Qvg3VjI

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    'You could even do steps #2-5 on the wheel with the eyebolt engaged with the nipple 1-2 turns, so you know your spoke length will be correct. Then you have ~15mm for additional tension."


    This is exactly what I plan to do. Even better if you make a jig that has you make the splice while the eye is threaded into a dummy wheel that will intentionally make the line a couple mm too short. Then rely on splice and line settling to get that extra 2mm back

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    Quote Originally Posted by okashira View Post
    A bury splice is actually stronger then a brummel lock splice. Because the lock puts shear stress on the line.
    Ha, a bury splice is so much easier and faster. Come to think of it you're right about it being stronger (when under tension). Is there any need to do a stitched whipping? That's mostly superficial, right?

    Simplified plan:

    1. Make a bury splice at one end of the DM20 rope around hub flange
    2. Engage the eye bolt 2 turns into the nipple on the rim, run the rope through the nipple, and pull taut.
    3. Make a bury splice as tightly as possible around the eyebolt and pull rope taut.

    I'm pretty optimistic about this, it might not take so long to actually do this.

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    The most annoying part of the splice is the taper. I have an idea to make that faster... so like a 15 degree cut with a 3d printed jig for a fast taper...

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    Here is the new drawing since the prior attachment looks broken.
    Added more thread length. I figured you can always cut it off if you're an advanced weight weanie. The extra gives more leeway for tensioning and tolerancing your splicing.
    Make your own polymer (UHMWPE) spokes?-capture.jpg
    Make your own polymer (UHMWPE) spokes?-capture2.png

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    So the point of the extra length is it for taking up more strain than steel? Or is for extra tolerance on spoke length? This is not a single-wall rim but you might get to a point where the threads are scratching through the rim strip.

    And meanwhile: how do you keep the spoke from twisting when you tension it? Do you have a certain spoke wrench in mind? Is there one that's like an end wrench, like the turnbuckle wrench that comes with R/C cars? I don't see how my Park wrench or a spokey would do it.

    On the splices: I still feel like you guys are making this harder because you want to be cleverer. If you make a loop, you can make a spoke that can be removed like a normal spoke and has one splice to do. Make two splices with one onto the hub and it can't. I'm sure that's why the Berd version has only one.

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    The extra length is for several reasons

    1.) the spoke do stretch more then steel, maybe 50%
    2.) there is also a small amount of viscoelastic stretch, hence need to retension after a day.
    3.) to account for rope settling and splice settling
    4.) to make it easier to get the length right

    If the threads are too long, and about to pierce the rim tape, you can always cut the end of the thread off.

    I am not sure that a loop is any easier then two eye splices. With a loop splice you have to do two buries anyway, which is the most annoying part. And it may be harder to get the length right. It may also be less aesthetically pleasing.
    One benefit would be that you can use 1mm line, and a much smaller hole would be needed in the eyebolt we're designing, making it possible to manufacturer from a 2.3/2.0 butted spoke (ie Sapim Strong)

    I ordered some Sapim Strong and Sapim 12g spokes to start testing making a pressed end eye bolt.

    Does anyone have a Hozan threader I can use? :-)

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    Quote Originally Posted by Darth Lefty View Post
    So the point of the extra length is it for taking up more strain than steel? Or is for extra tolerance on spoke length? This is not a single-wall rim but you might get to a point where the threads are scratching through the rim strip.

    And meanwhile: how do you keep the spoke from twisting when you tension it? Do you have a certain spoke wrench in mind? Is there one that's like an end wrench, like the turnbuckle wrench that comes with R/C cars? I don't see how my Park wrench or a spokey would do it.

    On the splices: I still feel like you guys are making this harder because you want to be cleverer. If you make a loop, you can make a spoke that can be removed like a normal spoke and has one splice to do. Make two splices with one onto the hub and it can't. I'm sure that's why the Berd version has only one.
    Yes you need to hold the end (eyebolt) to keep the rope from twisting. I used an open ended wrench and pliers. But it's better to use an external spoke wrench.

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    What about fishing knots? I recall the note in the other thread about knots pulling loose but there's a whole class of them that uses lots of friction from multiple wraps.

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    Quote Originally Posted by Darth Lefty View Post
    So the point of the extra length is it for taking up more strain than steel? Or is for extra tolerance on spoke length? This is not a single-wall rim but you might get to a point where the threads are scratching through the rim strip.
    Most carbon rims are at least 25mm deep, which amounts to the distance between the internal rim bed and the external rim bed being about 18-20mm, plus the nipple is another 10mm inside of the wheel compared to the internal rim bed, so you have at least 28m of usable distance in most carbon rims. This would not work for single-wall alloy rims, however (like my Mulefuts).

    I do think it's really important to have as much threaded length as is reasonable because it will be tricky getting precise tolerances.

    Quote Originally Posted by Darth Lefty View Post
    And meanwhile: how do you keep the spoke from twisting when you tension it? Do you have a certain spoke wrench in mind? Is there one that's like an end wrench, like the turnbuckle wrench that comes with R/C cars? I don't see how my Park wrench or a spokey would do it.
    Okashira is spot on.

    Quote Originally Posted by Darth Lefty View Post
    On the splices: I still feel like you guys are making this harder because you want to be cleverer. If you make a loop, you can make a spoke that can be removed like a normal spoke and has one splice to do. Make two splices with one onto the hub and it can't. I'm sure that's why the Berd version has only one.
    Again, Okashira is right on. You end up still having to introduce two splices, plus use thinner line (which can be broken or cut through more easily). You also have that "looks different" element, which I'm not a fan of. You lose that "aero" contour in the center of the spoke as well (not that it matters that much), plus you're going to end up using more rope total per spoke (by at least 1.5x).

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    Quote Originally Posted by Darth Lefty View Post
    What about fishing knots? I recall the note in the other thread about knots pulling loose but there's a whole class of them that uses lots of friction from multiple wraps.
    Knots can weaken the tensile strength of dyneema (and most ropes) by up to 70%. If we're using 2mm rope, this might not be a huge problem, but a simple splice looks like it will be almost as easy as tying a good knot once you get the process down, plus you don't decrease tensile strength.

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    I got my first official quote for eyebolts today, $1/piece in Grade 5 titanium. Rolled threads. Excludes shipping, tax, and payment fees, so probably more like $1.25 per piece all said and done.

    I think I'll get at least two much cheaper quotes in 7075 aluminum alloy, more like $0.10-$0.25/piece.

    7075 alloy is 36% lighter than Ti anyway. I know it's not as durable, but hey, we use alloy nipples.

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    Quote Originally Posted by Darth Lefty View Post
    What about fishing knots? I recall the note in the other thread about knots pulling loose but there's a whole class of them that uses lots of friction from multiple wraps.

    Tying a knot in 2mm uhmwpe doesn't work very well.

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    Quote Originally Posted by sissypants View Post
    I got my first official quote for eyebolts today, $1/piece in Grade 5 titanium. Rolled threads. Excludes shipping, tax, and payment fees, so probably more like $1.25 per piece all said and done.

    I think I'll get at least two much cheaper quotes in 7075 aluminum alloy, more like $0.10-$0.25/piece.

    7075 alloy is 36% lighter than Ti anyway. I know it's not as durable, but hey, we use alloy nipples.
    If you take the i9 spokes as an example, you will see they are much thicker and butted, don't think you will be able to get the eyebolt thick enough to keep them durable unless you use internal nipples also custom made.

  69. #69
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    Quote Originally Posted by Aglo View Post
    If you take the i9 spokes as an example, you will see they are much thicker and butted, don't think you will be able to get the eyebolt thick enough to keep them durable unless you use internal nipples also custom made.
    I have nothing against sourcing custom internal nipples and making wider bolts, but I'm not sure why the eyebolt needs to be thicker than 2mm if that works for normal spokes? Going above-and-beyond on a weight-weenie project is kind of counterintuitive.

    We will, on average, be engaging all of the nipple threads compared to typical wheel builds where only a few threads are engaged, on average.

  70. #70
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    So far $1/piece in Grade 5 titanium (MOQ 1000pcs) is my best quote, that's from Baoji Metals Ltd. I'm trying to get them to agree to a "test" batch of 150 pieces at that price.

    In 7075 alloy I have a quote from Dongguan Weimi Technology looking at $1.45/pc. for 1,000 pieces, $1.06/pc. for 2,000 pieces. Left-hand threads are rolled. Expensive! I'm trying to get them to $1.45/pc for 500 pieces or $1.06/pc. for 1,000 pieces.

    Eight other places turned me down right away because they only make bolts M3-M5 or larger, or because my MOQ was too small.

  71. #71
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    Quote Originally Posted by sissypants View Post
    I have nothing against sourcing custom internal nipples and making wider bolts, but I'm not sure why the eyebolt needs to be thicker than 2mm if that works for normal spokes?
    But it's not really about thread engagement, it's about the cross section at the thread minor diameter. Steel is much stronger at a given section. Aluminum spokes use bigger threads from what I can learn

  72. #72
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    Perhaps I've missed it here, but how are you going to get the eyebolt through the spoke hole? Assuming that you're going to affix it (and the threaded rod) to the spoke before lacing?

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    Quote Originally Posted by Darth Lefty View Post
    But it's not really about thread engagement, it's about the cross section at the thread minor diameter. Steel is much stronger at a given section. Aluminum spokes use bigger threads from what I can learn
    Yeah, you're right. Ti is best, but man this is getting expensive. I'm feeling my wallet and am hesitant to take on 1,000 Ti bolts.

    $1/bolt @ 1,000 pcs
    $14/100ft. DM20 rope
    $20 small rope puller/splicer

    The bolts make this investment pretty crazy considering I already have 4.3g Pillar X-tra Aero spokes and will only be dropping 100g on the wheelset.

    I can't decide...

    On the other hand, I have spokes laying around. Might as well cut them up and spear them into some rope for starters, then go from there.

  74. #74
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    Quote Originally Posted by mikesee View Post
    Perhaps I've missed it here, but how are you going to get the eyebolt through the spoke hole? Assuming that you're going to affix it (and the threaded rod) to the spoke before lacing?
    In the proposed system, the eyebolt fastens to the nipple, the spoke/rope is spliced through the eye of the eyebolt. At the hub, the spoke is spliced to either fasten like a Berd spoke with a small fragment of rope or is spliced directly into the hub.

    The eyebolt would never need to be pulled through the spoke hole because either 1) the hub side of the spoke is spliced directly onto the spoke, or 2) the splice on the hub side of the spoke can be shoved/pulled backwards through the spoke hole (spoke hole can be drilled bigger or beveled if need be).

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    I should have looked up the splices long before. I thought I needed to braid rope back on itself like I learned in Scouts 30 years ago when we made rope out of twine, and then forgot 29 years ago when I never did it again. But it's just grabbing the end and pulling it through. Gonna stop complaining about it now!

    I did note one website said to bury it 72 times its diameter for Dyneema. That's 5-1/2 inches for 2mm rope. Really?

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    How is wheel building going to go? Are we going to build a wheel with wire spokes and replace them one at a time? I guess there's a minimum wheel build you could do with six or eight spokes a side that would hold its shape before you go in and snug it all up

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    Quote Originally Posted by Darth Lefty View Post
    How is wheel building going to go? Are we going to build a wheel with wire spokes and replace them one at a time?
    I'm planning lacing the wheel width rope spokes from the start, I don't see the point of lacing them first with steel spokes.

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    Quote Originally Posted by sissypants View Post
    I have nothing against sourcing custom internal nipples and making wider bolts, but I'm not sure why the eyebolt needs to be thicker than 2mm if that works for normal spokes? Going above-and-beyond on a weight-weenie project is kind of counterintuitive.

    We will, on average, be engaging all of the nipple threads compared to typical wheel builds where only a few threads are engaged, on average.
    What Darth Lefty said.
    The i9 spokes aren't "super" thick at the thread and thicker than normal spokes in general to look cool, they have to be thicker than steel spokes to support the same tension.

  79. #79
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    I thought it might be easy to buy a box of steel 2-56 eye bolts just to try out the technique, but so far I can only find them in $3 4-packs with nuts, carded for hobby stores. I guess they aren't that standard. Seems like they bottom out at 6-32.

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    I will do one of my DT swiss x1700 first, then my new chinese rim. Have not started. Was still waiting on my DM20.

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    Rope finally came in
    Make your own polymer (UHMWPE) spokes?-mnvx9pe.jpg
    Make your own polymer (UHMWPE) spokes?-m2l2iex.jpg

    I 3d print this to help get nice clean cuts.
    I forgot to add another cut at like a 15 degree angle to make a fast taper.
    Make your own polymer (UHMWPE) spokes?-kznqrcc.jpg

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    yeah that may be overkill as long as you keep it tensioned.
    I think you an get away with 90mm = 3.6"

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    @sissypants
    some quick replies

    I think grade 5 titanium isn't strong enough. Needs to be an alloy.

    I think 304 ss aka 18-10 ss is a better starting point:
    Its inexpensive
    It cold works like a champ
    It's great with fatigue

    You can send the drawings I made to the suppliers....
    I can also ask some american companies.
    We can also consider a mini kickstarter to raise funds and distribute the eyebolts.

    let's do some prototyping first to make sure the design is even any good anyway.

    I really want to stick with 14ga because I have not seen 13ga or 12ga aluminum nipples
    and my Chinese rim is for 14g only!

  84. #84
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    Quote Originally Posted by okashira View Post
    I think grade 5 titanium isn't strong enough. Needs to be an alloy. I think 304 ss aka 18-10 ss is a better starting point
    304 ss is also nearly 3x heavier than 7075 alloy and still much heavier than grade 5 titanium. But we need something that works, so if you think it'll do I'm all for it!

    You're still getting a <1g weight calculation from your updated model for 304 ss, correct?

    You can send the drawings I made to the suppliers....
    Will do. It would be great if you ask some American companies as well.

    We can also consider a mini kickstarter to raise funds and distribute the eyebolts.
    Definitely, happy to help and happy to pledge, let me know how you want to do that. Send a PM if you want or just start something.

    I really want to stick with 14ga because I have not seen 13ga or 12ga aluminum nipples
    Sounds good.

    That 3D printed apparatus is sweet!

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    Quote Originally Posted by sissypants View Post
    I'm afraid that bending a spoke to make an eye would severely compromise the strength of the material and it might not hold, although I like the idea. It's not hard to bend a spoke, so unbending that wouldn't be too hard either.
    Circling back to this (heh heh) I remembered that Z-bend spokes were a thing. If those worked then so should a loop. If there's a sort of latch effect happening from how the Z bend loads up then we can make a latch behind our loop by wrapping it once back around. Not unlike this safety pin style, though I'm imagining a much shorter loop https://www.homedepot.com/p/Everbilt...5408/204276312

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    0.95G for the longer threads. You could cut it down the threads and it would be 0.83g.

    Make your own polymer (UHMWPE) spokes?-capture.jpg
    Make your own polymer (UHMWPE) spokes?-capture2.jpg

    If you want to do titanium, it has to be Ti 6Al-4V and heat treated, and then the threads rolled. Yes I think the Hozan threader could roll them.
    It would be iffy though. I am not sure titanium spokes use 14g. They might use 13g.
    Ti-6Q2 (Ti-62222s) might work, but I guarantee you the Chinese won't have that alloy. They will have 6Al-4V, though. It's very common.
    If we can find 13g aluminum nipples, i can redesign the part for 13g to beef it up a bit, and maybe the weight comes down to ~0.6-0.7g with 6Al-4V.
    Note the dyneema is like 1.1-1.2g total weight comes to like 2.1-2.2g with the dyneema and the longer 304ss end.

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    Quote Originally Posted by Darth Lefty View Post
    Circling back to this (heh heh) I remembered that Z-bend spokes were a thing. If those worked then so should a loop. If there's a sort of latch effect happening from how the Z bend loads up then we can make a latch behind our loop by wrapping it once back around. Not unlike this safety pin style, though I'm imagining a much shorter loop https://www.homedepot.com/p/Everbilt...5408/204276312
    I had to think for 3sec on what you were talking about with Z-bend .

    When I was talking about bending a spoke and braze it with brass I was referring to something like the picture bellow, the yellowish area is where the braze is made.

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  88. #88
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    Quote Originally Posted by okashira View Post
    0.95G for the longer threads. You could cut it down the threads and it would be 0.83g.

    Click image for larger version. 

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    (...)

    okashira do you think the 1.1mm thickness of the eye will be ok, will not this value cause too much stress on the fibers?

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    I thought 1.1 is ok for 1.8mm line, based on gut feeling. 0.8mm was not, that's why I made it thicker.
    We can test it.
    It does need to be nicely rounded.
    I can buy a 300kg scale and do some break testing with a wench.

    According to sampson , they say at least 3:1... which means we need 1.8*3 = 5.4mm! 4.5mm with a 1.5mm line

    But that's for safety applications with lots of movement of the eye. In our case, the eye will be pretty stationary, it's worth testing?

    Page 38:
    http://www.samsonrope.com/Documents/...Manual_WEB.pdf

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    Quote Originally Posted by sissypants View Post
    In the proposed system, the eyebolt fastens to the nipple, the spoke/rope is spliced through the eye of the eyebolt. At the hub, the spoke is spliced to either fasten like a Berd spoke with a small fragment of rope or is spliced directly into the hub.

    The eyebolt would never need to be pulled through the spoke hole because either 1) the hub side of the spoke is spliced directly onto the spoke, or 2) the splice on the hub side of the spoke can be shoved/pulled backwards through the spoke hole (spoke hole can be drilled bigger or beveled if need be).

    Huh. OK. Sounds needlessly complex.

    ...i say as i sit on the sidelines fascinated by where this is (potentially) going.

  91. #91
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    If we're gonna source parts custom, I will design a new part with better bend radius for the eye. If anyone finds a or knows of a 13g aluminum nipple, I can design one for 13g and titanium alloy. With ti alloy ends we could end up with really strong spokes at just 1.9g each, but wouldn't be worth it if there aren't any aluminum nipples like 14g.

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    Any theories what Berd's "customized coating" might be?

    I'm seeing why Berd have done it with a regular spoke end. They don't need to get the length of the string very precise if they're sliding it over a couple inches of spoke end.

    Do you suppose they have roughed up the spoke so the bury works better? or would that abrade the string

    On the other hand, windup: With the eye you will be able to use an end wrench on the nipple and put an Allen wrench through the eye, so you can use a regular nipple. With the spoke end you need to hold the spoke with pliers and do the nipple with a socket from the back of the rim.

    In the other weight-weenie direction from larger titanium, is smaller steel. What about using a 15g steel spoke and not a 2.0 at the outer end? Alloy nipples definitely available. It seems like they might get cycled less in strain due to the longer stretch of the Dyneema spreading it out... and the large MTB tire and stiff carbon rim doing a better job distributing the load among more spokes at a time.

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    Okashira, how did you con Marlow into selling you 1.8mm DM20 rope? This is really strange business. After several emails back and forth Nicole forwarded me to Chrissy (the boss) finally ended like this:

    "Unfortunately no, we are not able to sell to end users and a MOQ would still not allow us to do so. Again, I apologize for the inconvenience."

    They are unwilling to sell, at any price, at any amount. I offered to buy 10,000 meters of rope to meet any MOQ requirements.

    Maybe I should try emailing from my LLC account with my commercial signature.

  94. #94
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    Quote Originally Posted by Darth Lefty View Post
    Any theories what Berd's "customized coating" might be?
    I'm not sure where you read about this, but I googled it and found a Yahoo article stating the following:

    Berdís special spokes use a customized coating to increase resistance to wear and tear, abrasion, moisture, and UV exposure as well.
    Polyurethane (PU). 99% sure. Marlow offers PU treatment on a lot of their ropes. Subsequent heat treatment (referred to as HPC technology by some vendors) might also help.

    I'm seeing why Berd have done it with a regular spoke end. They don't need to get the length of the string very precise if they're sliding it over a couple inches of spoke end.
    That, and... it's cheap. Plus it doesn't look different.

    Do you suppose they have roughed up the spoke so the bury works better? or would that abrade the string
    Epoxy adhesive? It's probably a "customized coating" or "proprietary material".

    In the other weight-weenie direction from larger titanium, is smaller steel. What about using a 15g steel spoke and not a 2.0 at the outer end?
    I definitely like this idea of going smaller with a steel bolt. Okashira's take on durability? What kind of tension would this take?

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    Pm me I will give you contact

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    Quote Originally Posted by sissypants View Post
    I'm not sure where you read about this, but I googled it and found a Yahoo article stating the following:



    Polyurethane (PU). 99% sure. Marlow offers PU treatment on a lot of their ropes. Subsequent heat treatment (referred to as HPC technology by some vendors) might also help.



    That, and... it's cheap. Plus it doesn't look different.



    Epoxy adhesive? It's probably a "customized coating" or "proprietary material".



    I definitely like this idea of going smaller with a steel bolt. Okashira's take on durability? What kind of tension would this take?
    Marlow's 1.8mm DM20 is heat stretched and PU.

    On spoke tension, so titanium and/or 15ga steel might work best on wheels with 32,36,40 spokes. Where you can target like <70Kgf tension. Might be a good combo with 1.5mm line instead of 1.8.

    My wheels are 28 spoke so I will probably want a little more tension...

    PS I have a friend in town visiting so I won't have much time to work on this for next 5 days

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    Tweaked to lower mass.

    0.77g for 302ss
    0.424g for Ti Alloy

    Total spoke weight
    1.92g 302ss
    1.57g Ti

    Still using the 1.1mm thickness, we will do some testing to see if 1.1mm is okay or we need to make it thicker (~2mm)

    Make your own polymer (UHMWPE) spokes?-capture.png

  98. #98
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    may need a patent lawyer to verify you won't infringe on Berd patent if you intend to sell

    SPOKE COMPOSED OF BRAIDED FIBER WITH HUB AND RIM TERMINATIONS


    of course, keep building it,

    maybe not sell any, till the all clear is vetted
    "Put your seatbelt back on or get out and sit in the middle of that circle of death." - Johnny Scoot

  99. #99
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    Quote Originally Posted by 127.0.0.1 View Post
    may need a patent lawyer to verify you won't infringe on Berd patent if you intend to sell

    SPOKE COMPOSED OF BRAIDED FIBER WITH HUB AND RIM TERMINATIONS


    of course, keep building it,

    maybe not sell any, till the all clear is vetted
    If he is potentially in violation selling or not selling won't necessarily be protection. Not selling would probably reduce damage liabilities though.

    Sent from my SM-N950U using Tapatalk

  100. #100
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    Quote Originally Posted by tuckerjt07 View Post
    If he is potentially in violation selling or not selling won't necessarily be protection. Not selling would probably reduce damage liabilities though.

    Sent from my SM-N950U using Tapatalk
    Oh cmmon, this is a DIY project If it ever would hit the market it would be because it is so different from Berd that it makes sense to market it.

    I wouldn't market until I could improve on the hub interface and materials used. My chemistry background is coming in handy DM20 isn't the only material out there like this.

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