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  1. #201
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    Quote Originally Posted by robbnj View Post
    I did read it. My takeaway (based on his statement - I am not an engineer) is that a reduction of tension DOES increase lateral flexibility, but the deflection is not significant when dealing with very light lateral loads (25 pounds) as seen on a road bike.

    He only used 25 pounds in order to show deflection occurs, but he was afraid to damage a wheel by using more weight than that.

    I wonder what kind of lateral load a 200lb rider exerts on an MTB wheel when cornering hard at a reasonable speed? I'd have to guess it's more than 25 pounds? My bike weights about 26 pounds. I would think that just standing it at a 45 degree angle would put about 6 pounds lateral load on each wheel (25lbs/2 wheels=12.5, 12.5/2 to account for the 45 angle= 6 lbs)

    Perhaps on a road wheel that sees little to no lateral stress spoke tension has little importance, but on an MTB wheel that sees high lateral loads, it would be far more important?
    <making sure I'm not in a road bike discussion as I type this>

    Attachment 1227652
    I have to ask, based on your example:

    Why would an MTB rider on a BERM exert a higher lateral load on a wheel than a road rider going 50mph down a road? Given that a road tire has far, far higher amounts of traction on pavement than an MTB tire does on loose dirt, I have a hard time imagining that, short of casing a jump, you'd ever impart as much lateral force into an MTB wheel as you would a road wheel.

    Also, below is Damon Rinard's statement from that article re: spoke tension. Until a wheel goes completely slack, there is no difference in lateral wheel stiffness, as he clearly says. Bolded text by me.

    "Some believe that a wheel built with tighter spokes is stiffer. It is not. Wheel stiffness does not vary significantly with spoke tension unless a spoke becomes totally slack.

    I measured the deflection of Wheel #2 while gradually loosening the spokes in quarter turn increments. The wheel did not display any significant change in stiffness until the spokes were so loose some became totally slack.

    If the spokes are so loose that some become slack, the wheel becomes much more flexible. The last two data points below, 9 and 10, taken when the spokes were so loose the wheel was almost sloppy, show that the wheel becomes significantly more flexible when spokes on the detensioning side of the wheel actually become slack. That is expected: a slack spoke cannot add stiffness to the wheel; it buckles easily in compression.

    A wheel whose spokes become slack while riding is a weak wheel, because slack spokes cannot support the rim. This can be avoided to a large extent by building wheels with tighter spokes. If spokes are tighter initially, then the sudden increase in flexibility shown in data points 9 and 10 is less likely to occur in use because a tighter wheel can bear a higher load before spokes become slack."

    The last part, italicized by me, relates to wheel strength (re: durability), and has nothing to do with lateral stiffness.

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  2. #202
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    Quote Originally Posted by Le Duke View Post
    I have to ask, based on your example:

    Why would an MTB rider on a BERM exert a higher lateral load on a wheel than a road rider going 50mph down a road? Given that a road tire has far, far higher amounts of traction on pavement than an MTB tire does on loose dirt, I have a hard time imagining that, short of casing a jump, you'd ever impart as much lateral force into an MTB wheel as you would a road wheel.
    The key is LATERAL load. Going straight down a road produces RADIAL load, but almost no lateral load. The author himself says so. Cornering is where the lateral load comes into play.

    Also, below is Damon Rinard's statement from that article re: spoke tension. Until a wheel goes completely slack, there is no difference in lateral wheel stiffness, as he clearly says. Bolded text by me.
    So, once deflection occurs due to spoke tension being reduced, it doesn't increase as tension is reduced more by unthreading the spoke. This could make sense as any change would likely be VERY hard to measure (how much movement occurs with a quarter turn of a spoke nipple?), but his own chart shows different.
    "Some believe that a wheel built with tighter spokes is stiffer. It is not. Wheel stiffness does not vary significantly with spoke tension unless a spoke becomes totally slack.
    Yet, the chart he provides shows a change with every turn. The change may be insignificant under an insignificant load, but I don;t think the loads caused by MTBers would be insignificant (maybe they are? maybe hard cornering indices no lateral stress on an MTB wheel?)

    I measured the deflection of Wheel #2 while gradually loosening the spokes in quarter turn increments. The wheel did not display any significant change in stiffness until the spokes were so loose some became totally slack.

    If the spokes are so loose that some become slack, the wheel becomes much more flexible. The last two data points below, 9 and 10, taken when the spokes were so loose the wheel was almost sloppy, show that the wheel becomes significantly more flexible when spokes on the detensioning side of the wheel actually become slack. That is expected: a slack spoke cannot add stiffness to the wheel; it buckles easily in compression.

    A wheel whose spokes become slack while riding is a weak wheel, because slack spokes cannot support the rim. This can be avoided to a large extent by building wheels with tighter spokes. If spokes are tighter initially, then the sudden increase in flexibility shown in data points 9 and 10 is less likely to occur in use because a tighter wheel can bear a higher load before spokes become slack."
    This sounds odd to me. I always understood that the hub "hangs from the rim", as opposed to being "supported by the spokes". If spokes are all equally loose, but still attached, can't you still roll down the path (at least in a straight line)?

    I'm thinking we may be talking in two different paths here. Are you leaning toward the idea of SIGNIFICANT lateral deflection (as defined by the rather unscientific test in your link) as opposed to your statement that there is NO deflection when spokes are loosened?
    Would you hop on an MTB that had all spokes detensioned to the point just before they are slack, and bomb a trail with it?

  3. #203
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    Quote Originally Posted by robbnj View Post
    The key is LATERAL load. Going straight down a road produces RADIAL load, but almost no lateral load. The author himself says so. Cornering is where the lateral load comes into play.


    So, once deflection occurs due to spoke tension being reduced, it doesn't increase as tension is reduced more by unthreading the spoke. This could make sense as any change would likely be VERY hard to measure (how much movement occurs with a quarter turn of a spoke nipple?), but his own chart shows different.
    Yet, the chart he provides shows a change with every turn. The change may be insignificant under an insignificant load, but I don;t think the loads caused by MTBers would be insignificant (maybe they are? maybe hard cornering indices no lateral stress on an MTB wheel?)


    This sounds odd to me. I always understood that the hub "hangs from the rim", as opposed to being "supported by the spokes". If spokes are all equally loose, but still attached, can't you still roll down the path (at least in a straight line)?

    I'm thinking we may be talking in two different paths here. Are you leaning toward the idea of SIGNIFICANT lateral deflection (as defined by the rather unscientific test in your link) as opposed to your statement that there is NO deflection when spokes are loosened?
    Would you hop on an MTB that had all spokes detensioned to the point just before they are slack, and bomb a trail with it?
    My point, which I did not explain well enough, is that cornering at 50mph+ and no loss of traction is going to exert more lateral load than cornering at 30mph on loose terrain, or 30mph on a berm.

    The chart shows the exact opposite of what you think it does. Note that the Y-axis is DEFLECTION IN INCHES. In this case, more is bad, and less is good. And, as the spokes are loosening, as you go from left to right on the X-axis, DEFLECTION is actually decreasing very slightly, until you get past the 8th quarter turn. Which means that the wheel was actually getting STIFFER, laterally. As the data table right next to that chart shows, deflection is actually decreasing, from the first quarter turn to the eighth quarter turn.

    No, I wouldn't hop on an MTB with detensioned spokes, because it would be a very weak wheel, and I'd break spokes, and maybe the rim at some point.
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  4. #204
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    Bikes make coordinated turns. The only time your wheel gets a lateral load of any significance is when you crash, or if you hop up and down on the side of it like freestyle BMX, or if you corner like Marc Marquez. Can we get back to the Dyneema?

  5. #205
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    Quote Originally Posted by Darth Lefty View Post
    Bikes make coordinated turns. The only time your wheel gets a lateral load of any significance is when you crash, or if you hop up and down on the side of it like freestyle BMX, or if you corner like Marc Marquez. Can we get back to the Dyneema?

    Um, on a berm during a turn where the berm angle perfectly aligns with the resultant force, would be the only place this would be correct? That's the only way you could make a "coordinated" turn. Otherwise, you are implying a significant side-loading force when you turn, seems that this could be pretty easily drawn out in a force diagram.
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  6. #206
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    Quote Originally Posted by Darth Lefty View Post
    Bikes make coordinated turns. The only time your wheel gets a lateral load of any significance is when you crash, or if you hop up and down on the side of it like freestyle BMX, or if you corner like Marc Marquez. Can we get back to the Dyneema?
    Horsecrap, and I (on a Foxy 29) and the entire SB130/ 150 forums have the rub marks on the inside of our chain stays to prove it.

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  7. #207
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    If you are having wheel stiffness issues, why not use thicker spokes?




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  8. #208
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    I'm back in town and the 1.25 DM20 from Armare is here.
    Perhaps I should ask if they can do some 1.8, on a group buy?

    Make your own polymer (UHMWPE) spokes?-0fiuvkq.jpg
    Make your own polymer (UHMWPE) spokes?-8xjxurk.jpg
    Make your own polymer (UHMWPE) spokes?-wg1r8v5.jpg

  9. #209
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    Sweet! So at 40h that will do about eight wheels, is my math right?

  10. #210
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    Quote Originally Posted by Jayem View Post
    Um, on a berm during a turn where the berm angle perfectly aligns with the resultant force, would be the only place this would be correct? That's the only way you could make a "coordinated" turn. Otherwise, you are implying a significant side-loading force when you turn, seems that this could be pretty easily drawn out in a force diagram.
    The tire gets a lateral load, but it's reacted on the rim. The lean of the bike takes care of the resulting force through the plane of the frame and wheels. The angle is the arctangent of gravity and yaw, that's what I mean by coordinated. Compare the situation to a spoked car wheel for a counter example where you feel the yaw and the wheel DOES get a lot of side force.

  11. #211
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    deleteme

  12. #212
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    I just bought 100m of 1.5mm SK99 from Armare. Sent them an email asking to change to 1.5mm DM20. I'll post updates as they arrive.
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  13. #213
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    Scanning through the thread again.
    Regarding the methods of connecting to the hub & rim and being able to adjust tension: What about incorporating a miniature turnbuckle instead of trying to mimic the threaded nipple and shaft of the spoke?
    One end of the turnbuckle secures to the rim, the rope is looped and "chinese finger-trapped" through the eyelets on the 'buckles, and through the holes in the hub (which would have to be radiused to not cut through the rope). No need to secure hardware to the rope, and you get a wider range of adjustment (I think).

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  14. #214
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    Quote Originally Posted by robbnj View Post
    Scanning through the thread again.
    Regarding the methods of connecting to the hub & rim and being able to adjust tension: What about incorporating a miniature turnbuckle instead of trying to mimic the threaded nipple and shaft of the spoke?
    One end of the turnbuckle secures to the rim, the rope is looped and "chinese finger-trapped" through the eyelets on the 'buckles, and through the holes in the hub (which would have to be radiused to not cut through the rope). No need to secure hardware to the rope, and you get a wider range of adjustment (I think).

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    Very cool idea, I had the same thought but never posted up about it because for one these are a bit (a lot) heavier, they are also more expensive, and arguably more challenging to make durable at the weights we are trying to achieve. There's just no way a turnbuckle could be had for under 3/4 of a gram. Kinda defeats the purpose.

  15. #215
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    What function does that add vs a screw eye and standard spoke nipple?

  16. #216
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    Quote Originally Posted by Darth Lefty View Post
    Sweet! So at 40h that will do about eight wheels, is my math right?
    Pretty close. Too bad it seems to be hard to find lightweight hubs in 36 or 40h. Know any?

  17. #217
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    Quote Originally Posted by robbnj View Post
    Scanning through the thread again.
    Regarding the methods of connecting to the hub & rim and being able to adjust tension: What about incorporating a miniature turnbuckle instead of trying to mimic the threaded nipple and shaft of the spoke?
    One end of the turnbuckle secures to the rim, the rope is looped and "chinese finger-trapped" through the eyelets on the 'buckles, and through the holes in the hub (which would have to be radiused to not cut through the rope). No need to secure hardware to the rope, and you get a wider range of adjustment (I think).

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    It's a fine idea. Just too heavy.

  18. #218
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    Quote Originally Posted by Darth Lefty View Post
    What function does that add vs a screw eye and standard spoke nipple?

    I had read that looping the rope and "finger-trapping" it into itself (like sailors do) would be easier stronger than trying to secure the rope to a threaded rod.
    With 'buckles, there would only be the necessity to attach the rope to itself (i.e. stronger setup).

    I figured micro turnbuckles would be quite light, maybe just slightly heavier than the rod/nipple and screw eye setup, but a reasonable tradeoff for the strength and simplicity it would give.

  19. #219
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    Okashira,

    Think 1.5mm DM would be sufficient for a 28 spoke wheel (carbon rim)? 143lb rider, 120mm bike.

    Sent my email to Armare at 11:48am MST yesterday. No response yet. Hoping they'll get back to me today re: the SK99 to DM20 change.

    Update:

    Just got an email from Irene at Armare. They only make/sell 1.25 and 2.0mm DM20. Went with the 2.0mm material. I have no concerns about running 28h hubs now. I'm interested to see what the rated breaking load is on the 2mm DM20.

    Any reason not to go with the Brummel/Bury?

    https://www.animatedknots.com/brummeldemo/index.php
    Last edited by Le Duke; 1 Week Ago at 08:54 AM.
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  20. #220
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    Also, did you pay VAT from Italy to the US? I was charged 20.99E VAT...
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  21. #221
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    Quote Originally Posted by Suns_PSD View Post
    Horsecrap, and I (on a Foxy 29) and the entire SB130/ 150 forums have the rub marks on the inside of our chain stays to prove it.

    Sent from my SM-G892A using Tapatalk
    And let's not forget the lateral load placed just due to pedaling (isn't that why spoke tensions are different on opposites sides of the hub?)...

  22. #222
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    Quote Originally Posted by robbnj View Post
    And let's not forget the lateral load placed just due to pedaling (isn't that why spoke tensions are different on opposites sides of the hub?)...
    No, that's mostly related to hub geometry.
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  23. #223
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    The DM20 in 2.0mm is rated at 558 daN. Or, 569 kgf. Whoa.
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  24. #224
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    ...yes, to make room for the sprockets. Every few years the cluster gets wide enough they had to make the hubs wider or else the drive side spokes get too close to vertical (120->126->130 for 5, 6, 8 speed). That's one reason Boost and offset rims are good, to even up the angle, and it's one that's weirdly not first mentioned as they go on about chain stay length which seems like more of a stretch. It's also why Santana the tandem company went to a QR160 rear hub. They have some good figures about it on their website. https://santanatandem.com/wheel-tech

    Okashira, I don't know of any super light 40h hubs. Speaking of tandems, most such things I know of are for less fancy / more "normal" tandem bikes. I suppose an average hub could be drilled 40h as long as the flange is large enough, if you could ask them to do it.

  25. #225
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    Quote Originally Posted by Le Duke View Post
    No, that's mostly related to hub geometry.
    To dish the assembly?

  26. #226
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    Quote Originally Posted by robbnj View Post
    To dish the assembly?
    As hubs get wider and the bracing angles (with spokes, between the hub flanges and rim) get closer to being equal, spoke tensions can be closer to equal as well.
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  27. #227
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    Quote Originally Posted by Le Duke View Post
    Okashira,

    Think 1.5mm DM would be sufficient for a 28 spoke wheel (carbon rim)? 143lb rider, 120mm bike.

    Sent my email to Armare at 11:48am MST yesterday. No response yet. Hoping they'll get back to me today re: the SK99 to DM20 change.

    Update:

    Just got an email from Irene at Armare. They only make/sell 1.25 and 2.0mm DM20. Went with the 2.0mm material. I have no concerns about running 28h hubs now. I'm interested to see what the rated breaking load is on the 2mm DM20.

    Any reason not to go with the Brummel/Bury?

    https://www.animatedknots.com/brummeldemo/index.php
    Brummel is okay. It just takes longer then a simple bury.
    I think Brummel is a good choice.
    Yes I was charged VAT, and I asked about removing VAT, and they would not remove it.

  28. #228
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    Quote Originally Posted by okashira View Post
    Brummel is okay. It just takes longer then a simple bury.
    I think Brummel is a good choice.
    Yes I was charged VAT, and I asked about removing VAT, and they would not remove it.
    Likewise.

    They also added 40 Euro + for the upgrade from 1.5 SK99 to 2.0 DM20.

    All in, pretty expensive. But, I’ll have enough for quite a few wheels.


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  29. #229
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    Updates...

    1.) I got a call from local Ti company, they have some quotes for me on forged eye screws. I need to call them Monday.

    2.) Had some time over past couple days, here is where I am at.
    I decided to undo the ones I had made, and swap them around. The reason is the straight pull hubs are counterbored one one side. With spliced spokes, you will want the rope coming OUT of the counterbored side, because it will sit on a sharp edge if you go the normal way.
    So I am swapping them in pairs.
    My question is, is this okay? Will is mess up the crossing method?
    See the 3rd picture with the blue arrows to show what I mean. Those two have already been swapped.
    The one X'd in red is one I need to remove and swap to the opposite direction.
    Make your own polymer (UHMWPE) spokes?-t8960hz.jpg
    Make your own polymer (UHMWPE) spokes?-p841iw0.jpg
    Make your own polymer (UHMWPE) spokes?-vykw7wb.jpg

    3.) Random notes.... Buy regular j-bend hubs for these spokes. Much simpler and cleaner.
    I might need some help getting them laced int he 3cross method correctly again, lol. Assuming I didn't mess everything up by swapping the spoke directions.

    4.) The Chinese machine shop sissypants got a quote from completely ignored me after I sent them drawings and 3d models. Not cool on their part.
    I got another manufacturing contact while I was in Shanghai I need to follow up on.

  30. #230
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    Quote Originally Posted by okashira View Post
    The Chinese machine shop sissypants got a quote from completely ignored me after I sent them drawings and 3d models. Not cool on their part.
    Not cool, I'll try get back in touch with them on Alibaba. When you do it on Alibaba they want to get a high response rate so it's in their interest to reply. Plus, they pay for every lead on Alibaba.

  31. #231
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    This thread is soooo awesome!

    I'm in for group orders on fiber, eye screws and what-not. I really want someone to build a wheelset for me, though.

    Quote Originally Posted by okashira View Post
    Updates...

    1.) I got a call from local Ti company, they have some quotes for me on forged eye screws. I need to call them Monday.
    ...
    3.) Random notes.... Buy regular j-bend hubs for these spokes. Much simpler and cleaner.
    I might need some help getting them laced int he 3cross method correctly again, lol. Assuming I didn't mess everything up by swapping the spoke directions.

    4.) The Chinese machine shop sissypants got a quote from completely ignored me after I sent them drawings and 3d models. Not cool on their part.
    I got another manufacturing contact while I was in Shanghai I need to follow up on.
    (Sheeeett.. I think you just did some engineering for them!
    Maybe send old prelim drawings and models to Chinese shops get a quote?)

  32. #232
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    Another quick question re: Brummel.

    Obviously you aren't relying on the bury method for the loop, but still using a bury with the remaining material after the Brummel lock. How much material should you have in the short end that you bury in the main strand?

    I'm guessing the 72x is not necessary here, maybe not even half of that. Is there any recommendation on how much material to bury after the Brummel? 20x? 30x?
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  33. #233
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    Quote Originally Posted by Le Duke View Post

    The last part, italicized by me, relates to wheel strength (re: durability), and has nothing to do with lateral stiffness.

    Sent from my iPhone using Tapatalk
    I wouldn't waste too much time on it. We have people posting confidently on this forum who literally cannot interpret a basic stress-strain graph that is taught to every first year engineering student. They've been thinking the wrong way for so long that they just cannot be helped.

  34. #234
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    Quote Originally Posted by Le Duke View Post
    Another quick question re: Brummel.

    Obviously you aren't relying on the bury method for the loop, but still using a bury with the remaining material after the Brummel lock. How much material should you have in the short end that you bury in the main strand?

    I'm guessing the 72x is not necessary here, maybe not even half of that. Is there any recommendation on how much material to bury after the Brummel? 20x? 30x?
    With the brummel, the bury is still meant to take the load. The lock is just there to prevent slippage under no load or handling. (This is a very useful thing for a spoke, to keep the length from slipping!)
    You can maybe do 45x-50x. 20x, no way.

  35. #235
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    Quote Originally Posted by okashira View Post
    With the brummel, the bury is still meant to take the load. The lock is just there to prevent slippage under no load or handling. (This is a very useful thing for a spoke, to keep the length from slipping!)
    You can maybe do 45x-50x. 20x, no way.
    Cool. Just trying to get an idea of how much material I’d be looking at for a given length of spoke.

    How long were your titanium end pieces? I already have a Hozan thread roller (used it today on a CX-Ray from Germany that was 3mm too long).




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  36. #236
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    Quote Originally Posted by Le Duke View Post
    Cool. Just trying to get an idea of how much material I’d be looking at for a given length of spoke.

    How long were your titanium end pieces? I already have a Hozan thread roller (used it today on a CX-Ray from Germany that was 3mm too long).




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    Long enough to make 3 spoke ends per piece.
    I cut them 73mm long.

  37. #237
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    One side done.
    Looking at the inside of the hub, it appears that the inner splice tends to wrap around this sharp corner point on the DT 350. I am not sure if I rounded them all very well here. We will see what happens.
    It's definitely better to start from scratch so you have room to dremel off all the appropriate the sharp edges. It was a pain doing it in place.
    Make your own polymer (UHMWPE) spokes?-img_20181209_173902.jpg
    Make your own polymer (UHMWPE) spokes?-img_20181209_173906.jpg
    Make your own polymer (UHMWPE) spokes?-img_20181209_173917.jpg

  38. #238
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    Quote Originally Posted by okashira View Post
    One side done.
    Looking at the inside of the hub, it appears that the inner splice tends to wrap around this sharp corner point on the DT 350. I am not sure if I rounded them all very well here. We will see what happens.
    It's definitely better to start from scratch so you have room to dremel off all the appropriate the sharp edges. It was a pain doing it in place.
    Click image for larger version. 

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    That looks great! Great attention to detail and patience.

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  39. #239
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    Quote from local Ti company.
    They decided to quote the bent and spot welded version @ qty 500 and 1000

    About $4.61 each in qty 1000. Could be worse. Still cheaper then full on high end Ti spokes. Hah.
    If it were 10,000, it may come down to $3.00 at the minimum is my guess.

    I asked them to pursue a forging and to give me feed back on feasibility and to quote 5,000, 10,000, 20,000 units, as well as tooling costs.

  40. #240
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    Quote Originally Posted by Le Duke View Post
    The DM20 in 2.0mm is rated at 558 daN. Or, 569 kgf. Whoa.
    How many spokes will you run? 32, 36?
    I would have been tempted to go with 1.5.
    Maybe I should try to build my other X1700 with the 1.25 line and see how it holds up.
    The downside is the 1.5 will be pretty flexible (but nice damping/softer ride)

    With your 2.0 keep in mine you will need to have a slightly longer bury... maybe use 76mm long Ti ends.
    I have been running about 60-70mm of bury (too short) on my splices, I will report how they hold up once I finish and ride with this damn wheel.

    Note I have been designing the eye bolts for 1.8mm line, with 2.0mm hole. It might be difficult to use the 2.0mm hole with 2.0mm line.

  41. #241
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    Quote Originally Posted by Darth Lefty View Post
    ...yes, to make room for the sprockets. Every few years the cluster gets wide enough they had to make the hubs wider or else the drive side spokes get too close to vertical (120->126->130 for 5, 6, 8 speed). That's one reason Boost and offset rims are good, to even up the angle, and it's one that's weirdly not first mentioned as they go on about chain stay length which seems like more of a stretch. It's also why Santana the tandem company went to a QR160 rear hub. They have some good figures about it on their website. https://santanatandem.com/wheel-tech

    Okashira, I don't know of any super light 40h hubs. Speaking of tandems, most such things I know of are for less fancy / more "normal" tandem bikes. I suppose an average hub could be drilled 40h as long as the flange is large enough, if you could ask them to do it.
    You're right.. With 36h or 40h, you could drill smaller holes for 1.5 or 1.25mm line. No need for the typical 2.5mm hole. Could easily fit 36 or 40H on a typical hub.

  42. #242
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    You guys are killing it.

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  43. #243
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    Quote Originally Posted by okashira View Post
    How many spokes will you run? 32, 36?
    I would have been tempted to go with 1.5.
    Maybe I should try to build my other X1700 with the 1.25 line and see how it holds up.
    The downside is the 1.5 will be pretty flexible (but nice damping/softer ride)

    With your 2.0 keep in mine you will need to have a slightly longer bury... maybe use 76mm long Ti ends.
    I have been running about 60-70mm of bury (too short) on my splices, I will report how they hold up once I finish and ride with this damn wheel.

    Note I have been designing the eye bolts for 1.8mm line, with 2.0mm hole. It might be difficult to use the 2.0mm hole with 2.0mm line.
    Well, I'm not sure just yet.

    I've got a spare DT Swiss 180 28h hub hanging around here, but no rim for it. I'm a little concerned that I'd be treading in unknown water, though, by going for 28h right out of the gate.

    But, as I said, I'm 143lbs, riding a 120/100mm bike, and prefer to skip over the top of rocks rather than plow. So, I'm guessing/hoping that the 2mm DM20 will provide the ride I'm looking for.
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  44. #244
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    So how are you measuring tension? I suppose it's possible to do the math on the elasticity and get a reasonable guess what you'd see on a tensiometer

  45. #245
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    So, here's my plan.

    I'm going to install a single spoke on a wheel that I already have built and tensioned at 110kgf. I'll bring it up to tension, then check it and tighten it a couple of times over the course of a couple days as necessary to bring it back up to tension/true. Maybe a couple, just to be safe. Two on each side of a wheel, for example.

    Then, I'm going to pluck that spoke like you would a string on a bass or guitar, and compare that to the notes on a tone generator app on my phone. If I can match that to a tone/frequency, I'll know that B flat (just an example) is 90kgf, and E is 110kgf. Sounds crazy, I know, but it should work.
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  46. #246
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    Quote Originally Posted by Le Duke View Post
    So, here's my plan.

    I'm going to install a single spoke on a wheel that I already have built and tensioned at 110kgf. I'll bring it up to tension, then check it and tighten it a couple of times over the course of a couple days as necessary to bring it back up to tension/true. Maybe a couple, just to be safe. Two on each side of a wheel, for example.

    Then, I'm going to pluck that spoke like you would a string on a bass or guitar, and compare that to the notes on a tone generator app on my phone. If I can match that to a tone/frequency, I'll know that B flat (just an example) is 90kgf, and E is 110kgf. Sounds crazy, I know, but it should work.
    I'm not sure the resolution of the tone frequency will be sufficient to tension to tolerances you want. It's an experiment though, I'll be very curious to see the data

    I have perfect pitch. Imagine tensioning a wheel to extreme precision without a tensiometer

  47. #247
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    Quote Originally Posted by sissypants View Post
    I'm not sure the resolution of the tone frequency will be sufficient to tension to tolerances you want. It's an experiment though, I'll be very curious to see the data

    I have perfect pitch. Imagine tensioning a wheel to extreme precision without a tensiometer
    FWIW, I don't even own a tensiometer. Never have. I've borrowed one a couple of times to check my own work building wheels, but that's it. A finely tuned ear and fingers have been sufficient to get a wheel into riding condition, and the tensiometer just confirms things.
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  48. #248
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    Quote Originally Posted by Le Duke View Post
    So, here's my plan.

    I'm going to install a single spoke on a wheel that I already have built and tensioned at 110kgf. I'll bring it up to tension, then check it and tighten it a couple of times over the course of a couple days as necessary to bring it back up to tension/true. Maybe a couple, just to be safe. Two on each side of a wheel, for example.

    Then, I'm going to pluck that spoke like you would a string on a bass or guitar, and compare that to the notes on a tone generator app on my phone. If I can match that to a tone/frequency, I'll know that B flat (just an example) is 90kgf, and E is 110kgf. Sounds crazy, I know, but it should work.
    If you think that the plucked frequency of the polymer spoke should be the same as the stainless spoke for same tension, you would be wrong. Better to do one spoke at a time and the trueness of the wheel would determine the correct tension.

  49. #249
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    Make your own polymer (UHMWPE) spokes?

    Quote Originally Posted by MikeDee View Post
    If you think that the plucked frequency of the polymer spoke should be the same as the stainless spoke for same tension, you would be wrong. Better to do one spoke at a time and the trueness of the wheel would determine the correct tension.
    Did you even read my post?

    I didn’t say anything about plucking a steel spoke. At all.

    I’d bring the polymer spoke up to tension (meaning, the wheel back to true), then determine its frequency once it settled at the same number of kgf as the others on the same side. This is the “install a single spoke” portion of the post you quoted. I am very clearly talking about a single polymer spoke here, given the very specific nature of this thread.

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  50. #250
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    It would be easier to get a $30 300kg scale and tighten the spoke to a measured value, then pluck and correlate freq with tension.

  51. #251
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    Quote Originally Posted by Schulze View Post
    It would be easier to get a $30 300kg scale and tighten the spoke to a measured value, then pluck and correlate freq with tension.
    Ah. Nice idea. Thanks!






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  52. #252
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    Nice job on the lacing and building! This is a great thread.
    "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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  53. #253
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    The empirical approach is ok but there are four different spoke tensions on a modern MTB thanks to dishes on both ends. I'd rather make data. But I'm wondering if there will be room to measure with a Park tensiometer between the 3" long spoke end, and the crosses. I'll see if I can work out the distension tomorrow if I have a boring lunch. I looked up Spox tensiometer recommendations and they weren't out of line with normal spokes, these shouldn't be either.

  54. #254
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    I think they will read a lower tension on a meter.
    if you want to use natural frequency to determine tension, keep in mind the crossing point where it contacts another spoke, this will affect the length and the natural frequency of the spoke, which is a function of length.

  55. #255
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    Yes, they have no baseline bending strength like a round steel spoke so there's only the tension. It'll be like Spox or like bladed spokes which are all on the upper end of the chart.

    I have some confusion. The TM-1 chart lists Spinergy SPO at 2.6mm, Spinergy's website lists SPOX at 3mm. Are these different products?

  56. #256
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    each hand-made braided spoke will have slight differences... frequency tuning each one would not be as accurate as say, frequency tuning set of very identical metal spokes. each braided spoke under same exact tension might 'tune' differently...perhaps the differences are statistical noise and you can accurately tension with a chromatic tuner

    I would imagine slapping a snark on the rim and plucking away, and tuning all spokes to (some setting on the snark) will be pretty close.

    or maybe this would be a good way for field testing how the spoke tension is doing over time vs initial build

    they are cheap

    https://www.amazon.com/Snark-Instrum.../dp/B003VWKPHC
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  57. #257
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    I am finished except the last couple, waiting on replacement nipples
    Make your own polymer (UHMWPE) spokes?-5tuhtur.jpg
    Make your own polymer (UHMWPE) spokes?-6dochb1.jpg

  58. #258
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    Wow! That's cool.

    I've been playing around with the idea of a conversion factor for the Park TM-1 today and I'm just not satisfied. The tool has a few compromises in its design that make the properties of the spoke (diameter, stiffness) part of the result and it adds tension while you use it. That's why the card included just has an individual listing for each most popular type of spoke and no approach to other oddballs. Reasonable just to do the calibration with a load cell as suggested above.

  59. #259
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    I think a sub 400g front XC wheel is possible. Eyeing a prince front hub and, carbonfan XC rim to build one just for the accomplishment.
    Will needs some Ti eyebolts....

    I'm eager to test this x1700. I'm concerned about a few things .. I built it with a few niggles...

    Too short burys on some of the splices.

    Concerned about the short burys on the Ti ends (I'm amazed Berd gets away with it)

    Concerned about the threading on the Ti rods. I think the rods are cold worked and very brittle.
    They should probably be stress relived or even annealed before threading but I decided to try it anyway. I did have issue threading some of them and you could see some chipping / cracking coming from the tread rolling process.
    The issue is stress relieve or annealing would require heat treatment in an inert atmosphere which could be done economaclly.... in bulk.

  60. #260
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    Quote Originally Posted by okashira View Post
    I think a sub 400g front XC wheel is possible. Eyeing a prince front hub and, carbonfan XC rim to build one just for the accomplishment.
    Will needs some Ti eyebolts....
    If you're going for the record, I would suggest Extralite Hyperboost (front 78g), Tune Prince is heavier (89g for 6-bolt blinged-out Skyline CeramicSpeed). I have also heard a few positive long-term reviews of Hyperboost, not so much of the Tune Prince series.

    https://fairwheelbikes.com/extralite...isc-front-hub/

    Carbonfan makes great rims, you may want to see if they can do a T800/T1000 special order to further reduce the weight. I own these BTLOS rims and they weigh 279g and 282g:

    https://btlos.com/mountain-bike/cros...ter=1%2C6%2C34

    BTLOS is usually willing to do custom manufacturing as well at very affordable prices:

    Assuming you use 24 spokes and the spokes are 1.6g/ea. and the nipples are 0.32g ea. you're looking at:

    Rim: 280g
    Spokes: 38.5g (1.6g * 24)
    Nipples: 8g (0.32g * 24)
    Hub: 78g
    Total: 404.5g
    Last edited by sissypants; 4 Days Ago at 07:45 AM.

  61. #261
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    calibrating spokes with a snark as I mentioned above ? yeah, with metal spokes...nope.

    wanted to say my idea of chromatic tuning with a Snark to check spoke tension is problematic in real use...and only good if you do not ride the wheel or actually use it.

    I tested three wheels last night. Two wheels were normal 3 cross spoke patterns, one was no overlapping spokes. In a bike stand, Snark tuner is very accurate and repeatable when a specific spoke was struck, but each spoke, even on a perfect wheel, will not 'tune' the same as the others next to it.

    so I rolled down the hallway and back... bodyweight only, and retested. All spokes were now different on the Snark from initial test.

    so, the chromatic scale and a Snark has too fine resolution to be practical....and just tiny deflection will change a spoke frequency, and that is at same temperature, and not even actual riding, just rolling with bodyweight.

    it might be practical if Snark showed on screen 1/2 octave range instead of one note range...but with it's small screen and small display range, problematic
    Last edited by 127.0.0.1; 4 Days Ago at 09:07 AM.
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  62. #262
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    Note of a 14/15 steel butted spoke on a 700c wheel with some reasonable assumptions:

    98 kgf: F# / Gb, 330 Hz
    109 kgf: G4
    123 kgf: G# / Ab
    138 kgf: A4, 440 Hz

    This roughly corresponds to the +-20% range and 130 kgf limit in the Park TM-1 instructions, for example. So yeah, there's not a lot of scale to work with.

    To do this calculation for the fiber spokes, need values for mass per length of the rope (linear density) and length of free section (wavelength). It's going to be an octave-ish higher.

    Wave speed in cm/sec = sqrt( (tension in dynes) / (linear density in g / cm) ), Tension force conversion is 9.88E5 dyne/kgf
    Frequency = 2 x wave speed / spoke length in cm

    Done in CGS and not MKS just because that's how I found the equations

  63. #263
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    In my opinion, due to the DIY nature of the spokes, I don't think that spoke frequency is be the best approach, as suggested before a +150Kg scale for calibration and the use of a Jobst Brandt design tensiometer should produce better results.

  64. #264
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    ^^^Agreed, I just enjoy this stuff

  65. #265
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    No need for Snark
    Just this app
    "Spectrum analyzer" on play store.
    It identifies the peak and labels it. Works great. Hold the microphone right near the spoke.

    The spokes are not constant mass per length due to the splice and the end, but they should be pretty consistent spoke to spoke. You will probably go for something around 650-700Hz. Higher pitch then steel spokes.

  66. #266
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    I figured since the rope-over-spoke section would be quite a lot heavier than a spoke alone much less the rope, it would be safe just to omit it from the wavelength. The whole length would have multiple modes and make a nasty chord but the highest note would still be from the unsupported length of the rope alone.

    The app I found a couple years ago was "ProTuner" and it did what I wanted although I hadn't launched it in a long time and it's acting broken now. Edit... yep it's a goner.

    I also have the Gates belt drive tensioner app but it just doesn't work that well.

  67. #267
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    I use this one:
    https://play.google.com/store/apps/d...com.vuche.asap

    When truing my wheels I just place the cell phone on the truing stand and pluck the spokes while running the app. I did change some options to help me discerning the peaks.

  68. #268
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    Finished!
    It came out surprisingly true. I will still take it to a shop to finish it.
    I've never built or even trued a wheel before.
    Make your own polymer (UHMWPE) spokes?-ijxih0t.jpg
    Make your own polymer (UHMWPE) spokes?-lnihwfa.jpg
    Only 3 left.
    Last x1700
    And two Carbonfan rims
    I have an DT swiss carbon 180 for the rear, looking for a good light front hub (centerlock)
    front will be 30mm ID, rear 27mm ID

    I had one pull out while tensioning. The threads were bad, so when I was grabbing the spoke end, it put a torque on the glued joint.

    Make your own polymer (UHMWPE) spokes?-zctjxs7.jpg

    https://youtu.be/FZV-rrk2jDc

  69. #269
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    I just tensioned again and targeted 500Hz.
    Btw removed spokes: 183.3g
    Replacement spokes: 55.16g

    Make your own polymer (UHMWPE) spokes?-ibsiw0f.jpg
    Make your own polymer (UHMWPE) spokes?-r3u15ok.jpg

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