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  1. #551
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    Quote Originally Posted by mces View Post
    Where are you getting this price?
    Website called Promotive. It's a site that offers discounts on many brands but you have to be a member of certain organizations such as a police officer, military, fire/ems. There's also a bunch of companies that qualify if you're an employee. I can get pretty good discounts on a bunch of stuff such as WTB, Kenda, Rudy Project, Crank Bros., Fox. Those are a few of the cycling brands but there's a lot more. Over 350. I've used them once and that was an order of Skratch Labs...I got 40% off that order.
    Cannondale F29 carbon
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  2. #552
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    Does someone received a recent i23 rim from CRC (especially 650b)?
    I want to know if their current stock is near manufacturer weight or is it like the i23 I get last year which where 30g more heavy (490g instead of 460g).

  3. #553
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    Mac_Aravan,

    are you sure it's an i23? See my post above, I had an i25 with i23 labels from CRC recently. Measure inner width to be sure.
    26" rigid SS 4130 BB7 nylon-flats ESI latex-tubes non-lubricated-8spd

  4. #554
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    Yes it was an i23, i25 were not even announced when I ordered them (Q1 2013).
    I think it was the first wt69 alloy batch, as I thought I will have 7000 alloy (and glad I had the new one).

    I ask that because KOM i23 are on sale right now, and I will switch to 650b in a few month.
    KOM are lighter but frequency are a solid performer for me, If there is still so much difference between quoted and real weight, I might be tempted by lighter KOM.

    Edit: I will check to be sure!

  5. #555
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    Quote Originally Posted by Mac_Aravan View Post

    I ask that because KOM i23 are on sale right now, and I will switch to 650b in a few month.

    Edit: I will check to be sure!
    Where are KOMs on sale?

  6. #556
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    At ChainReactionCycle, but only interesting for europeans.

  7. #557
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    Just got my KOM i23, really good finish (brushed) and subtle graphics.
    Weight is in line with specs (428g vs 425 claimed), that's a change from my freq i23.
    4D drilling is a little bit different from frequency i23 as bottom is not tapered, probably to give better strength.

  8. #558
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    Hi, I am in the process of buying the components for a set of Frequency i23 650b, with DTSwiss 350 hubs 6 bolt (12x142mm rear, 15x100mm front), and DT Swiss Competition spokes, and have the wheels build by a LBS. However I don't know the exact spoke length needed.

    From the spoke calculator at prowheelbuilder.com, the front spoke lengths are FRONT Left - 273.6mm, Right - 275.8mm, and REAR Left - 274.8mm, Right - 274.7mm

    Do I have to buy 272, 274 or 276mm spokes ? Thanks !

  9. #559
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    Go ahead and get all the correct lengths, rounding up. Going by your spoke calc, you'll need 274, 276, and 275. *You can probably "get away" with lacing all with 275, but I like to have the right amount of thread for my nipples.

  10. #560
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    Only 274mm and 276mm options for DT Swiss Competition.
    So basically the right choice would be to get 16 274mm spokes for the front, and 48 276mm spokes for the front and rear.

  11. #561
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    WTB Frequency i23 AM wheelset: alternative to Flow rims

    Quote Originally Posted by xs101 View Post
    Hi, I am in the process of buying the components for a set of Frequency i23 650b, with DTSwiss 350 hubs 6 bolt (12x142mm rear, 15x100mm front), and DT Swiss Competition spokes, and have the wheels build by a LBS. However I don't know the exact spoke length needed.

    From the spoke calculator at prowheelbuilder.com, the front spoke lengths are FRONT Left - 273.6mm, Right - 275.8mm, and REAR Left - 274.8mm, Right - 274.7mm

    Do I have to buy 272, 274 or 276mm spokes ? Thanks !
    Start over with a different calculator.
    The Prowheelbuilder calc is garbage.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  12. #562
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    I am no wheel pro, but I did build my own wheel set.

    I would be cautious about going "longer".
    The rear I would choose 274 both sides.
    The front 274 & 276 (check DISH early and watch it as you bring on the tension)

    I rounded UP on one of my numbers and I had BAD Dish from the very start.
    So I rounded down, bought new spokes and BAMM!! Dish almost perfect when nipps are at the bottom of the threads before tension begins.
    Just a rookies .02c
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  13. #563
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    All right tried the DT Swiss Calculator, FRONT Left - 270.4mm, Right - 272.6mm, and REAR Left - 271.5mm, Right - 271.1mm. So I guess 272 for all spokes then.

  14. #564
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    Ride MORE = Live Longer
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  15. #565
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    This calculator gives me : FRONT Left - 270.6mm Right - 270.7mm, and
    REAR Left - 271.9, Right - 274.9mm

    Quote Originally Posted by Burt4x4 View Post

  16. #566
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    When I was doing my first lace up I too was getting conflicting numbers from all the calculators out there.
    You have to go with one and forget the rest. I did the exact measurements that the UK site ^^^ says to measure (click on the tabs above to see measurements needed) and had good luck with the results.
    It felt like to me that the UK site had a great reputation and some of the Pro Wheel Builders here link to that calculator as a reference and or as being a "good" one to use..
    another .02c :-)
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  17. #567
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    Bumping a bit of an older thread here, but building up new wheels for my Bronson C. Focus is light(ish) weight, width, cost, and durability. (Thus AL)

    WTB KOM i25 front
    American Classic 15mm Thru Axle front hub
    WTB Frequency i25 rear
    Bike Hub Store MTB270 (Bitex MTR12) 12x142 rear hub
    Sapim Laser spokes
    32h, 3x pattern

    On paper, my wheelset should come in right around 1710 g and $430. Not bad for a 650b wheelset that I can ride and not worry about.

    Debated a KOM i25 rear, but I'm a rear rim basher.

    Also debated Flow's, but the Stan's 2nd Gen BST design is really tough to mount some TR/TLR tires.
    I like 'em low, long, slack and playful

  18. #568
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    Quote Originally Posted by Mac_Aravan View Post
    Does someone received a recent i23 rim from CRC (especially 650b)?
    I want to know if their current stock is near manufacturer weight or is it like the i23 I get last year which where 30g more heavy (490g instead of 460g).
    I have a650b i23 from crc pretty much bang on for weight.
    A great tubeless rim, love it
    " I don't ride park"

  19. #569
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    Why KOm's , there is such small difference in weight and the reg frequeency rims are so freaking tough..KOM's not so tough
    Quote Originally Posted by hokiebrett View Post
    Bumping a bit of an older thread here, but building up new wheels for my Bronson C. Focus is light(ish) weight, width, cost, and durability. (Thus AL)

    WTB KOM i25 front
    American Classic 15mm Thru Axle front hub
    WTB Frequency i25 rear
    Bike Hub Store MTB270 (Bitex MTR12) 12x142 rear hub
    Sapim Laser spokes
    32h, 3x pattern

    On paper, my wheelset should come in right around 1710 g and $430. Not bad for a 650b wheelset that I can ride and not worry about.

    Debated a KOM i25 rear, but I'm a rear rim basher.

    Also debated Flow's, but the Stan's 2nd Gen BST design is really tough to mount some TR/TLR tires.
    " I don't ride park"

  20. #570
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    Frequency i25 rear b/c I'm a rear wheel basher.

    KOM front b/c I'm not a front wheel basher. I debating going with a Nextie carbon rim for the front... But shipping from China for one rim is pretty spendy.

    Difference in weight is close to 100g. They both came in heavy, but the i25 came in heavier of the two.

    100g is close to 1/4 lb. Every gram/oz of rotating weight counts!
    I like 'em low, long, slack and playful

  21. #571
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    copy that , are you going tubeless? Im running i23's freq with gorilla tape and stans , was a very easy to setup. Mine held air with no sealent.impressive rim design
    " I don't ride park"

  22. #572
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    Yes. Will use my roll of blue generic Scotch strapping tape.

    Previously had i23's (about 2 years ago) and they set up great.
    I like 'em low, long, slack and playful

  23. #573
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    Wheels are laced. Will tension and true tomorrow night.

    KOM i25 27.5 front
    AM Classic 15mm thru axle front hub
    Frequency i25 27.5 rear
    BHS MTB270 rear hub w/ XD driver
    32h, silver Sapim Laser spokes & silver brass nipples

    745g front
    974g rear

    1719g for the wheelset, I can live with that.
    I like 'em low, long, slack and playful

  24. #574
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    Frequency rims are the best ones IME to go with aluminum nipples (if you trust those at all). No funny shaped steel eyelet to remove material from nipple head, and the directional drilling makes life so much easier for the nipple and the spoke's threaded part (so the rims are also great to go with 1.8 mm threaded spokes).
    26" rigid SS 4130 BB7 nylon-flats ESI latex-tubes non-lubricated-8spd

  25. #575
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    The directional holes look really interesting when you're used to seeing the regular style rims
    Last edited by 06HokieMTB; 11-11-2014 at 09:06 AM.
    I like 'em low, long, slack and playful

  26. #576
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    Remember those cracks around nipple holes on early i23s? These may have resulted from overtensioned spokes, which is very easy to do with directional drilling (and especially if brass nipples are used) if one is used to go by perceived torque on spoke wrench.
    26" rigid SS 4130 BB7 nylon-flats ESI latex-tubes non-lubricated-8spd

  27. #577
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    Quote Originally Posted by J. Random Psycho View Post
    Remember those cracks around nipple holes on early i23s? These may have resulted from overtensioned spokes, which is very easy to do with directional drilling (and especially if brass nipples are used) if one is used to go by perceived torque on spoke wrench.
    Also the early i23's were 7000 series aluminum,(lots of problems) they quickly switched to Wt69 Aluminum
    " I don't ride park"

  28. #578
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    I'm looking forward to build a wheelset for my hardtail 29er, which is used for mild touring, no drops, jumps etc., on top of that I'm a clyde at 240 geared.

    Is the i23 KOM for me? Any clydes with similiar experience around here?

  29. #579
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    I've just had a pair of 650b KOM i23s turn up to build for the girlfriend's Mondraker Foxy Carbon (eBay bargain frame)... because the graphics will match. I ask you.

    First job... weigh in:

    Name:  Screen Shot 2015-01-20 at 00.04.41.png
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    Second job... clean up all the spoke holes and get the burrs and swarf out of the rim cavity:

    Name:  Screen Shot 2015-01-19 at 23.56.21.png
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    Third job... weigh the swarf.... nah. It didn't hit a gram.

    Fourth job... clean up everything so she doesn't know I've been deburring rims on the rather lovely floral kitchen tablecloth.

    Spec is going to be:

    KOM i23 650b 32h
    Shimano XTR M9010 hubs F:15/100 R:12/142
    Sapim Cx-ray F:274/276 R:276/274
    Sapim hex aluminium nipples gold

    Price on the rims was exceptional from CRC so I had some budget left that went to the spokes. I've been running my Devinci Spartan on a set of Syntace MX W30 650b wheels that come in at 1580g built with Cx-rays so I figured for the girl's build for her less burly bike Cx-rays would fit the bill. The hub choice should give a quiet freewheel, unlike the Syntace.

    ~1480g expected.

    I'm going to have a bit of an engineering play during the build by cross-referencing the spoke tensions to the plucked pitch using a freebie Android guitar tuner app: PitchLab.

    WTB Frequency i23 AM wheelset: alternative to Flow rims-screen-shot-2015-01-20-00.28.25.png

    I've already done the preliminary calculation for the spokes and set up a custom two string guitar for the front wheel:

    Name:  Screen Shot 2015-01-20 at 00.33.13.png
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    For those that are interested, the B4 and C5# musical notes relate to ~490hz and ~550hz respectively which calculations suggest should be about right; maybe a bit high. I normally tune relative tensions by ear anyway so it fits my methodology. This will be backed up with tension meter measurement.

  30. #580
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    petercarm,

    With CX-Rays you may find that most spoke tensiometers press on the spoke too strong to get precise readings for lower tensioned side of an asymmetrically dished wheel. Readings end up too close to zero so it's hard to tell differences between them. What I do with CX-Rays is trust a tensiometer more on the "high" side, and trust ears more on the "low" side.

    How do you arrive at those frequencies? Maybe I've just been up for too long but I get (clearly wrong) results 2 orders of magnitude below yours when I try to use Mersenne's equation ( f = sqrt(tension / linear_density) / (2 * spoke_length) ) for fundamental frequency for stainless steel, 1.5 mm diameter, round spoke tensioned to 120-125 kgf.
    26" rigid SS 4130 BB7 nylon-flats ESI latex-tubes non-lubricated-8spd

  31. #581
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    WTB Frequency i23 AM wheelset: alternative to Flow rims

    Quote Originally Posted by J. Random Psycho View Post
    Readings end up too close to zero
    This sounds and looks (based on TM-1 conversion chart) pretty odd. What hubs are you using?
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  32. #582
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    WTB Frequency i23 AM wheelset: alternative to Flow rims

    Quote Originally Posted by J. Random Psycho View Post

    With CX-Rays you may find that most spoke tensiometers press on the spoke too strong to get precise readings for lower tensioned side of an asymmetrically dished wheel. Readings end up too close to zero so it's hard to tell differences between them. What I do with CX-Rays is trust a tensiometer more on the "high" side, and trust ears more on the "low" side.
    That's pretty much my plan. Or even simpler, spot check one tension vs. tone on the high side and tune by tone for all the high side, with dish and even tone taking care of the low side.

    Quote Originally Posted by J. Random Psycho View Post
    How do you arrive at those frequencies? Maybe I've just been up for too long but I get (clearly wrong) results 2 orders of magnitude below yours when I try to use Mersenne's equation ( f = sqrt(tension / linear_density) / (2 * spoke_length) ) for fundamental frequency for stainless steel, 1.5 mm diameter, round spoke tensioned to 120-125 kgf.
    m/l=0.01635 kg/m ( 64x 260mm CX-ray= 272g)
    T=1275 N (130kg f)
    L= 0.274m (with some bracketing for shortening at the spoke nipple)

    √(1,275÷0.01635)÷2÷0.274=509.58hz

    Bracketed:
    √(1,275÷0.01635)÷2÷0.262=532.92hz

  33. #583
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    Quote Originally Posted by meltingfeather View Post
    This sounds and looks (based on TM-1 conversion chart) pretty odd. What hubs are you using?
    The usual suspects mostly, such as DT 240s 6-bolt 135 mm rear, with rim centered over hub. No exotic dishing.

    Readings for low side are below 10 on TM-1, and there are big tension differences between neighbouring points on the dial. But I use DT Tensio Analog 2 currently, and while its dial is more precise, it bends a spoke even more than TM-1. I guess the low side of thin steel blade spoked wheel is where Jobst Brandt/Wheel Fanatyk tensiometer would shine, but can't see myself getting hold of one anytime soon, because it wouldn't be practical expense.


    petercarm,
    I was using kg/mm for linear density (same digits but the number is 1000 times less), kgf for tension and mm for spoke length. Guess I need more sleep..
    26" rigid SS 4130 BB7 nylon-flats ESI latex-tubes non-lubricated-8spd

  34. #584
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    Quote Originally Posted by J. Random Psycho View Post
    I was using kg/mm for linear density (same digits but the number is 1000 times less), kgf for tension and mm for spoke length. Guess I need more sleep..
    Newton conversions are always lying around to trip you up.

    Once I get my 274/276 spokes near some accurate scales, I'm thinking I'll be able to get a linear density validated for the butted ends vs the flat/drawn middle and modify the Mersenne's equation to account for that.

    frequency=sqrt(tension) /
    (
    sqrt(linear_density(butted section)*2*length(butted section)
    +sqrt(linear_density(centre section)*2*length(centre section)
    )

    This would drop my previous result of 509hz down to 500hz for a 12mm butted length.

  35. #585
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    Quote Originally Posted by petercarm View Post

    I'm going to have a bit of an engineering play during the build by cross-referencing the spoke tensions to the plucked pitch using a freebie Android guitar tuner app: PitchLab.

    I've already done the preliminary calculation for the spokes and set up a custom two string guitar for the front wheel:
    You have just moved way up on my list of favorite science dorks on this forum!
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  36. #586
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    Quote Originally Posted by petercarm View Post
    Newton conversions are always lying around to trip you up.

    Once I get my 274/276 spokes near some accurate scales, I'm thinking I'll be able to get a linear density validated for the butted ends vs the flat/drawn middle and modify the Mersenne's equation to account for that.

    frequency=sqrt(tension) /
    (
    sqrt(linear_density(butted section)*2*length(butted section)
    +sqrt(linear_density(centre section)*2*length(centre section)
    )

    This would drop my previous result of 509hz down to 500hz for a 12mm butted length.
    I think you need to go ride your bike more....
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  37. #587
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    WTB Frequency i23 AM wheelset: alternative to Flow rims

    Quote Originally Posted by dustyduke22 View Post
    I think you need to go ride your bike more....
    I think you're right.

    I've refined the model a bit and it now takes into account 4 and a bit segments of the spoke:
    1.butted section leaving hub flange
    2.centre section
    3.butted section before nipple
    3.5 section sleeved by nipple but not engaged
    4.threaded section engaged by nipple

    The segments are used for both elongation and resonance calculations as appropriate. It also now does a lookup to spit out the nearest musical notes, with colour coding to indicate accuracy.

    I'm looking forward to seeing how this works out. Tests on existing wheels show that there is a knack for getting the spoke fundamental resonance to ring and get picked up by the microphone. It does work but it is a bit fiddly. Hubs have arrived and measurements verified. Spokes are on order.

  38. #588
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    Quote Originally Posted by petercarm View Post
    4.threaded section engaged by nipple
    I think this part shouldn't be oscillating at spoke frequency, it's effectively one with nipple and rim under that compressive force.
    26" rigid SS 4130 BB7 nylon-flats ESI latex-tubes non-lubricated-8spd

  39. #589
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    WTB Frequency i23 AM wheelset: alternative to Flow rims

    Quote Originally Posted by J. Random Psycho View Post
    I think this part shouldn't be oscillating at spoke frequency, it's effectively one with nipple and rim under that compressive force.
    One end of it is attached to the next bit that is vibrating and we're modelling a standing wave...

    I could stress out more about what resonances are present in the rim but experience is that tuning by ear is very straightforward for relative tension. If I can hear the resonance of the spoke (not the rim), it appears valid to model the spoke resonance (and assume a rigid rim). I need to make some sort of determination as to where the spoke ends and the rigid rim begins.

    If I had to hazard a guess it would be that each change in profile produces a reflection and resonance of its own, so I do not expect a bell-like clarity or a clean sinusoid.

    Whichever way I swing the model I still get somewhere between 500hz and 540hz matching 130kgf. From a bracketing point of view that is probably all I need.

    In practice it may be easier to have a tone generator give me my pitch and then just use my ears... but now I've invented the game of using the guitar tuner App, I've got to see it through.

  40. #590
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    Quote Originally Posted by petercarm View Post
    I think you're right.

    I've refined the model a bit and it now takes into account 4 and a bit segments of the spoke:
    [...]
    4.threaded section engaged by nipple

    The segments are used for both elongation and resonance calculations as appropriate.
    This is a very complicated problem... would love to see your work on it and whether it has any material affect whatsoever. I have my suspicions.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  41. #591
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    WTB Frequency i23 AM wheelset: alternative to Flow rims

    Quote Originally Posted by meltingfeather View Post
    This is a very complicated problem... would love to see your work on it and whether it has any material affect whatsoever. I have my suspicions.
    Agreed.

    There are all sorts of possibilities in the theoretical models. Vibration of a tensioned string is one model. With appreciable cross-section this model becomes less valid as you have to take account of the shear/bending deformation of the element providing some of the energy storage.

    I have modeled simple refraction at the transition from spoke to nipple, using the tensioned string model (Mersenne's equation), which will give a lower bracketing result for the frequency. I have also modeled the nipple as a rigid structure, determining reflection and shortening of the vibrating element. This gives an upper bracket value for frequency. In reality there will be a mix of the two (and other modes) with different decays. At these numbers (130kgf) the difference appears to be ~30hz which is ~one musical tone (12TET) at the frequencies I'm expecting which would otherwise account for a ~15kgf discrepancy.

    Experimentally I should be able to determine if I'm within that 15kgf target bracket and I'd hope to make an empirical judgement that could give me maybe an accuracy to half that interval.

    The method is more accurate at lower tensions so it could be valid to tune the NDS to an appropriate value and rely on the dishing and spoke angle to determine the DS.

  42. #592
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    This is becoming the most serious research on using sound for measuring spoke tension that I have ever seen. I'm staying tuned (no pun intended).
    26" rigid SS 4130 BB7 nylon-flats ESI latex-tubes non-lubricated-8spd

  43. #593
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    [Minor edit of the end of the prior post.]

  44. #594
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    WTB Frequency i23 AM wheelset: alternative to Flow rims

    Oh and it's not "serious".

    The spokes arrived in the post this morning so I'll be shelving theory and getting on with lacing up these bad boys.

  45. #595
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    I've been working on the front wheel tonight, cross checking tensions and pinging spokes.

    The guitar tuner approach didn't work reliably. The number of harmonics and reflections meant that the predominant pitch was considerably higher than the model predicted. I suspect the lacing of the spokes at the third cross is probably mostly responsible as I was getting 700hz and greater while the calibrated Sapim tension meter was still giving numbers in the 110kgf range.

    I have a Syntace wheelset that uses CX-Rays that aren't laced at the third cross. I'll try to get some reference tension and pitch readings from those wheels and see if the pitch drops back where I was expecting it.

  46. #596
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    Quote Originally Posted by petercarm View Post
    I have a Syntace wheelset that uses CX-Rays that aren't laced at the third cross.
    Are the spokes in it straight pull or j-bend?
    26" rigid SS 4130 BB7 nylon-flats ESI latex-tubes non-lubricated-8spd

  47. #597
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    J bend.

  48. #598
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    Weird! Here's a close up of Syntace W30 MX rear, and I see interlacing there: WTB Frequency i23 AM wheelset: alternative to Flow rims-5-syntace.jpg
    26" rigid SS 4130 BB7 nylon-flats ESI latex-tubes non-lubricated-8spd

  49. #599
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    I'd seen this referenced in this review of the Syntace W35s. My W30s are like this.

    One little quirk is that the spokes aren’t actually interlaced like on most wheels; apparently the über-demanding Syntace customer wants quiet wheels, and eliminating the interlacing prevents the spokes ‘plinking’ under heavy side loads.
    See more at: Syntace W35 MX Wheels | Bicycling Australia

  50. #600
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    Wow. Perhaps their hubs have very small spoke holes so spoke ends sit there tightly enough and the wheels can get away without spokes being interlaced. Looking at how far spoke heads protrude on the inner, non beveled side of holes (think Tune hubs), this may be the case indeed.
    26" rigid SS 4130 BB7 nylon-flats ESI latex-tubes non-lubricated-8spd

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