The wheelbuilding thread

Everything about building wheels, glueing tubs, etc.
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Calnago
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by Calnago

WinterRider wrote:
bm0p700f wrote: However what I do not know for certain is if there drop is radial stiffness with using Laser spokes NDS is big enough to remove the benefit of using them.


I ran some numbers thru the Machine Head software. 50% NDS tensions listed for each effective spoke diameter.. figures for elongation of that spoke with 120 kgf DS tension.

1.5 = .4742mm = .0186"

1.8 = .3304mm = .1301"

2.0 = .2673mm = .0105"

So.. the actual difference in elongation between 1.5's and 2.0's on the NDS is .008" Hence to date I have not bothered using lighter spokes on the NDS.. as IMO the added elongation is not worth the bother.

Butted spokes of course.. absorb more of the shock of re-tensioning of the spoke.. saving the elbow material that strain alone.


@WinterRider, thanks for that info. I was wondering that exact thing, how much more would a DT Revolution spoke stretch versus a DT Competition. I've been building up several sets of Nemesis/Record wheels over the last several days and decided I'd like to try the Revolutions on the NDS of one set. I could only get 300mm length spokes where 301-302 would have been better but thought the greater elongation might compensate. Bottom line is, as your data points out, the difference is fairly negligible. The spokes are just long enough that I don't think there will be a problem, especially with the lower tension of the NDS. Please correct me if you've worked with this combination and think I'm wrong about that. I am anxious to try them out in a comparison with the same wheel built with comps on both sides. I only ever build these "Classics" wheels with 3x both sides and I always seem to end up with a NDS/DS tension ratio of about 43% or so, with a drive side tension in the 120kgf range. The Revolutions on the NDS are more of an experiment for myself but will likely just continue using DT Comps on both sides in the future. After all, apart from the ride, it's the robustness of a wheelset like this that is its appeal, and so I figure if there hasn't been a problem with spokes before (and there hasn't) then why change. And I just like the symmetry of a 3x pattern on both sides of a wheelset like this.
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by Weenie


eric
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by eric


So.. the actual difference in elongation between 1.5's and 2.0's on the NDS is .008" Hence to date I have not bothered using lighter spokes on the NDS.. as IMO the added elongation is not worth the bother.



How did you come to that conclusion? I'm not arguing either way, just curious as I don't know if 8 thou is a little or a lot in this case.

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WinterRider
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by WinterRider

eric wrote:

So.. the actual difference in elongation between 1.5's and 2.0's on the NDS is .008" Hence to date I have not bothered using lighter spokes on the NDS.. as IMO the added elongation is not worth the bother.



How did you come to that conclusion? I'm not arguing either way, just curious as I don't know if 8 thou is a little or a lot in this case.


The data comes via MachineHead software.. the figures stated for elongation of the spoke at said tension. His data in mm's.. then converted to inches.

IMO .008 isn't significant to warrant the use of light butted on the NDS... unless.. those few grams are important to the user.

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WinterRider
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by WinterRider

bm0p700f wrote: The Revolutions on the NDS are more of an experiment for myself but will likely just continue using DT Comps on both sides in the future. After all, apart from the ride, it's the robustness of a wheelset like this that is its appeal, and so I figure if there hasn't been a problem with spokes before (and there hasn't) then why change. And I just like the symmetry of a 3x pattern on both sides of a wheelset like this.


The Rev's being 1.5 vs the 1.8 mid section of the Comp's would give around .004-5 thousandths difference in elongation under tension... more of less. IMO the weight savings would be the only reason for the chg.

I've used no DT Swiss spokes to date... Sapim's here so far. As I believe I noted earlier... my building is for personal use to date only... some of those wheels go out on bikes I've moved. My goal is learning all I can per practical knowledge of wheel building... then refining the wheels I build.. less weight per given strength/durability.

The theory behind wheel building is interesting.. but as I've read more than once online... theory and the reality of that outcome can/does vary. Rider weight... riding style.. the roads.. means a wide range of conditions to challenge one's "wheels".

eric
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by eric

WinterRider wrote:
IMO .008 isn't significant to warrant the use of light butted on the NDS..


That's the part I am asking about. Why do you say .008" not significant? Your numbers show the 1.5mm spoke has a bit less than twice the longation of the 2.0mm spoke, about 1/2 a mm vs about 1/4.

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WinterRider
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by WinterRider

eric wrote:
WinterRider wrote:
IMO .008 isn't significant to warrant the use of light butted on the NDS..


That's the part I am asking about. Why do you say .008" not significant? Your numbers show the 1.5mm spoke has a bit less than twice the longation of the 2.0mm spoke, about 1/2 a mm vs about 1/4.


Elongation... prevents the spoke going slack under hard impacts. .008 isn't enough to prevent this under the worst circumstances.. from what I can determine. Does your experience or references show otherwise?

'worst circumstances' >> descending a hill and being forced to take a pothole at over 20 mph. That is my scenario experienced here.. I'm sure others could site much more severe instances. With some harder tires I suspect any wheel arrangement would allow some of the spoke/s to de-tension.

eric
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by eric

How do you know spokes didn't detension when you hit the hole? Did you measure it in some way?

But I think the point is to keep the NDS spokes from detensioning during regular riding, not just on big impacts.

That's what Jobst says anyhow, and it seems to work for me. I break fewer NDS spokes when I use lighter spokes on the NDS. But that's just my experience.

bm0p700f
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by bm0p700f

One of the quote above from me is actually written by Calngo! When quoting get the original author right!

I have checked the elongation numbers. I work in mm I do not understand inches.

change in length = original length*(stress/young moduls).

For Sapim spokes young mod = 193 GPa approx
For NDs spokes at 500N stress for 1.5mm Laser spokes is 2.83x10^8 Pa
For NDS spokes at 500N stress for 1.8mm Race spokes is 1.97x10^8 Pa

I will take original length to be 290mm or 0.29m

So change in length will be for 1.5mm spokes 0.425mm That is quite alot of extension.
For 1.8mm spokes the change in length will be 0.296mm. that is a fair bit less. So I agree with winter rider calculations. I have just noticed after writing all this he had quoted mm.

In any case that extra extension of 0.1mm is quite useful as 80kg rider on a 4000 n/mm radial stiffness wheel will cause 0.1mm of radial deflection. This is the reason why I use them. As Eric says it possibly helps stop the spokes going slack in day to day riding. Also it is more useful I think when building a rear wheel like the one I am about to ride, a low max tension (1100N) rim with hub that give a 44% tension balance.

However as I pointed out the radial stiffness of a wheel built with thin NDS spokes is likely to be lower but I do not know if the difference negates the benefits of thin NDS spokes. If anyone can work that out I would be grateful, other I will have to have a go one day when I have worked how.

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WinterRider
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by WinterRider

eric wrote: I break fewer NDS spokes when I use lighter spokes on the NDS. But that's just my experience.


What I think of.. is what I term 'head slap' ...when the spoke head de-tensions and then assumes full tension. The butted spoke softens that head impact and strain on the elbow bend. The metal formula is of better quality if some of the butted spokes too.. from what I have read.

Rim shrinkage.. per MachineHead software.. is .905mm at 120 kgf DS.. or .0356" One mm = .03937"

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WinterRider
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by WinterRider

bm0p700f wrote: However as I pointed out the radial stiffness of a wheel built with thin NDS spokes is likely to be lower but I do not know if the difference negates the benefits of thin NDS spokes. If anyone can work that out I would be grateful, other I will have to have a go one day when I have worked how.


THAT.. is why I got interested in the triplet concept. For now.. I think of for instance a 16 spoke DS triplet as being as strong as a 32H wheel. The NDS 8 spokes are very near or equal to DS tensions.. meaning a very strong wheel both ways. And while the trial 18-10 I built is not a true triplet.. the concept is of course same. That wheel feels very strong.. but riding it will tell the actual story.

As noted previously.. I've used Sapim Strong on these triplets. Definitely not WW.. yet saving the 8 spokes on the traditional 24H triplet means a very well balanced wheel for strength. IN essence.. a trade off for 8 less spokes and a much stronger overall wheel.. for just slightly less weight.

Caveats for the triplets of course... center drilled rims are needed. And the next one I'll lace NDS all heads in 1x... aiming to minimize the NDS flange strain.

bm0p700f
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by bm0p700f

Spoke tension (so long as the spokes are tensioned will not affect radial stiffness. So a triplet wheel will have lower radial stiffness than a 32 3x spoke wheel with the same gauge spokes used in both wheel. Whether the drop in radial stifness is significant I do not know.

What I do know is the difference in radial stiffness for 0x, 1x, 2x, 3x, and 4x wheels is very small (in the order of 3% on a 36 spoke wheel) so it is very possible that the thin gauge spokes NDS does not make a significant difference to radial stiffness. I think this is likely but I cannot be certain. The same therefore would also be true for a triplet wheel. Of course this does not change the fact that spoke tension does not affect wheel stiffness.

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WinterRider
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by WinterRider

bm0p700f wrote:Spoke tension (so long as the spokes are tensioned will not affect radial stiffness. So a triplet wheel will have lower radial stiffness than a 32 3x spoke wheel with the same gauge spokes used in both wheel. Whether the drop in radial stiffness is significant I do not know.

Of course this does not change the fact that spoke tension does not affect (radial) wheel stiffness.


Bold & underlining mine... assuming your referencing radial stiffness.

I just do not understand that concept.

Is not.. radial stiffness a function of rim compression.. to some extent? That accomplished by spoke tension.... ?

Understand.. I'm just trying to learn something. :beerchug:

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WinterRider
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by WinterRider

WinterRider wrote:
KLabs wrote:

I've been looking online for a list/summary of rear hubs that allow radial lacing.. w/o any luck.
Anyone have a link or can other experiences with radial lacing NDS rear FH's?
.




From the Chris King website:
Does the hub warranty cover radial lacing?
Answer: The only Chris King hub to allow radial lacing is the R45 product line. The driveside of the rear hub should always have at least one cross.

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Calnago
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by Calnago

@WinterRider, @bm0p700f... although very theoretical, I am finding this disucussion fascinating as well. For me, who started using factory built wheels around 2000 with the first generation of Campy Nucleons, I have just in the last 2-3 years staretd revisiting the whole handbuilt tubular thing. Prior to that I had always ridden on clinchers. Anyway, while I have worked on numerous high end "superwheels" the only wheels I ever actually build from scratch are the classic low profile 32 spoke 3 cross wheels I grew up with (I know, boring). But they work, and I have to admit that I am really hooked on the ride quality (and looks) of my Nemesis/Record wheelsets. Like I mentioned, I've been building several sets of these recently and am actually experimenting with the DT Revolutions on the NDS on one of the sets but I haven't ridden them yet to see if I can actaully feel any difference on the road. Can you? I know the "theory" behind them, but they just seem so thin, and I'm a bigger guy at 195-200lbs, that I've felt more confident using the DT Comps both sides. I've never had a problem with spoke breakage in the past either, so using the Revolutions is more of a theoretical advantage for me I suppose.
Thanks.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

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WinterRider
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by WinterRider

Calnago wrote:@WinterRider, @bm0p700f... Like I mentioned, I've been building several sets of these recently and am actually experimenting with the DT Revolutions on the NDS on one of the set
Thanks.


My latest... flash I guess one could call it.. is trying some of those Sapim Super spokes on a rear. Half the weight of Sapim Strong... supposedly stronger overall per breakage. To date.. mostly I have avoided spokes that wind up when assembling. Those are 1.8 - 1.4 - 1.8's.. I suspect not laterally stiff enough for my weight. [?].

by Weenie


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