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PostPosted: Wed Mar 06, 2013 9:59 pm 
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Location: Santa Cruz, California, USA
Danny, when I tensioned my FarSports 24m tubulars I took the DS to 110kgf. I think if the rim can't handle that then its questionable if it's strong enough to ride on.


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PostPosted: Fri Mar 08, 2013 12:36 pm 
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I'm building up some new wheels and just after some advice.

Stans Alpha 28h rear 3cross DS and radial NDS (does this work?) with CX-ray's

*OR*

Stans Alpha 24h rear 16:8 lacing pattern — understanding this provides a more equally spoke tension but which would build a better wheel? I assume through greater spoke count it'll be the 28h option?

Also, would a 20h front radially laced be strong enough for a rider ~78kg? Currently thinking of pairing a 24h to the 28 rear but also have the option to go 20h and save a few precious grams, although strength really is my obvious first concern hence thinking 24h.

And I know they increased the strength of the 340 last year but will it still stand up to the job for me or shall I opt for the 400 on the rear? I think the set up should still yield a sub 1500g wheelset which would be ace but I'd love something closer to 1300g so would rather the 340.

So in short — 20/24h or 20h-24h/28h for a ~78kg rider?

Any help/advice much appreciated.


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Posted: Fri Mar 08, 2013 12:36 pm 


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PostPosted: Fri Mar 08, 2013 3:21 pm 
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How durable do you want these wheels to be? How hard are you on wheels- do you break spokes often? Rider weight is not the only factor.


A while back someone asked about soldering and tying improving wheel stiffness. I was re-reading Jobst's book last night and found that he did a test to determine that and found no improvement in either static lateral stiffness or tortional stiffness under load. Go read it for the details.


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PostPosted: Fri Mar 08, 2013 5:41 pm 
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@leejdavies-I wouldn't recommend the radial lacing on the NDS of that build. I've done that before with a 340/T11 combo, and I had problems with the non drive side going slack. I think that a 2x NDS would be far more practical. For the front wheel, a radial build would be just fine. Keep in mind that front wheels are usually much stiffer than rears because they have even relative tensions, where as rear wheels have a significant tension offset. For the hole count, you won't notice any difference between 20h and 24h. On the rear though I think you should overbuild a tad and go with a 28 hole, at least.

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PostPosted: Fri Mar 08, 2013 6:02 pm 
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A customer has asked me to build him a wheel using his parts O.K I said. I recieved the 20H Alpha 240 rim and 20H hub. What he did not tell me the hub is a brontrager affair drilled for paired spokes.

So I have a 20H rim with equidistant drilling and a paired spoke hub. Radial lacing heads out i what has been done before with this hub so that what I will again. How do I calculate the lengths for this one. It must be different to a normal radial wheel.

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PostPosted: Fri Mar 08, 2013 6:40 pm 
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@bm0p700f- Hmmm. Sounds like a can of worms to me. Contact Jeremy at Alchemy though. He's the guy I'd call on this one.

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PostPosted: Fri Mar 08, 2013 9:30 pm 
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I have already suggested a convential hubs. All the customer did was e-mail me a picture of the original wheel. I might have to break the bad news.

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PostPosted: Sat Mar 09, 2013 2:23 am 
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Hi all, more maths to explain effective Lateral Stiffness, which combines Bracing Angle and effective NDS Ratio. I believe that the following formula should be do that ...

((DS BA * DS spoke number) + (NDS BA * NDS spoke number)) * Effective NDS ratio = Effective Lateral stiffness (index) = ELS ... where Effective NDS ratio = Traditional NDS ratio * DS spokes / NDS spokes

Some examples ... DS BA = 3.7', NDS BA = 7.4', Traditional NDS ratio = 46%

20-8 ... Effective Lateral stiffness = ELS = ((3.7 * 20) + (7.4 * 8 )) * (0.46 * 20/8) = (74.0 + 59.2 ) * 1.15 = 153.18 ... where to get a decent 40H hub with decent FTF spacing (55 to 57mm) - 28H rim, only 4 more spokes :)

18-9 ... ELS = ((3.7 * 18) + (7.4 * 9 )) * (0.46 * 18/9) = (66.6 + 66.6 ) * 0.92 = 122.54

18-10 ... ELS = ((3.7 * 18) + (7.4 * 10 )) * (0.46 * 18/10) = (66.6 + 74 ) * 0.828 = 116.417

16-8 ... ELS = ((3.7 * 16) + (7.4 * 8 )) * (0.46 * 16/8) = (59.2 + 59.2 ) * 0.92 = 108.928

18-12 ... ELS = ((3.7 * 18) + (7.4 * 12 )) * (0.46 * 18/12) = (66.6 + 88.8 ) * 0.69 = 107.226

18-18 ... ELS = ((3.7 * 18) + (7.4 * 18 )) * 0.46 = (66.6 + 133.2 ) * 0.46 = 91.908

16-12 ... ELS = ((3.7 * 16) + (7.4 * 12 )) * (0.46 * 16/12) = (59.2 + 88.8 ) * 0.613 = 90.724

16-16 ... ELS = ((3.7 * 16) + (7.4 * 16 )) * 0.46 = (59.2 + 118.4 ) * 0.46 = 81.696

14-14 ... ELS = ((3.7 * 14) + (7.4 * 14 )) * 0.46 = (51.8 + 103.6 ) * 0.46 = 71.484

12-12 ... ELS = ((3.7 * 12) + (7.4 * 12 )) * 0.46 = (44.4 + 88.8 ) * 0.613 = 61.272 ... there are a lot of 24H 12-12 wheels in circulation - for light to medium weight, not powerful, riders? :)

When I look at these figures it suggests that the 20:8, 18-9, and 18-10 are excellent for lateral stiffness, as is the 16-8 :)
Significantly these results show that the traditional arrangements/builds, 12-12, 14-14, and 16-16, are at the bottom of the list for effective Lateral Stiffness ...
The 16-12 arrangement is well down the list, although it is equal to a 36H 18-18 arrangement (less 8 spokes) …

I will have a look at a formula for effective Torsional stiffness … Effective Torque Control :)

Please check and let me know what you think ... thanks KL :)


PS: 20-4 ... ELS = ((3.7 * 20) + (7.4 * 4 )) * (0.46 * 20/4) = (74.0 + 29.6 ) * 2.30 = 238.28 ... DS spoke tension is an issue and not enough NDS spokes, but if you are game to try it (I wouldn't, this is just an example) ... 24H rim and 24 spokes ... :)

Campagnolo do the 14-7 Triplet (21H rim), and I must say that I have not heard of any real issues with these wheels … very clever of them :)

Does DS/NDS spoke tensions have an effect on Lateral Stiffness? Well, they answer is most definitely (most definitely) ... yes, otherwise Campagnolo's 14-7 Triplet (21H rim) would not work :)


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PostPosted: Sat Mar 09, 2013 4:38 am 
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Damon Rinard's tests found that spoke tension did not effect wheel stiffness until the spokes went slack. (http://www.sheldonbrown.com/rinard/wheel/index.htm).


> 18-12 ... ELS = ((3.7 * 18) + (7.4 * 12 )) * (0.46 * 18/12) = (66.6 + 88.8 ) * 0.69 = 107.226

> 18-18 ... ELS = ((3.7 * 18) + (7.4 * 18 )) * 0.46 = (66.6 + 133.2 ) * 0.46 = 91.908

It doesn't make sense to me that removing six spokes would make a wheel stiffer. Perhaps I misunderstood the formula expressing your theory.


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PostPosted: Sat Mar 09, 2013 5:38 am 
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Hi eric, the NDS ratio is 46% for the 18-18, whereas the 18-12 is 69% ... that's a 23% improvement. Absolutely, if spoke tension plays no part at all, then you are absolutely correct, but maybe the testing method used was not completely correct ... maybe ... :)

A thing to remember though is that an assembled spoked wheels rim has been tensioned like a leaf spring, or torsion bar, on a car, but in a circular manner ... which is even stronger.
The rim has been pre-tensioned and pre-stressed, and with more pre-tensioning and pre-stressing (ie more spoke tension) it will become more resistant to the same lateral/radial forces that will act on it (and even torque effects) ... sound reasonable :)


Isn't it interesting that we do not hear of many (or any) issues with Campagolo's 14:7 triplet, 21H rim?
With 21 spokes it appears to be stronger than the current 16:8 24H rim arrangement ... 3 spokes less :)
It appears to be the relationship between the pre-tensioned rim, spoke placement, and even DS/NDS spoke tensions :) ... do you have any ideas re 14:7 triplet, 21H rim :)


Last edited by KLabs on Sat Mar 09, 2013 5:49 am, edited 1 time in total.

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PostPosted: Sat Mar 09, 2013 5:49 am 
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Location: Adelaide, Australia
KLabs wrote:
Isn't it interesting that we do not hear of many issues with Campagolo's 14:7 triplet, 21H rim?
With 21 spokes it appears to be stronger than the current 16:8 24H rim arrangement ... 3 spokes less :)
It appears to be the relationship between the pre-tensioned rim, spoke placement, and even DS/NDS spoke tensions :) ... do you have any ideas re 14:7 triplet, 21H rim :)


I'm gonna say they have optimized the hub geometries for 14:7 triplet, Some triplet hubs that I see are just "regular" hubs with a 16:8 drilling

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PostPosted: Sat Mar 09, 2013 6:03 am 
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verycreativeusername wrote:
I'm gonna say they have optimized the hub geometries for 14:7 triplet, Some triplet hubs that I see are just "regular" hubs with a 16:8 drilling


Hi verycreativeusername, absolutely, especially as only 21 spokes are used, and would most likely mean that the DS bracing angle has been increased, ie. better than 3.7' or the FTF spacing has been optimized (about 57mm).

... but I don't think that's the case. Have a look at these 11spd hub upgrades ... http://fairwheelbikes.com/cycling-blog/updates-and-news/hub-conversions-for-shimano-11-speed.html ... and you will see that the best NDS ratio was 51%, based on an ERD of 587, 24 spoke 12-12 2x/2x arrangement. Only 2 hubs in that group achieved a DS bracing angle of 3.7' ... the others were all less than 3.7' :)


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PostPosted: Sat Mar 09, 2013 6:32 am 
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It would appear that with 11spd we are entering an era of deep rims ( >=30mm), which are needed to improve the DS brazing angle.

If my maths is reasonably correct then my observations are that 20-8, 20-10, 18-9, 18-10, 16-8, 18-12, 18-18, and 16-12 spoke arrangements will again make non asymmetric and non OC shallow rims viable with 11spd hubs ... food for thought ... thanks KL :)


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PostPosted: Sat Mar 09, 2013 7:28 am 
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Hi all, I was thinking about the Lew Pro VT1 hub and I find it nice in the following ways :)

- the centre flange can be laced 2x or 3x or even 4x, and because it is in the same plane as the rim, can control all torque effects.

- because the centre flange is controlling all torque effects the DS/NDS flanges only need to control lateral effects (lateral stiffness) and as such can be laced 0x heads in.

- also, fewer DS/NDS spokes are required because they only need to control lateral stiffness (not torque effects)

- DS/NDS spoke tension issues are more easily controlled (although Lew has made spoke/wheel repair to proprietary and difficult)

- this design can nearly be tested statically

- very clever design

What are your thoughts on this hub design ... thanks KL :)


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Posted: Sat Mar 09, 2013 7:28 am 


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PostPosted: Sat Mar 09, 2013 9:12 am 
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Location: Glermsford, Suffolk U.K
Klabs that maths makes no sense to me, the way you have worked it out is nonsense. I am sorry to be blunt and possibly rude. You have just invented that formula but not dervied it from first principles. Those papers I linked give some of the maths invovled in working ot lateral stiffness is complicated and computor models are needed. I say this and I used to be Physics and Maths teacher so my maths backgoround is strong and this something that would stretch my Maths skills to the limit and beyond and for that I will not bother to even try to work it all out.

Tension blance however does not effect wheel stiffness as Eric pointed out! That has been estabilshed many times (notice how it is not refered to in the paper only material properties of spoke and rim and bracing angles are concidered becase that is all that effects it) and yet you still cling to the idea.

What you have done is invented a ranking system for lateral stiffness which to me is meaningless and there are flaws in it.

I refer you again to this paper.
http://people.duke.edu/~hpgavin/papers/ ... -Paper.pdf" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

The answers you seek may be found by posting on Physics Forums. There are alot of very competant folk on there with Maths skills way beyond mine and yours (no offense intended) who could possibly help more with a matematical treatment of wheel stiffness.

I have been very blunt I am sorry if this offends.

However with 11 speed hubs (campagnolo have had them for a while now) shallow rims still work - I build them and have zero isses. Deeper rims ( for stiffness) and off centre rims (for tension balance and improving that never hurts) obviously help but I don't need maths to demsotrate that.

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