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PostPosted: Tue Feb 26, 2013 5:08 am 
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bm0p700f wrote:
The best way to analayise a wheel is with FE anaysis anyway and that require a computor.


That's cool. :beerchug:

But.. not in my world. :thumbup:

I'll continue to build and test my own ideas.


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Posted: Tue Feb 26, 2013 5:08 am 


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PostPosted: Tue Feb 26, 2013 8:36 am 
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Location: Glermsford, Suffolk U.K
tortional stiffnes was testsed but not data given. Tortional stiffness reflects torque effects in combination with lateral stiffnes. If these really did not change when spokes are tied and soldered then it has no effect. I can believe the results even if there is no data as it seems reasnable. Data would be nice though. Maybe it is published somewhere.

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PostPosted: Wed Feb 27, 2013 9:10 pm 
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KLabs wrote:
Hi WinterRider, you know what you could try ... how about a 32H hub (of your choice) done as a 28H rim 16:12 3xDS and the NDS well (minus 4 spokes) could be done in a few different ways and even mixes (like radial mixed with 2x) :)

What do you think :)


I ran thjs scenario this morning using the measurements from a Shimano 5500... NDS tension would be 100 kgf given DS at 120.

Might.. be worth a looksee.


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PostPosted: Thu Feb 28, 2013 1:43 am 
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Hi WinterRider, that's excellent ... 120kgf xDS 100kgf xNDS (1200/1000N) ... 83% ratio :)

What hub specs was that with, such as DS/NDS Spoke Circle Ø, F.T.F spacing, L.C.F (NDS offset), R.C.F ((DS offset) :)

What lacing are you thinking of ... 3xDS 3xNDS, 3xDS 2xNDS, 2xDS 3xNDS, or ?xDS ?xNDS ... 16H flange should give perfect spoke symmetry (I think so even NDS ???) :)


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PostPosted: Thu Feb 28, 2013 2:42 pm 
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KLabs wrote:
What hub specs was that with


The Shimano 5500 specs according to Edd are 45 for flanges.. 32.5 left.. 20.5 right with 2.6 holes. Those are reliable I believe.

I haven't laid for a lacing yet.. likely 3x DS with NDS between each of the eight triangles.. the remaining four NDS could be radial spaced outside of those triangles at every other one.

This scenario shows how much hub stats affect NDS lacing tension. I was surprised to see a 33% increase in that tension by only eliminating four spokes.

What lacing do you favor?


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PostPosted: Fri Mar 01, 2013 8:45 am 
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WinterRider wrote:
KLabs wrote:
What hub specs was that with

The Shimano 5500 specs according to Edd are 45 for flanges.. 32.5 left.. 20.5 right with 2.6 holes. Those are reliable I believe.
I haven't laid for a lacing yet.. likely 3x DS with NDS between each of the eight triangles.. the remaining four NDS could be radial spaced outside of those triangles at every other one.
This scenario shows how much hub stats affect NDS lacing tension. I was surprised to see a 33% increase in that tension by only eliminating four spokes.
What lacing do you favor?

Hi WinterRider, I will have a think about the lacing, but in the meantime, perhaps we both can think about it :)
Do you mind doing your Edd simulation with say a DT Swiss 240S rear hub ... is that possible and would that be ok ... thanks :)
Also, using Edd how can you independently change DS/NDS spoke counts to obtain a NDS/DS tension ratio ...

Perhaps bm0p700f, eric, Zen Cyclery, or others, might like to also provide some options ... thanks :)


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PostPosted: Fri Mar 01, 2013 9:48 am 
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I see most Powertap wheels being built with the pulling spokes heads out. Is this because the pulling spokes (left side of the hub) are more in line with the middle of the hub ?


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PostPosted: Fri Mar 01, 2013 11:26 am 
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KLabs wrote:
Do you mind doing your Edd simulation with say a DT Swiss 240S rear hub ... is that possible and would that be ok ... thanks :)
Also, using Edd how can you independently change DS/NDS spoke counts to obtain a NDS/DS tension ratio ...


Edd shows 52% NDS tension with a 32 hole DT Swiss 240S. To arrive at left side kgf for 12.. to date I've used the left side ratio times the kgf for the right in 32H format.. and then divided by the spoke number left. Has been accurate for what I have assembled.. with some adjustment for all outbound or inbound spokes NDS.

The DT Swiss scenario gives 62 kgf NDS for a normal laced 32H.. goes to 83 kgf lacing 12 left... assuming 120 DS tension.


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PostPosted: Fri Mar 01, 2013 11:57 am 
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WinterRider wrote:
Edd shows 52% NDS tension with a 32 hole DT Swiss 240S. To arrive at left side kgf for 12.. to date I've used the left side ratio times the kgf for the right in 32H format.. and then divided by the spoke number left.
Has been accurate for what I have assembled.. with some adjustment for all outbound or inbound spokes NDS.

The DT Swiss scenario gives 62 kgf NDS for a normal laced 32H.. goes to 83 kgf lacing 12 left... assuming 120 DS tension.

Hi WinterRider, interesting and exciting ... (120 * 0.52) * (16/12) = 83.2kgf :)

Lets workout a lacing we would like to try and build it (with your 5500 hub) :)


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PostPosted: Fri Mar 01, 2013 1:47 pm 
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Shimano 7900 rear FH.. can anyone confirm the hub stats for building?

1. Shimano Dura Ace 7900, rear

Left flange ⌀: 44 mm
Right flange ⌀: 45 mm
Centre to left: 34.5 mm
Centre to right: 18.5 mm
Spoke hole ⌀: 2.4 mm

2. Shimano Tech Doc states:

FH-7900 52.8/53.8(L/R) @130MM DS--20.15MM NDS--36.35MM

These discrepancies.. one wonders.


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PostPosted: Fri Mar 01, 2013 11:39 pm 
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Hi WinterRider, found this ... http://www.kstoerz.com/freespoke/hub/92 ... http://www.kstoerz.com/freespoke/fullcalc

Shimano DA7900, Rear, 10mm, Shimano 8/9/10/SRAM, 130mm OLD, Labyrinth and contact seals, 254g
Spoke Hole Dia = 2.5mm
NDS (Left)
Flange Spoke Hole circle = 44mm
Flange Offset (CLF) = 34mm

DS (Right)
Flange Spoke Hole circle = 45mm
Flange Offset (CRF) = 18mm

It would appear for an ISO 622mm rim
- that NDS brazing angles of >=6 degrees are sufficient (but closer to 10 degrees is better although this lowers NDS tension)
- that DS brazing angles are about 3.7 degrees (ERD 580mm), but a DS brazing angle >=4 degrees can be achieved using Rim ERDs <=535mm or OC rims


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PostPosted: Sat Mar 02, 2013 1:28 pm 
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KLabs wrote:

- that NDS brazing angles of >=6 degrees are sufficient (but closer to 10 degrees is better although this lowers NDS tension)
- that DS brazing angles are about 3.7 degrees (ERD 580mm), but a DS brazing angle >=4 degrees can be achieved using Rim ERDs <=535mm or OC rims


I can't find any advanced in-depth links to the value of bracing angles. Anyone with some links?

I question the value of lowering spoke tension.. for instance on the NDS just to achieve a minor improvement in angle. I haven't read much concern for the small angle on the DS.. I assume given the spoke tension.

IMO a symmetrical or near symmetrical spoke tension on the rear is more desirable. Higher spoke tensions within reason means greater durability of the wheel.


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 Post subject: The wheelbuilding thread
PostPosted: Sat Mar 02, 2013 3:09 pm 
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WinterRider wrote:
...
I can't find any advanced in-depth links to the value of bracing angles. Anyone with some links?

I question the value of lowering spoke tension.. for instance on the NDS just to achieve a minor improvement in angle. I haven't read much concern for the small angle on the DS.. I assume given the spoke tension.

IMO a symmetrical or near symmetrical spoke tension on the rear is more desirable. Higher spoke tensions within reason means greater durability of the wheel.


While I've been following your theoretical discussions with some interest, your above statement really got me scratching my head saying to myself "really, you need 'advanced in-depth links to the value of bracing angles'". Isn't that just obvious and so easy to prove to yourself even with the simplest of scientific apparatus. I think your obsession with the be all and end all of a good wheel being high and equal DS and NDS tensions is getting a little bit like, well, an obsession. Not saying you should stop exploring it cuz that's clearly not going to happen :). Take the extreme cases for example. Imagine a wheel with zero bracing angles and the spokes go straight up into the rim. Put all the tension you want on these spokes (and lets for a moment assume the rim, hub and spokes can all withstand this tension). Now imagine a second wheel with a decent amount of bracing angle on both sides (a front wheel for example) with much much less tension on the spokes. Which wheel, when a heavy lateral force is applied at the rim do you think will want to collapse first. I suspect it might be the first wheel. Why is that? I suspect it is because of the zero bracing angle. The second wheel will resist collapse, even though the spokes are at much less tension, because they have at least some bracing angle. Maybe I'm missing something, but that's what common sense says to me.

A standard 32 spoke 3x rim like the ones I've been building lately (Campy record hubs, Nemesis rims) have only 44% NDS spoke tension relative to the drive side yet seem strong as all get out. I absolutely love riding these wheels and feel more confident at high descending speeds on a technical descent than I do on any of my fancy carbon hoops. And as much as I like the "G3" or 2:1 spoke pattern on these wheels I did manage to pop a spoke last week on one of my rear Bora Ultra Twos. But that was a first and no biggie. Just replace the spoke and off I go. Unlike say, a Lightweight where if I damage a spoke it would take a fair amount of time to get it back from repair before I would be up and running again. Sometimes there's a lot to be said for the tried and true. Ok, that's all.

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PostPosted: Sat Mar 02, 2013 4:35 pm 
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Mr Calnago in my view we're all allowed our various interests and opines. I do not judge yours.. I suggest that attitude allows for everyone's thinking.. right, wrong, or different.

Bracing angle.. how much of this 'high tech' wheel building is splitting hairs?. I read in these papers minimal percentage gains attributed to various width's, spoke diameters et al. Reviewing the lateral stiffness testing shows a world of difference is measurements.. and in the end a wheel not measuring on the low end of the subject goal performed well for the desired outcome in real world conditions. Hubs stats range in bracing angles... all of them appear to perform fine given a sound build.

Computers.. et al is fine and of value. Mount the tire.. ride said wheel with some significant load.

Maybe the "obcession" with bracing angles.. is just that. :P


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PostPosted: Sat Mar 02, 2013 7:18 pm 
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Location: Glermsford, Suffolk U.K
Spoc calc (the excel version) will work out the bracing angle and tension balance for you although it is not set up for triplet designs.
NDS bracing angle is very important. The DT Swiss 240 road hub has short NDS flange to centre spacing. The Miche RG2 hb has similar PCD and DS flange spacing but wide NDS flange spacing. Built a wheel with the same spokes and rim on the two hubs and the wheel with the Miche hub has signifiicantly more lateral stiffness.

The miche hub will give a tension balance of 44% but is stiff. The DTSwiss 240 hub will give a tension balance of 50 or 52% with the rim I used but is like a bloody noodle - it's hopeless. So much so infact I will only use the 240 hub now with deep V- section rims like the RR585 or with shallow depth rim for low power output riders and then only in 32H drilling with Race spokes or similar.

So bracing angle is more important than tension which is why my wheels with the miche hub and very low NDS tension work. If I had biuilt the wheel with the 240 hub I would have broken spokes by now I am sure as well as rim hitting pads all the time I aply even moderate torque.

If you want equal tension ride a flip flop or a fixed wheel bike.

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Posted: Sat Mar 02, 2013 7:18 pm 


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