Wheelbuilding / Wheel Building / Wheel build help

done, thanks.

im building my first wheels and im wondering how much tentions there should be on the spokes?

lots

A above middle C

Does this look just a little bit odd?

Yes. Those cushions don't suit the sofa at all.

Yes. Those cushions don't suit the sofa at all.

Haha, i know it was for chrismas..
I was talking about wheel....

Does this look just a little bit odd?

Could be an optical illusion but it looks like the spokes go from drive side on the hub to non drive side on the rim. That would be odd.

edit: ignore, found way to view image again, not what I thought

It's hard to tell just from the photo as digital cameras sometimes warp sraight lines / curves.

Maybe the spokes need to be bent around each other slightly where they intersect and bit more tension all round. There seem to be a lot of curves where there should be straight lines.

But this could just be the picture...

Are you concerned about anything specifically?

im building my first wheels and im wondering how much tentions there should be on the spokes?

lots

Or, to be a little more helpful:
A wheel holds you up by compressing (reducing the tension in) the spokes near where it touches the ground. Several failure modes result from spokes going slack so using more tension to start with helps avoid that, but there are limits and trade-offs. With enough tension you can overcome the strength of the rim and it can spontaneously pringle. This is easiest with large diameter, thin, shallow, light weight rims with lots of spokes*. Jobst Brandt's theory is you should get close to this point then back-off a little, but recognising that is not for a first time.

Increasing spoke tension makes it ever harder to turn the nipples and the spokes twist more as you work, so it gets harder to make accurate adjustments and more likely you'll leave spokes twisted (causing the wheel to go out of true when ridden). Lubrication helps. Plain gauge spokes twist less, but are otherwise worse than butted.

*I did it on the first wheel i ever built - a 27" 36h rim that ticked all the other risk boxes too.

Does this look just a little bit odd?

Could be an optical illusion but it looks like the spokes go from drive side on the hub to non drive side on the rim. That would be odd.

This. Around the valve hole it looks like you have a pattern of 2 spokes to one flange, 2 to the other. Opposite the valve hole it looks ok - alternate rim holes have spokes from alternate flanges.

A above middle C

I don't get this standard 440Hz theory. It seems to imply that all spokes of the same length should be placed under the same stress and strain, as if the material limits of the spoke are what determine its appropriate load.

But if the limit is set by the rim then there is a budget of tension to be shared among however many spokes there are. Even assuming equal numbers of spokes, thinner butted spokes require higher stress (so higher notes) to generate the same tension*.

If you look at changing wheel size the theory gets even worse: larger diameter rims can withstand less tension, but tension would have to rise with square of spoke length to maintain the same note!

(The frequency of the fundamental note of a string is f = v/2l, where l is the length and v is the velocity of transverse waves on the string. v = sqrt(T/da), T tension, d density, a cross-sectional area. Solve for T = da(2lf)^2, or write stress o = T/a, then v = sqrt(o/d), f = sqrt(o/d)/2l )

• I think it's slightly misleading that (e.g.) Sapim advertise the strength of their spokes in Newtons/mm^2, not Newtons. Newtons/mm^2 tells us how clever they are at getting more strength out of steel. Newtons would tell us how strong their spokes actually are. Just for kicks, i did the sums:
  [code]
  spoke strength dimensions area strength
  / N/mm^2 / mm / mm^2 / N
  cx-ray 1600 2.0, 2.3x0.9 ellipse, 2.0 1.63 2600
  cx 1200 2.0, 2.8x1.3 ellipse, 2.0 2.86 3430
  laser 1500 2.0, 1.5, 2.0 1.77 2650
  race 1350 1.8, 1.6, 1.8 2.01 2710
  2.0, 1.8, 2.0 (standard?) 2.54 3440
  strong 1400 2.3, 2.0 3.14 4400
  leader 1080-1180 1.8 2.54 2750-3000
  2.0 (standard) 3.14 3400-3700
  2.3 4.15 4490-4900
  2.6 5.31 5730-6260
  2.9 6.61 7130-7800[/code]
  Although the N/mm^2 values are more closely linked to how much strain (stretch) the spokes can take which might be a more important consideration. And fatigue life should matter a lot too.
  

Around the valve hole it looks like you have a pattern of 2 spokes to one flange, 2 to the other. Opposite the valve hole it looks ok - alternate rim holes have spokes from alternate flanges.

Looking again i now think the weirdness goes all the way round. I assume it's intentional - are you showing off, or is there some method to your madness? Did you have to use different length spokes for each side?

I don't get this standard 440Hz theory.

Sarcasm recognition fail

I was giving the question the answer it deserved, and your subsequent answers have gone a long way to explaining the deficiencies of the question.

As a matter of idle curiosity, what range of notes does your set of equations yield, starting from the ~300mm plain guage spokes in a Dutch bike, which will probably work fine with 500N tension since there are 36 spokes sharing the load, up to the ~200mm CX-Rays at 1250N in something like a Zipp 1080?

Should have realised, but was suffering from having seen that theory quoted in earnest in the past.

As for your question, the answer is about a factor of 10, from around 240Hz for the Dutch bike, to over 2400Hz on your short cx-rays.

Looking again i now think the weirdness goes all the way round. I assume it's intentional - are you showing off, or is there some method to your madness? Did you have to use different length spokes for each side?

Same lenght spokes in both sides. Yea, it was fuck'd up..When one spoke went wrong way and I followed same pattern and the rest is in there.
I will give it a new try. Is this so far build ok? - This time I want to be sure and make it right, so it good to ask now.

Is this now ok at this far?

The way you've shown it, the valve is trapped between spokes. Twist the hub the other way.

The way you've shown it, the valve is trapped between spokes. Twist the hub the other way.

Do you mean clokwise? (away from the valve hole)
I haven't twist the hub yet so I think all is ok so far..I think.

Edit:
I just atached few spokes more in the other side. (Over-over-under) I painted quikly those (3) atached spokes in red because they maybe stands out bit more.
Looking Ok at this far?

Hi LRM

http://www.sheldonbrown.com/wheelbuild.html

For your question above scroll down to "key spoke" onwards (noting spoke count adjustment above it).

It might be a good idea to use this as a primary source. There's a lot of knowledge on this forum but you'll build a better/safer wheel if you work from one definative source that speaks in the same voice / manner / terms regarding every job at hand.

After that all the knowledge on the forum will probably be more useful as you bring it all together. Look forward to seeing the progress, good luck!

^^ looks right so far.

Can anyone tell me whether building a black Shamal track rim 16H to a Dura Ace 7850 front 16H hub is possible or a good idea?

16h rim & 16h hub should to together surely? Purists may not like the Shamal / DA combo tho?

^there an informative thread on WW on the topic of reusing 90's Shamal rims.
Spokes and nipples and nipple support beds and the tool to access the nipples in the rim all "seemed" to be proprietary designs, but some claim to have made usable wheels out of them with OTP components whilst others disagree.

Crosspost from Polo thread.

I'm having a new polo wheelset built, and my parameters are as follows.
26", 36 holes.
Strength (specifically for side impacts).
As small gaps as possible to stop balls going through.

So i've come up on a variation of 3x and crow's foot, and it meets the small gaps, but I'm not sure how strong it will be, or if it is even a good idea. Any thoughts?

This looks potentially interesting, a cross between 3x and crow's foot.

I don't know much about wheelbuilding, but it certainly has smaller gaps, but would it have the strength of 3x? I guess having two spokes from the same side of the flange crossing so close to the hub isn't a good thing though.

Normal 3x