building a wheel spokes at weird angles
 

http://bikeforums.net/attachment.php...hmentid=376466I put in figures in a spoke calculator online for the hub and rim, but initial lacing up the angles look weird. Should I continue?

#1 Wheel Building SPOKE CALCULATOR Now Online | PROWHEELBUILDER

Using this calculator, nuvinci n360 32h rear on 26 inch Alex rim should be 234.9mm, and I ordered 234mm spokes

Looks fine to me. Look at a completed wheel and you'll see that all the spokes are at an angle.

You're crossing the spokes, right? How did you think they were going to get across each other?

Im mainly worried about the angle they make with the rim. All of my other wheels have the spoke making a 90 degree angle with the rim. Then, on a hub this big I'm not sure if it is possible to have it 90 degrees.

I'm also starting to think I made a mistake assuming 2-cross. For a hub this heavy maybe 4 cross is a better idea.

You need to read up on wheel building. Cross number has absolutely nothing to do with hub weight. Cross number is chosen only for the purpose of arranging the spokes at exactly the tangent angle to the hub that you show in your photo. That allows the hubs to pull the rim around with the greatest efficiency. The larger the flange, the fewer the crosses. The smaller the rim diameter, the fewer the crosses. The more spokes, the greater the crosses. With a hub that large, you are likely limited to 2X at a normal number of spokes.

Only radial spokes which aren't used to drive a wheel will be radial to the rim. Any crossed spokes must approach the rim at a smaller angle to the tangent.

Spoke crosses likely makes for a stronger wheel though, no? With a hub this heavy, I probably want as strong a wheel as possible

You probably could have gone to 3-cross, but that would have made the problem worse. Large hubs- 2 cross is fine...

if you were to go to four cross
the angle would be even more severe
when i laced my twenty six inch alfine wheel last year i went with three cross
as it had been laced into a 700c rim
and i am mildly unsatisfied with the angle at the hub
so if i ever re lace it i will go with two cross

the reason yours looks so weird at the rim is because you only have spokes in one side of the hub
put the first set into the other side of the hub and the rim will be pulled toward the centre and have less of an angle when viewed from the side

the weight of the hub does not add any stress to the spokes
so need not be considered when designing the wheel

Yes spoke crossing does make for a stronger wheel , it why most wheels are built as 3 cross .

Hmm, well apparently they recommend a 1x pattern. Lacing Question: all spoke heads in?

No, not really. And you don't have a choice to cross spokes more than they can. It is self limiting.

No that is not true. Most wheels are 3X because the rim and hub sizes and spoke number make 3X give tangent spokes. If the number that resulted in tangent spokes were 2X, that is what would be used. Yes, you can choose lower numbers of crosses than the proper number, but that is hardly ever done. Not because of strength, but because of the desire to have the spokes tangent to the hub.

I have a personal guideline for 700c wheels where I try to keep the separation of the two parallel spokes no more than 3" or so at the hub. That means reducing the number of crosses when using ultra large flanges. By the same token, smaller rims call for smaller separation at the hub.

If you want a rough guideline, keep spoke separation at the hub smaller than the 1.5x the distance between the same spokes at the rim, preferably nearer to 1x that distance.

But it .
is true for the rear wheel

Do you have documentstion for that? The point is you want the driving spokes to be tangent to the hub circumference. Once you have that, more is not better. Take a tandem wheel with 40 spokes for example. Yes you use 4X commonly, and yes it is a strong wheel. But that is be ause of 40 spokes not 4X. The 40 spokes just happen to demand 4X.

The tangent spoke combinations are 4x/36, 3x/28 and 2x/20 Most wheels are 3x on 32h wheels because that's as close to tangent as possible, and 4x would be beyond the centerline.

Tangent spoking (it's still called tangent even if it's really secant spoking) is needed for hub to rim torque loads. Truly tangent means the smallest change in tension for any given torque load, with things getting progressively worse as the spoke line of action passes closer to the axle.

Obviously, front non/disc wheels don't benefit from tangent spokes, but the hub flange might if it isn't designed for radial.

here some reading for you , repenmanparker .http://sheldonbrown.com/wheelbuild.html

Thanks for that detail. Your "tangent" combinations correspond to shallow 700C rims and small flange hubs, right. Deeper or smaller rims, and/or higher flanges would all reduce the number of crosses that give spokes tangent at the hub. Correct me please, if that is incorrect. I am always trying to get it right.

let's start with the basics and go from there.

Tangent means at right angles to the radius. So a (truly) tangent spoked wheel will have the parallel spokes coming from adjacent holes in the rim meeting the hub at the centerline 180° apart. Rim size has little to do with this, it's about how the spokes leave the hub. Those combinations I listed before are the ones that meet the test. As a rule, add/subtract 1 cross for every 8 holes.

Since the parallel spokes aren't truly parallel, they're not perfectly tangent, but they're as close as you're going to get. Perfectly tangent spokes would happen when the distance between two spoke holes in the rim is equal to the hub flange diameter, and the parallel spokes actually are. However, that might mean rough angles at the rim which is what the OP is worried about.

Would a non-disc front wheel benefit from tangent lacing under braking strains?

It's all about the angles rather than number of crosses. As you said, ideally you'd like for the spokes to enter the rim at a 90 degree angle but be tangent to the hub. You can't have both so you have to compromise. In general larger diameter hubs = fewer crosses. I'm thinking 2 cross for this build is going to work out just fine.

Only if non-disc include drum brake hubs. Non-brake hubs cannot have any net torque loads because they spin freely on the ball bearings. According to Newton's third law, you cannot have a force if there's no ability to resist. (in this consider the inertia of the hub shell to be zero).

However, there is a benefit to tangent spoking on rim brake front wheels. Interlaced spokes provide degree of resilience that radial spoke lack. This reduces shock stress at both the hub and rim.

+1

Also consider that torque considerations are related to the spokes line of action and how far from the axle it passes. Often 2x or even 1x on a very large flange passes farther out than the diameter of a small flange hub.