maximum spoke angle?

gothicsurf

10 mW
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Jul 9, 2017
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Pacifica, CA
I am working on a spoke order for a Bafang SWXK hub motor in a 700c rim. Being one of the smallest motors, it seems like a good chance to go with 2x lacing with an angle less than 9deg (122mm flange diameter). The most used spokes in this case seem to be 13/14g Sapim Strong.

This angle is still about twice that of a standard wheel with 3x lacing. Would using the more rounded polyax nipples provide proper mechanical longevity or would using nipple washers be recommended?

2X front.jpg
 
That's not enough of an oblique angle to present a problem.

Lace the spokes all heads-in to maximize bracing angle and the wheel's resistance to side loading. Heads-out takes the too-narrow flange spacing of most hub motors and worsens it.
 
--> 'heads in' at the flanges sounds like excellent geometry.

would using polyax washers & nipples lead to a robust build, or would the benefits of this be negligible?
 
gothicsurf said:
--> 'heads in' at the flanges sounds like excellent geometry.

would using polyax washers & nipples lead to a robust build, or would the benefits of this be negligible?

Sapim Polyax nipples are my first choice because they're harder and more resistant to rounding off at high tension than DT Swiss.

I'd only consider using washers if your rim doesn't have eyelets, or if it's drilled for 12ga spokes. You don't have enough of an oblique angle to need any special treatment.
 
intended rim is a single-eyeletted 700c Mavic open sport .. sounds like I am good with just a standard build

is there a threshold at which one would want to start thinking about washers for higher angles?

are there any reasons one would chose standard Sapim brass nipples over polyax?
 
gothicsurf said:
is there a threshold at which one would want to start thinking about washers for higher angles?

The easiest way to determine this is to mock it up. Put the spoke and nipple you want to use into the rim you want to use, and see if it will gimbal to the angle you need. There are too many variables to get a trustworthy result any other way.

are there any reasons one would chose standard Sapim brass nipples over polyax?

I've only seen Polyax nipples from Sapim. Didn't know they made any other kind.
 
gothicsurf said:
This angle is still about twice that of a standard wheel with 3x lacing. Would using the more rounded polyax nipples provide proper mechanical longevity or would using nipple washers be recommended?

2X front.jpg

Definitely go with polyax nipples, the head is shaped like a ball joint and gives alot more angle as the spoke leaves the rim bed

You may want to drill the holes out about 0.5mm larger to allow the nipple to seat deeper and give the spoke more room to move

Here's a sur-ron rear wheel i did 3x cross with 13g spokes

https://i.imgur.com/y7w2wtQ.jpg
 
What are some good spoke calculator for normal wheelbuild?

I am playing around with this one because the graphics are good for a dumbfuck like me
https://www.prowheelbuilder.com/spokelengthcalculator/

Hoping to put my stock front hub on some new rims. Rear hub is probably f'd, and all my spares are 36h hub and rim is 32, its rough over here, real rough.

Strongest I think would be 3x for 32h, more lateral supports or whatevers
 
Tolkano said:
Definitely go with polyax nipples, the head is shaped like a ball joint and gives alot more angle coming off the rim bed

Not true. It's all a function of the rim hole diameter and depth versus the spoke nipple diameter. Conical head, spherical head, makes no difference.

I like Sapim Polyax nipples, but they don't offer any more angle out of the rim than DT Swiss nipples. DT Swiss makes spherical headed nipps called "Prohead", but they didn't catch on because it doesn't matter.
 
calab said:
What are some good spoke calculator for normal wheelbuild?

I like http://leonard.io/edd for normal wheels.
 
For the sake of being thorough, if planning for elbows out throughout, would it be more correct entering the flange distance as that between the outside edges as opposed to using center of flange? My experience is that most wheels alternate elbows in and out on each side for leading / trailing spokes respectfully, but would calculations be more accurate here with this modified input?
 
gothicsurf said:
For the sake of being thorough, if planning for elbows out throughout, would it be more correct entering the flange distance as that between the outside edges as opposed to using center of flange? My experience is that most wheels alternate elbows in and out on each side for leading / trailing spokes respectfully, but would calculations be more accurate here with this modified input?

If you want to compensate for that factor, use the outside to outside flange width instead of center to center.

If for some reason you lace all inside the flange instead of outside, then use the inside flange spacing.
 
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