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what exactly is an asymmetrically-spoked wheel?

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what exactly is an asymmetrically-spoked wheel?

Old 09-09-08, 08:26 AM
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Disco Stu
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what exactly is an asymmetrically-spoked wheel?

Are they the ones where the spoke holes are off-set to the sides of the rim?
Or the ones where the rim itself is off-set?

Thank you

Last edited by Disco Stu; 09-09-08 at 08:36 AM.
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Old 09-09-08, 09:52 AM
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I've heard that term used in two different ways.

The most common today is with an asymmetrical rear rim in which the spokes are offest to the non-drive side.

Many machine built wheels are laced asymetrically with the pulling spokes heads in on one hub flange and heads out on the other hub flange.
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Old 09-09-08, 12:19 PM
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Originally Posted by Disco Stu View Post
Are they the ones where the spoke holes are off-set to the sides of the rim?
Or the ones where the rim itself is off-set?
Isn't that the same thing? The idea with placing the holes off to one side of the rim is to even out the spoke-angles between left & right sides of a rear-wheel (less dishing). But the rim you can still centre the rim between the dropouts.
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Old 09-09-08, 03:14 PM
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It could mean different types of spokes from one side to the other.
It could mean different lacing from one side to the other.
These are some tricks that builders have used to help alleviate the tension differential of the spokes on a rear wheel.

Al
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Old 09-09-08, 03:42 PM
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How is the "ERD" specified for an offset rear rim? I'm guessing you'd enter 2 different ERD values into a spoke calculation, and end up with your two different spoke lengths?
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Old 09-09-08, 04:27 PM
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Well, it depends upon the sophistication of the spoke-calc program. A lot of them are no more than look-up tables that required someone to have entered the correct ERD and correction-factors for left-right differences. A good spoke-calc program will ask for the left & right flange offsets from centre and then calculate the correct left & right spoke-lengths. You would then subtract the spoke-hole offset in the rim from the flange differences.
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Old 09-09-08, 05:30 PM
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Sorry to drag this along, but want to make sure I get it.

Ok, so if I was using http://www.bikeschool.com/spokes/ which I have many times, I calculate each side (drive, non-drive) separately. Suppose I end up with 282mm for DS and 284mm for NDS...

1) How do I determine the offset?
2) How do I apply that value to my resulting spoke length calculations?
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Old 09-09-08, 08:00 PM
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Thank you for the replies.

Manufacturers are claiming that it's SO good, so why don't they also do it on their deeper carbon rims?
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Old 09-10-08, 12:35 AM
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Originally Posted by smurf hunter View Post
Sorry to drag this along, but want to make sure I get it.

Ok, so if I was using http://www.bikeschool.com/spokes/ which I have many times, I calculate each side (drive, non-drive) separately. Suppose I end up with 282mm for DS and 284mm for NDS...

1) How do I determine the offset?
2) How do I apply that value to my resulting spoke length calculations?
1. to figure out your hub-flange offset, measure the following:

HUB OFFSET = (RightAxleLocknut to RightFlange) - (LeftAxleLocknut to LeftFlange)

Measure to the end of the locknut that meets the dropouts. This is the number you enter into #4 box in the spoke-calculator if you're using a normal rim.

2. If you're using a asymmetrical rim, subtract the rim-holes' offset from the hub-offset:

EFFECTIVE HUB-OFFSET = HubOffset - RimOffset


Basically, rim-offset counteracts the hub-offset giving more equal spoke-angles and spoke-tensions.
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Old 09-10-08, 04:00 AM
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Originally Posted by Disco Stu View Post
Manufacturers are claiming that it's SO good, so why don't they also do it on their deeper carbon rims?
The carbon rims wth high profiles usually tapers to a quite pronounced point. It'd be an entirely different engineering issue to offset the spoke holes on one of those as compared to merely offsetting the drill pattern on a sedately convex surface.
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Old 09-10-08, 09:22 AM
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Originally Posted by DannoXYZ View Post
1. to figure out your hub-flange offset, measure the following:

HUB OFFSET = (RightAxleLocknut to RightFlange) - (LeftAxleLocknut to LeftFlange)

Measure to the end of the locknut that meets the dropouts. This is the number you enter into #4 box in the spoke-calculator if you're using a normal rim.

2. If you're using a asymmetrical rim, subtract the rim-holes' offset from the hub-offset:

EFFECTIVE HUB-OFFSET = HubOffset - RimOffset


Basically, rim-offset counteracts the hub-offset giving more equal spoke-angles and spoke-tensions.
Makes sense now. Thanks.
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