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· Just Riding Along
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I'm going to skip over the theory and go right to my bottom line: I have one rear wheel built with 14 ga DS and 15 ga NDS. The wheelbuilder prefers straight gauge spokes. It's been a stable, trouble free wheel.

I have a fixed gear rear wheel (no dish) built with 14 ga on both sides It's been a stable and trouble free wheel. (I bought it used; it came that way. Had it been up to me, I'd have spec'd 14/15/14s.) Both use DTSwiss spokes and are Open Pro rims on D/A hubs (road and track.)

I have another rear wheel built with a 105 hub, an MA3 rim and 14/15/14 ga spokes, both sides. (EBay purchase for older bike rebuild.) It has required more truing than the others. However, it has lower quality spokes (unknown brand, offshore source). All my wheels use brass nipples.

I suspect the cheap spokes are the source of my problem with the 3rd set of wheels and that, possibly, the MA3 rim flexes more than an Open Pro, allowing the wheel to go out of true.

A 14/15/14 spoke should be more than adequate for a rear wheel. If you like straight gauge spokes, the 14 DS, 15 NDS approach is perfectly valid. Either way, if you approach or exceed 200 lbs, get 36 spokes.
 

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eddie m said:
I can't prove it, I'm not sure how to analyze it and I don't want to do any destructive testing, but I think that it's true that the wheel gets more unstable as it flexes to the drive side.
As the rim flexes towards the NDS the spokes will go slack with less of a load than towards the DS. The difference is pretty huge. This is easy enough to show by laying down the wheel and pressing on the rim. Having lighter NDS spokes means they will move a farther distance before going slack, but since they are also less stiff, it takes about the same amount of force.
 

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rruff said:
As the rim flexes towards the NDS the spokes will go slack with less of a load than towards the DS. The difference is pretty huge. This is easy enough to show by laying down the wheel and pressing on the rim. Having lighter NDS spokes means they will move a farther distance before going slack, but since they are also less stiff, it takes about the same amount of force.
I'm not sure what that means for the stability of the wheel. Judging by the different solutions to the problem (radial on one side or the other, more right side flange offset or less right side flange offset) I'm not sure anyone knows exactly the best way to insure lateral strength and stability, as opposed to stiffness. It seems like the kind of problem everyone should come to the same solution on, but apparently they don't.
That's why I stay with fairly conventional wheels. I don't use your solution of choosing a hub that is offset farther on the right side because I don't understand whether that makes it more stable or just stiffer. I don't know how to analyze that problem either.
em
 

· A wheelist
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eddie m said:
I'm not sure what that means for the stability of the wheel. Judging by the different solutions to the problem (radial on one side or the other, more right side flange offset or less right side flange offset) I'm not sure anyone knows exactly the best way to insure lateral strength and stability, as opposed to stiffness.
That's why I stay with fairly conventional wheels.
em
Are some people looking for solutions to problems that never existed in the first place? How many wheels collapse sideways because they have spokes of the same number, cross and gauge plus flanges of equal diameter on both sides of the wheel? None?

I've been building mine like that for 46 years and it ain't happened yet. It's probably best to just get out and ride.
 

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eddie m said:
Judging by the different solutions to the problem (radial on one side or the other, more right side flange offset or less right side flange offset) I'm not sure anyone knows exactly the best way to insure lateral strength and stability, as opposed to stiffness. It seems like the kind of problem everyone should come to the same solution on, but apparently they don't.
Manufacturers come up with different "schemes" just to be different. So long as it isn't really stupid, it will generally work fine. Some of them *are* stupid, though...

It is no great trick to build a wheel that will work well, but when you wish to optimize the strength/weight/aero/cost relationships there is less margin for error. Factory wheels are usually not very light, so it is easier to make the wheel strong enough for most riders. IMO triplet lacing is a good choice if you have a stiff rim, except for what happens when you break a NDS spoke. But then conventional lacing works quite well also...
 

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Mike T. said:
Are some people looking for solutions to problems that never existed in the first place? How many wheels collapse sideways because they have spokes of the same number, cross and gauge plus flanges of equal diameter on both sides of the wheel? None?

I've been building mine like that for 46 years and it ain't happened yet. It's probably best to just get out and ride.
It's not about looking for problems, it's about finding the best solutions. You can do what you always did, but sometimes it's worth looking for even small improvements. And I've seen wheels collapse, so it's not entirely a theoretical exercise.

em
 
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