2-cross lacing- why...
 

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[Closed] 2-cross lacing- why over/under?

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Just lacing up my first 2-cross j-bend wheels, and I'm just curious about the crossing being over then under- it seems to need quite a lot of deflection to create the "under" crossing, the wheel definitely wants to be over/over (because both of the spokes it crosses are on the other side of the flange) I suppose it's not really any different from 3-cross but it feels it, somehow. But the advice seems pretty unanimous that it should be this way.

I've built it that way because I just do what Roger tells me but if anyone knows why, I'd be interested.


 
Posted : 19/07/2020 6:55 pm
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Same with all builds (apart from radial obviously...), they all do at least one under. 3X are over, over, under.

The spokes need to be touching and braced against one another to transfer and spread the loading.

If it helps at all, there's always a fair bit of spoke bending required in the latter stages of the build to get the spokes to thread through where they need to go.


 
Posted : 19/07/2020 7:15 pm
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Never really thought about it while building, I always thought of it as 3x without the cross closest to the hub not the other way arround.

Do the spokes have to touch? Motorbike, car wheels arent built like that, neither are straight pull bike wheels.


 
Posted : 19/07/2020 7:46 pm
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crazy-legs
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If it helps at all, there’s always a fair bit of spoke bending required in the latter stages of the build to get the spokes to thread through where they need to go.

Yeah, maybe it just feels bigger because of where the under crossing is.


 
Posted : 19/07/2020 7:57 pm
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It pulls the spokes swaged end against the flange so they are locked in place.

A j bend isn't perfect under tension because there is scope of it moving side to side on the tiny flat section.

Whereas straight pulls can centre in a countersunk socket.


 
Posted : 19/07/2020 8:02 pm
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Do the spokes have to touch? Motorbike, car wheels arent built like that, neither are straight pull bike wheels.

You get straight pull wheels both ways, some manufacturers spokes touch and some dont.


 
Posted : 19/07/2020 8:07 pm
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Wonder if it stops the wheel distorting under braking/acceleration as it means the loads on both sides are closer to symetrical regardless of whether you have the braking/accelerating spokes insider or outside.


 
Posted : 19/07/2020 9:43 pm
 Aidy
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Brandt says:

Spokes in a crossed pattern are usually interlaced at their last crossing before reaching the rim. Spokes coming from between the flanges are laid over those from outside the flanges. Interlaced spokes take up each other's slack during severe radial loading and reduce the chance of spokes becoming loose. If spokes become loose, their nipples can unscrew. Radial spokes cannot be interlaced and therefore, lose alignment from road shock more easily. Interlacing also gives more clearance between the spokes and the derailleur on rear wheels.


 
Posted : 19/07/2020 11:48 pm
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I'd always assumed it was to help disperse stress/load more evenly around the rim, but have never looked in top it to find out of my thought process was close or not.


 
Posted : 20/07/2020 8:33 am
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THanks folks, all makes sense! I'd never really thought about it til this wheel


 
Posted : 20/07/2020 9:37 am

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