2 cross lacing

[Polar Bear]

Can anybody point me to an online vuide please?

Not only am I failing miserably with this but I'm failing miserably with google and youtube fu.   

[Kim]

It's just like three-cross but without the first cross.  You 'lace' the final crossing.

Sheldon's page is the only wheelbuilding reference I've ever needed.

[Polar Bear]

Indeed but it aint wprking.   Or at least, I'm probably doing something stupid.

[Ian H]

2x is 7-span.  A pair of adjacent crossing spokes should end up 7 holes apart at the rim (or 5 free holes inbetween them).  Which may or may not help.

[mzjo]

What's the problem? If the spokes are the right length building is the same as any other cross (except crowsfoot and weird things like that). Is this with the heavy gauge spokes?

[Polar Bear]

I wish I knew what the problem is.   I just cannot figure it out for the life of me.   The leading spokes go fine but as soon as I lace in one side of the training spokes it's all gone to cock.   It's like the spokes are too long, but they are not.     

I have measured everything a dozen times.   It's bizarre to the point of totally stupid. 

I think that the only way to resolve this is to take it to the lbs and pay somebody to relieve the immense stress that this is causing me.   It'll just have to wait now until we get back from Scotland.

[Kim]

Sure it's not a maths cockup?  That's the hardest part of building wheels.

[Polar Bear]

Yup.  I'm sure because somehow, and I really don't know how, suddenly it's there.

I have stripped and re-laced this a dozen times but this time i must have done something differently.   I really don't know what.

Man.   I need a shower!   

Where's the emoticon for immense relief? 

[rogerzilla]

If you lace one side at a time, like I do, the first spoke in the second side is the most critical one.  Easy to get it wrong.

Brompton wheels are supposed to be x2 unlaced but I've built them both ways with no issues and prefer laced.

[Brucey]

If you have even the slightest doubt, tell us what rim spokes and hub you are using, and someone will run the numbers through a spoke calculator and check it is going to work for you.

cheers