Help needed from wheelbuilders for 24 spokes on 36 hole hub.

[bricky21]

Anyone have any updates on this? I've got a Planet X 20mm rim (24h) and a 36h White Industries eccentric ENO hub (36h) in my garage somewhere so i thought i'd see if i could have a go at a project to keep me interested over the winter.
Would love to know how Bricky got on with his design. My preference would probably be a 6 NDS, 18 DS with 2-cross just as it looks the simplest to build up but if the 12-12 design works well i might have a go at that.

I built the wheel but never actually rode it because I'm switching to Campagnolo and can't fit the Wheels Manufacturing cassette on that particular hub.
It was difficult to come up with the 6 NDS crossed spoke lengths. In the end I mocked up the wheel to scale with the same geometry program I used to come up with the lacing pattern. It gave me the distance from the ERD to spoke hole, so all I needed to do was apply the pythagorean theorem and bingo I had my spoke length. I tried a few other methods but either they were flawed or I was doing them wrong but the spoke lengths were way off.

I can't think of any reason why it wouldn't work just as well as a standard 24 hole wheel. The rims are stiff and strong, spokes are strong, and the hub has good geometry, so what could go wrong.

[JamieL]

It was difficult to come up with the 6 NDS crossed spoke lengths.

That's pretty much why i thought i'd go with 6 radial spokes on the non-drive side. Been playing around with the pattern on the DS. The best one i've come up with so far is something like this:

Where the red lines and the inner circle are the NDS and the blue lines and the outer circle are the DS. The alternating coloured spoke holes are because the rim is offset drilled.

Think i should be able to work out the NDS lengths pretty easily and if i get another quiet day in the office i'm sure the DS lengths shouldn't be too hard...

[bricky21]

Something doesn't look right with your wheel. I think if your going to try the 18-6 pattern you really need to do the crows foot on the DS. I drew up that pattern, and posted it in this thread somewhere. The other question is how would your wheel cope with 1 of six spokes breaking if and when that happens. It's my understanding that to build a really good 2:1 spoked wheel you'll need a lot of NDS offset, and the 18-6 is actually 3:1 so in my mind you would want even more NDS offset . Also if you are capable of figuring out the DS spokes on the wheel that you drew up(there are two different lengths) then you could figure out the spokes for the NDS crossed in the 12-12. If you read threw the thread from beginning to end I think you'll see that the 12-12 pattern that I eventually came up with really is the most sensible option.

one last thing...I don't think you can properly build a 2:1 or 3:1 wheel with an offset rim. It must be center drilled.

[JamieL]

I think you're probably right about 12-12 being the best, i was just trying to make it a bit easier but the more i think about it, the more i think there are two different DS spoke lengths which my quick drawing doesnt really show.

Regarding building a 2:1 wheel on an offset rim i agree that's a bad idea but a 3:1 (in this case) would mean all NDS spokes are in the same plane. the offset probably wouldn't be enough though as you've pointed out...

[bricky21]

The way you have your drawing oriented all of the rims odd numbered holes should be for the NDS for a standard build, but since your doing 3:1 half of the NDS rim holes (3 7 11 15 19 23) will be DS spokes which is why I think that the offset rim will not work for 3:1.

Perhaps rruff or one of the other professional wheel builders will see this and chime in with a better explanation.

[rruff]

Yes... you most definitely do not want to do 3:1 on that rim. You'd want a symmetrical center-drilled *stiff* rim for sure. And frankly, I doubt it would work decently with any rim or hub.

Bricky's 12-12 pattern is by far the best choice.

[aerogurl]

I have a couple 7800 front hubs, 32h and 36h, and I would like to lace one to a 24h front rim. Lacing would be radial for simplicity in calculating spoke lengths; can't imagine it will vary even a mm from a 24<>24 radial build.

Should I use the 32 and skip every 4th hole or the 36 and skip every 3rd hole?

Thanks!

[Causidicus]

.

[WMW]

It will look better if you don't lace it radial... and the flanges will last longer as well.

Figuring out the spoke lengths isn't hard if you are decent with geometry.

This might be helpful: http://sheldonbrown.com/rinard/36-24.htm

[aerogurl]

Thanks Ron. If I build the 36h front up 2x on both sides (as pictured on the drive side of the example on Sheldon's page) will the flanges be "out of phase" and under a twisting force when the wheel is tensioned?

The 7800 hub flanges are pretty beefy and "shimano approved" for radial lacing. Aesthetically I think 2x will look nicer though.

[bricky21]

Not trying to speak for rruff, but he helped me understand exactly what you're asking. Yes, it will be out of phase if you were to laced the front wheel as you asked.
There are a couple of good patterns within this thread to do 24 spokes on 36 hole hubs.
viewtopic.php?f=3&t=91823&hilit=lacing+pattern

[WMW]

I'm really glad you chimed in, because you came up with some great patterns there: viewtopic.php?f=3&t=91823&hilit=lacing+pattern&start=30#p791388

Am I correct in thinking that aerogurl could use either pattern for both sides of the front hub?

[aerogurl]

Thanks gentlemen. I was thinking that using the "DS" diagram (from Brickys post linked above) on both sides of a front would result in an out of phase hub flange situation.

Basically, I'm hoping for a symetrical (same pattern on both sides) solution that won't torque the hub flanges.

[WMW]

If I'm seeing things right, you should be able to move that pattern 45 (or 90) degrees and put it on the other flange.

[bricky21]

rruff-I think you're referring to the NDS pattern(3 crows foot and 3 radial)? It won't work for both sides. I tried. The best options for the front hub seemed to be the patterns you had passed along, or something with 18 spokes.