the problem is this, O.G. wheels are 24" and use custom length spokes, making them costly.
using available parts we will build new alloy 26" wheels for the" one inch axle upgrade" and to retrofit onto O.G. axles
buy these parts
2 rims part number 14-290 from Mulero
2 boxes of spokes, stainless 10 gauge 245mm part number 58-290 from Mulero
tires and tubes and rim strips
4 W1B hubs from surplus center
2 single split lock collars from surplus center

Step 1: Drill the Rims to Fit the Spokes

you must drill the rims for the spokes, the head of the spoke will not pass through so break out these bits
top to bottom
large bit is 3/8
next is 1/4 inch
smallest is a .173 also called a number 17, it is a bit larger than a 11/64 which will work in a pinch
the tool on the bottom is a burr remover, get one from any plumbing place

Step 2: Drill the Largest Hole First

work carefully, see inside the hole next to the valve stem? the bit kissed the aluminum of the inner wall when it broke through, try to keep this to a minimum. this problem is why we drill the 3/8 hole first, the next bit will clean up the work.

Step 3: Drill the Inner Wall Next

see? the inner wall is all pretty again, the hole on the right is yet to be drilled. finish both rims this way.

Step 4: Now Use the Deburring Tool

this cleans up the hole so the spoke heads fit like this. burrs will also cut the innertube so be diligent.

Step 5: Drill the Spoke Holes to .173

use the .173 or #17 drill on the hub to drill out the spoke holes.
if you must use the 11/64 drill just wiggle it around a bit to make the hole loose.
make sure the holes have no burrs. it may be nice to get out the 3/8 bit again and kiss the holes with it to bevel them slightly, relieves stress on the spoke heads.
you need to do this or its near impossible to get the spokes in.
if you are building replacement wheels for 3/4 axles you are almost done, just lace up the 26" rim in a two cross pattern, remember not to block the valve stem hole.
if you are building 1 inch axle wheels like the one pictured you will need to continue reading

Step 6: Adapt and Overcome

this is a bicycle wheel hub and a surplus center W1B weld in hub meant for making gears fit axles, I've already cut out the old 3/4 sized one, it was held in with a tack weld from the backside.
you need two W1B's per wheel.
clean up the inside of the bike hub, see that seamline? grind it down.

Step 7: Hub Fitment

yeah, it sticks out a little. be sure to remove the set screws, we are not using them for the welded side. slide it onto an axle

Step 8: Use the Axle to Align the Hubs

slide one hub on the axle then the bike hub and then another hub. sliding them tightly together. check to see that the flanges spin straight, twisting the hub around the axle and tapping and adjusting the bike hub so you don't get an inherently wobbly wheel. tack the W1B hub to the bike hub in four spots , rechecking you work as you go. give it one final spin on the axle to be sure you don't need to tweak the flanges.

Step 9: Weld the Hub From the Inside

remove the assembly and set aside the loose W1B hub. now from the inside weld a good inch on two sides. stay away from the keyway to avoid damaging it. clean up all the weld splatter and you are ready to lace up the rim to your new hub, same 2 cross lacing.

Step 10: Final Assembly

when you go to assemble the complete wheel onto the axle just place a W1B on the axle and slide it up against the bearing, lock it down with the set screws.

Step 11:

then slide the wheel on with the welded side out and put in the 1/4 inch key. The key must measure 1 3/4 long so trim where needed.

Step 12:

Finally put the split collar on, tap it home with a mallet and tighten well, it holds the rim in place. all done! time for a beer.

be sure to send in the rims every year for a tension and trueing. loose and out of true wheels will quickly break. tight wheels spread the load evenly and prevent taco shaped wheels.