Postby Duck! » Thu Dec 14, 2017 11:21 pm
The hardest part about lacing a wheel is working out where to start. On a rear wheel, work the drive-side first, on a disc-braked front, do the disc side first.
First, locate any logos on the hubs, they will give a reference point for aligning with the valve hole. If the hubs are unmarked, start anywhere..... They can also be a clue for whether the hub is designed for 2-cross or 3-cross lacing (for 28-hole you can go either way, but for disc brake I'd err toward 3-cross if the hubs allow).
Working with 3-cross in mind.... any hub logos should sit between two flange lobes. Start at the second lobe to the left of the logo, and feed a spoke from the left side of that lobe (the hub drilling will determine if it's the inboard or outboard hole, thread in from the large-bore side), and attach to the rim at the hole immediately to the left of the valve hole. For your second spoke, Skip two lobes to the right of your start point, and through the third, thread a spoke from the right side up to the second hole to the right of the valve hole. You have your lacing reference spokes in place.
Fo 2-cross, only skip one lobe at this stage, otherwise the process is the same. If the hub is optimised for 2-cross, the logo will align closely with a lobe on each side.
From your reference spokes, thread from each lobe up to each fourth hole around the rim; after your primary spoke, go to the next hub lobe to the right, and to the fourth hole around from that spoke, or second hole past the second spoke (around the rim, spokes alternate from left side and right side, and on each side, leading and trailing spokes, hence going to every fourth hole). Work around and fill in the gaps to this pattern, interlacing at the outermost cross; those spokes that seat in the inboard hole of each lobe will stay under the next spoke (remembering that the lobe itself holds the first cross), then lace outside the final crossing spoke. Be consistent with how far you screw each nipple on, and be careful not to go too far; screw each nipple down to where the tip of the nipple aligns with the bottom of the thread. Once that side of the wheel is completed, flip over and do the other side.
You'll notice here (if you haven't already) that the lobes are not perfectly aligned with each other. From your second spoke of the first side, which you'll now find is two hole to the left of the valve hole, trace down to the hub, and find the pairing lobe that is offset just a little bit to the right. Thread a spoke up and into that hole immediately left of the valve hole. From there the rest of the lacing is exactly the same as the first side.
Once the lacing is complete, the key to building the wheel is small, equal steps to gradually build tension, not big handfuls in one hit. Start by puling the rear drive side and front disc side up to tension first, as they're the higher-tension sides of the wheelset, then pull back with the lower-tension side.
I had a thought, but it got run over as it crossed my mind.