October 13, 2009 19 Comments
[Note: this is #6 in a series of 20 tips to be published during 2009.]
For those of you that don't know the fastest way to build a rear wheel, here is how. This method is standard practice for many but still undiscovered by most. Building from right to left leverages the inconvenient truth of rear wheels to speed up the process. In fact, this method makes rears faster and easier to tension than fronts.
Step 1, begin by lacing your wheel in the normal fashion. Make sure each nipple is loose but tightened down the same distance as its same side neighbors. Step 2, now tighten your drive (right) side nipples evenly until they become snug. Continue until this side becomes tight, about 2/3 of finished tension. Make sure left side spokes are still loose.
Whoa, you may say, "the rim is now centered over the right hub flange and does not run true." Yes, but no worry, this is exactly what you want. The rim will wobble all over the place since there's no triangulation yet working. Open your truing stand indicators so the wheel can be rotated. Step 3, improve roundness (radial runout) by tightening and loosening drive side nipples ONLY.
This roundness session is the easiest ever because you can entirely ignore lateral runout. Just tighten and loosen nipples until the rim is perfectly round (not true). Use bold adjustments, like 1/2 turns, so the job is quick. Once the rim is perfectly round, we can move on.
In step 4, tighten non-drive spokes to pull the rim away from the cassette, towards the hub centerline. Completely ignore your drive side spokes. As you evenly tighten the non-drive nipples, use them to make the rim true. Such truing, using only one side and ignoring roundness, is lightening fast. The trick is getting the rim to center (use a dish tool to measure) AT THE SAME TIME as the drive side tensions reach perfection. Success depends on how tight you made the drive side in Step 2. Practice with a particular combination (rim, hub, spoke length) to make this part easy. Eventually, it can be super fast.
The advantages are two-fold. First, the process is quicker because roundess is perfected while ignoring side-to-side: half the number of spokes to adjust and much simpler, 2-D reasoning. Then, side-to-side is finished without attention to roundness, delivering the same speed benefit. The second advantage is that drive side nipples become tight without you having to turn them. Tightening a nipple to full tension is work, fighting thread and nipple-to-rim friction. This strategy allows you to tighten non-drive nipples to pull the drive side tight, and the non-drive nipples are twice as easy to turn.
Recognize the potential and give it a try. If you practice a few times, you'll never go back. I wish we could devise a similar shortcut for front wheels or symmetrically dished rears (like some fixies). Rear wheels are less strong structures than fronts due to their asymmetry. But that doesn't mean they should take longer to build. Quite the contrary!
A side note: since wood rims are so flexible, this method doesn't work so well. I still use a front-style of building for my wood rears. How about you?
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