Wheel building day
February 5, 2023 § Leave a comment
When you are young and have a bit of extra dosh you spring for the aluminum spoke nipples to save rotational weight. They also come in neat anodized colors if that is your thing. I used a lot of these aluminum nipples back in the day, mostly in pursuit of the weight thing although I do seem to recall some purple ones at one point. I also had them installed on my road bike build back in 2000. The only trouble with opting for aluminum nipples over the more standard brass ones is that after more than two decades of service you notice this. A spoke nipple about to break off.
And then you notice that it isn’t just the one that is bad, and that wheel is potentially fixing to explode with minimal warning. (Ok, wheels rarely explode with catastrophic failure all at once. More typically you would lose a spoke or two at a time. But still, this is not good.) I think I had noticed this situation right before I had promised to lend the bike to a person from out of town at the behest of a friend. Luckily I had another front wheel I could quickly substitute but it is obvious that I should not be riding on the wheel in this condition.
Luckily, I’d previously ordered up a new rim and the necessary spokes to match the rear one I replaced due to a dinged rim* which I had been tolerating during the first months of Covid. (It only took me 30 or 40 minute to figure out where I’d stashed the package of spokes.) When I finally had a free afternoon, I was ready to go.
Building bike wheels may seem like it takes advanced skills but it really is not that complicated. If you have the basics of wheel truing down, for keeping your existing wheels up to snuff, you already know most of the fiddly bits of the process. All that is left is first, making sure to get the right parts for the wheel you want to build. This is mostly down to spoke length, spoke crossing pattern and a decision on whether to use an asymmetrical back rim (you should for most multi-gear wheels). One popular book from back in the day is from the late Jobst Brandt, legendary bicycle tech nerd and keyboard warrior in the Usenet rec.bicycles.* forums. A great tutorial from the late Sheldon Brown can be found online, as can tools for calculating the length of spokes you would need for a given hub, rim, spoke count and spoke lacing pattern. It’s pretty simple. Front wheels (rim brake wheels) use the same size spokes. Rear wheels have shorter spokes on the drive side, since the rim is dished over towards the drive side hub flange to account for the gear cluster.
Once you have the parts, you snip out the hub of the old wheel….
And start lacing up the new rim. I never remember what I am doing anymore so I get out another 3-cross wheel for reference. I may once have had a copy of Jobst’s book but I don’t anymore. Using a model wheel helps a LOT to get it right the first time, especially when it comes to the space for the valve. The DT Swiss RR 411 rim that I am using, like the matching (asymmetrical though) rear one I used, comes with its own spoke nipples (“SQUORX”) and washers that have to be used, so there was no option to use the standard brass ones that came with the spokes. The nipples also have some sort of proprietary starred driver head**, a tool I also had to get for the prior build.
The washers are prone to being dropped inside a box section rim. And therefore to require some annoying fiddling to get out again. I dropped two washers and one nipple, and managed to get them out again. 😡🤬
All laced up. This is the hard part. Tensioning and truing is relatively easy after this. Relatively. The most important principle for me is “go slowly and consistently”. As in you tighten each spoke, in order, just a little bit at a time and move around the rim. Pause during the the initial tensioning to verify the true, true it up and go back to tensioning. That’s my method. At first you can count threads on the spokes to keep things even. But once you reach all of them on that last visible spoke, you have to count nipple turns. Again, you are working gradually and consistently around the wheel to gradually tighten all the spokes the same amount. Some people put a piece of tape on a spoke to help them keep track of where they started. I just use the valve hole or, on some rims, the seam that is across from the valve hole.
It is best to use a truing stand for this part. It holds the wheel in place and lets you keep an eye on true and rim centering between the axle nuts. It is possible to build a wheel mounted on the bike and using rim brakes or a taped on pencil to true it. But that is not easy.
In the end, you are trying to achieve identical tension in all spokes (front wheel) or all spokes on a side (rear wheel). Once I reach the stage where the end of the nipples are at the last thread on the spokes, I advance in no more than a single turn of each nipple before moving on to the next one. Rapidly this becomes a half a turn and then a quarter turn.
As you get close to final tension, there is a step to make sure you don’t have spoke windup. You can sometimes take a turn where the nipple stops advancing on the threads and the spoke twists. The tension on the nipple head might hold it in place. So you lay the wheel down horizontally on the axle and gently push down evenly at 9 and 3 o’clock. Then rotate and do the same at the 12 and 6 o’clock positions. Flip the wheel over and repeat. If you hear pinging, you had spoke windup that was relieved by putting lateral tension into the wheel. Either due to the washers under the Sporx nipples or my generous use of anti-seize compound on the threads, this is the first wheel I’ve built that didn’t have any pinging. Put it back on the stand and re-true it. N.b., expect to get some more pinging as you first ride the wheel and put real world tension dynamics into it. You may have to true it up again. [ETA: nope, no pinging on the first ride. Good job me.]
All trued up, and I think tensioned sufficiently. I don’t own a spoke tension measurement device. I just test it by hand and compare to one of my other wheels. No doubt this is a bad idea but you can always tension the wheel again if you went too light. Tire mounted and ready for a test ride. I will once again have a wheelset*, instead of the mismatched wheels I’ve been riding for so long. (No this likely makes no difference that I can feel on the bike.)
*actually the rear rim replacement was on the original Chorus hub that I got with the bike. At some point years ago I thought it was getting dodgy past my maintenance tightening and I just bought a whole new wheel on a Super Record hub…some sort of sale was on. The rim on this latter got dented and this motivated me to use the original Chorus hub. So now I will be back to a matching wheelset. And have another rear to rebuild at some point.
**a Torx, apparently, although in this case the driver is female and the spoke nipple is the male side of the Torx.
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