ign1te

Hi.

I have found that manufacturers and retailers are somewhat vague in their description of various items. Information regarding nipple thread length is an example. Spoke head diameter is another. I am located in the EU and order most of my things from Bike24. I therefore decided to order a bunch of spokes/nipples. I then proceeded to measure various dimensions and tabulate my findings.

The information is primarily aimed at people interested in wheelbuilding. The information is found in the attached pdf.

100bikes

Awesome.

tomtomtom123

I'm not an expert but from what I learned with building a couple pairs of wheels is that the Sapim spokes that I received can vary up to +/-1mm in length, and the threads could vary up to 2 threads of difference for the same spoke length or by almost 1mm. I would assume the same would be true with other brands. Final spoke length and amount of threads would depend on the machine and tooling that the spoke was made on, and some sellers/builders trim and roll their own threads with a spoke threading tool when they don't have the required spoke lengths in stock. So I don't think you can make an accurate generalization that you can apply to figure out the exact spoke/thread lengths that you will receive based on brands.

I'm not sure why spoke head diameter is important since load isn't being applied to the full surface area of the head, but the Sapim spokes that I received in different years had different head diameters, I assume because of variations on different batches made at different times.

Regarding thread lengths in the nipples, it's been generally known that Sapim Polyax 12 and 14mm nipples have the same thread lengths starting from the top of the head, and the 16mm is theoretically 2mm longer, although your investigation reports it as 1.5mm. It's also generally known that DT Swiss nipple threads increase in length between the 12, 14, 16mm nipple lengths. I assumed it was 2mm difference in thread length between each increase in nipple length, but your investigation reports this as 1mm of increase.

I'm not sure why nipple head diameter is important since load is also not being applied to the full surface area of the head. The diameter of the nipple shaft is more important to determine whether it will fit through the holes in the rim.

When I built my newest pair of wheels, I wanted the ends of the spokes to stop at the bottom of the slot of the nipple head, which I measured to be around 1.5mm below the top surface of the Sapim Polyax nipple. However they ended up being around +/-1mm of the top surface of the head. There were 2 spokes that were even higher, around +2mm above the nipple head, so the spoke threads bottomed out on those nipple threads. I found that the Sapim spokes generally bottomed out when the ends were on average +1mm above the top of the head of the 12 and 14mm Sapim Polyax nipples. But that would also depend on the +/-1mm variation in spoke lengths and 1mm variation in thread lengths. However I think turning the nipple another 2 threads further past the bottoming-out isn't that big of a deal, as the brass threads in the nipple will simply give way to the stainless steel spoke.

Another issue that will affect where the spoke ends in the nipple is the variation in the location of the spoke holes in the hub flange. The holes in some Novatec hubs that I received were not centered to the axle, but varied by up to 0.5mm, which means that spokes on one side would end up threaded into the nipple up to 1mm further than spokes on the other side, if the spokes were identical in length.

mpetry912 

the variation in length can be accounted for by sloppiness in the spoke cutting technique. I have a Phil machine and my spokes (with careful attention) are very consistent. However I've occaisionally gotten others with variance of + / - a mm or so.

Very good info, ignite, thank you !

Mark Petry
Bainbridge Island, WA USA

ign1te

Thank you for your nice post!

The machinery used to make spokes is not perfect, and there will be small variations from item to item. Process-inherent variations of 1 mm quite seem too large to me, and I would certainly expect more of Sapim and DT. This should not be confused by the fact that some spokes model will have different spoke lengths by design. If you look at the thread length comparison in the document, the Sapim Leader 2,34 mm has a significantly longer threaded section. In my mind this is intended and not due to random variation in the machining process. This is supported by the fact that all 2,34 spokes I ordered share the same, larger thread length. At the same time, I do not mean to imply that your observations regarding large variations are false. Hopefully those were from an odd batch .

For enormous retailers such as bike24, which is now part of the CRC group, the order volumes must be enormous. They most likely order spokes by the tonne, literally. It would make no sense for such companies to cut their own thread. Therefore I am fairly certain they were cut at the factory by the manufacturer. Smaller establishment can certainly cut their own thread, giving rise to unpredictable variations as you say.

Take a look at the spoke holes of coaster hubs, and you will most likely find that they are enormous. A larger spoke head provides a better seating of the spoke into the hub hole. Of the 2,34 mm spokes I have measured, I have found that their heads are consistently larger than their 2 mm counter parts. I personally would not build a coaster brake wheel using anything else than the larger-head variety spoke.

The nipple head diameter was included to give an idea of the physical size of the nipple. If you ever come across a 14 mm Sapim round head, you will probably be as surprised as I was regarding their enormity.

I too struggle with some spokes not being of correct size in the finished wheel, even if the majority of them are. This aspect is exacerbated by the fact that I only have access to spokes in 2 mm increments . I typically end up with having to included a mix of nominal sizes for a wheel to be built according to my satisfaction. I should also add that I use the flush-with-slot configuration as reference when determining the ERD.

ign1te

I am deeply envious of your Phil machine. Do you own one personally or do you simply have access to one?

Dan Burkhart 

I have never used a Phil Wood machine, but my Morizumi is very consistent cutting the length. This may be partly because the cutting and threading are two separate operations, whereas the Phil machine combines them.

kingston 

My favorite part of the report: