Originally Posted by
Kontact
You have built how many wheels? I have built hundreds. The people I have worked with have built hundreds, and the people they learned from have built hundreds or thousands of wheels. All of those people use the same basic set of techniques on all thoroughly modern equipment - not steel hubs. All of us agree on these basic principles, as will any wheelbuilder you care to find. And all of us have seen the kind of elbow failures being discussed on equally modern equipment, and have SOLVED those issues with the techniques discussed. Because machine built wheels commonly have a poor spoke to flange contact, and we have seen that many, many times.
There aren't any "thin flanges" and spoke head washers in modern wheels. All of these dimensions were worked out for alloy hubs decades ago.
There's a few problems here. Firstly (and I'll address this again later) your argument seems to be purely a claim to authority, which isn't an argument but a fallacy. Million flies can't be wrong, pile of... You get the idea.
From what I'm understanding from your post, at some point someone of your old expert professionals mistook correlation for causation without considering the actual cause for elbow breaks. If said person was loud enough or had enough clout, the mistake was then elevated to be a part of cycling lore. Ie. it's a myth perpetrated by people who believe their mentors explicitly (you really shouldn't do that. Question everything).
If the spokes keep on breaking at the elbows, that doesn't mean not insufficient mythical processes were performed for the elbows. It means the elbow is somehow special compared to the rest of the spoke and if a spoke breaks, it'll break at the elbow. The elbow is bent whereas the rest of the spoke isn't. It is is a stress riser. Steel in tension tends to break at stress risers.
If we employ Occam's razor and consider the simplest possible reason why spokes break at the elbow, it's because of the stress riser thing. Not because of spoke path.
That being said, there are other stress risers on spokes. Breaks may also happen at those places. But the elbow is a good assumption for breakage, if a spoke is to break.
It doesn't surprise me that there's a lot of this mythical stuff in wheelbuilding. There was a person who once wrote about compression of spokes. Regardless of what he meant, it was extremely badly communicated and those ripples cause confusion even today.
I, as a representative of the professional wheel building industry, am trying to relay to amateurs how this stuff works and why. I am extending the courtesy of sharing those things the best I can in the face of a lot of objections that are fun to talk about, but are basically the theories of people with little to no real experience or education.
Actual professionals should have white papers, studies, schematics, technical drawings, material charts, manufacturer documents etc. to use as evidence instead of claims to authority to surpass any and every objection. The technical professionals I work with typically never make a claim if they don't have something concrete to back it up.
So this situation is analogous to going to your doctor and arguing about the power of crystals to cure cancer. I don't care what you think you've learned building a handful of wheels, or by reading a metal chart. The basic facts remain the same, and you are wrong. Any pro builder that says that spoke elbow seating is unnecessary would be a fraud - but basically such a professional doesn't exist. Everybody paid to build wheels professionally does it and teaches it because it works.
I've actually been a PRO mechanic one time. I don't flaunt it because it counts for nothing. As to the rest, my doctor wife would be very amused. The medical profession is heavily evidence based for a reason. Crystals have been studied. There are papers showing they don't work. But the medical field doesn't as a collective believe that an increase in ice cream consumption raises the risk of drowning even though there is correlation between the two.
Or you can take the word of the guy who has broken tons of elbows not setting them, and is therefore convinced elbows are delicate and every wheel needs 2.3mm elbows. Even though we know good wheels don't break elbows. Even though being the "go to" guy at a coop is like being the most handsome carnival worker.
There are things in Cyccocommutes methods I don't agree with but this isn't one of them. He does actually set the elbows. But the reason he does it is because it speeds up the build process and makes the wheel less failure prone after it goes out the door to someone who doesn't know how to adjust wheels. I don't do it because I can take my time building and I can adjust them after I've ridden them a while (I don't actually need to though).
But aside from all of the above, if the elbow is such a risk position, shouldn't we build all wheels with straight pull hubs and spokes? No elbow, no problem right? Straight pull spokes should make a practically indestructable wheel. But we know that straight pull spokes do break. What is up with that...