I thought I would add this to the Touring forum as the bike I was dealing with was my touring bike and I would think most touring bikers are more likely to have spoke problems and when they do they are a bigger deal.
My bike a Windsor Tourist has been noted for coming with cheep spokes and or poor installation from the supplier. I was aware of that when I bought the used Windsor and asked the owner if he had any spoke issues and he said no but also never rode with a load and or any great distance. So I took a chance and did ok for a while. I had two spokes break last year (back wheel cassette side) and after the second one I took the time to check them all and found a few less tight and tried to correct the problem. This year I broke 4 more and said enough and started looking into a super wheel 48 spokes that lead to tandem bike parts that lead to wider spacing that lead to custom hubs that lead to $$$$$. and I started reading up on how all the 36 spoke touring bikes that were doing fine and thought ok lets lace what I have up with quality spokes done by hand by a pro and see what happens. and that’s what I did.
I have access to a materials testing lab and I thought I wonder how much stronger the new spokes are so I tested some and what I found was interesting and I thought I would share. (photos below)
What I found was a little surprising at first. The old spokes broke at about 730 pounds average, while the new quality spokes broke at a average of 755 pounds in the straight section. so they are a little stronger but not as much as I thought I might find. what I did find is the machine has the ability to know when a sample first starts to yield and then stops increasing the load and hold at a constant load. This is to measure different modes of fatigue etc. The spokes that came with the bike would hit failure force and then quickly break maybe 5 seconds. the new "better" spokes would start to deform in failure and then would maintain strength for several minutes. I'm not a metallurgist so I don’t know what exactly the property is that causes this but the tester said that’s a indicator of the difference between just hardness strength and strength thru a combination of hardness and alloys. I could actually feel the difference when bending the spokes by hand slightly the good spokes felt less strong or more bendy. So there is some component to the material.
I also took a couple photos of the head of the spoke as about half of them broke there. the better spokes have a much deeper chamfer to the head, the cheep ones look more like a nail head, flat on the bottom. Also the photos might not show this but there are way less tool marks in the radius area under the head, (stress risers).
The quality spoke is the one with the hallmark stamped on the head. I took my bike shops word on this spoke as being good quality. Anyone familiar with this spoke fill me in please.
Lastly is the quality of the build and only time will tell me the answer to that. Hand laced vs machine built will be a big factor I think. My guy did say to ride a couple hundred miles and bring it back it to be trued as spokes will seat sometimes at first. so I plan on doing that.
Here are a few photos:
