This spring I built myself a new set of wheels for my H1 and decided to use stainless steel spokes. Lots of times I've heard that stainless steel spokes are sensitive to fatigue, and because of this I ended up being very careful not to over tighten the spokes. Naturally I was baffled when the spokes started to break. First one, then a week later another three on a 60 miles trip. I was convinced that the reason they broke was that the neck of the outer spokes was to long which caused some unnatural bending of the outer spokes. Buchanan's was not convinced that his was the problem but agreed that the neck could be shorter, so they gave me 20 new outer spokes free of charge.
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In retrospect I have done some research, including actually reading the yellow note that comes with the spokes, and the conclusion is clear;
Those spokes would not have broken if they were tightened properly.
Here is a scan of the yellow note that comes with the spokes:
And even more interesting; You won't be able to over tighten these spokes according to Buchanan's reply to one of my e-mails:
Quote:
I would recommend 50 “lbs of torque for the rear wheel. It is important to put a light weight lube oil between the nipple head and the dimple pocket of the rim. Without it you lose a lot of linear pull to friction. You cannot over tighten this wheel with the 9ga spoke thread. The limitation will be in the nipple flats of the .250 nipples. Make sure your wrench fits well. As a point of reference I would say you would have 50”lbs of torque with 8lbs of pressure on your thumb against a 7” long spoke wrench.
The main point is to get the internal load of the wheel structure to be greater than the external loads placed on the wheel. Whether the outer spoke have 1/16th “ clearance from the flange or not is not critical from a structural consideration. If you think about it all the inner spokes have at least that much clearance from the hub on any conventionally flanged hub.
To solve your immediate troubles I will be happy to give you the 20 outer spokes with the slightly shorter bend and also a few extra nipples at no charge. I will pay the freight. I would recommend you replace all the inner spoke at this time making sure to achieve 50” lbs on the build.
Thank You,
Robert B.
The main point is to get the internal load of the wheel structure to be greater than the external loads placed on the wheel. Whether the outer spoke have 1/16th “ clearance from the flange or not is not critical from a structural consideration. If you think about it all the inner spokes have at least that much clearance from the hub on any conventionally flanged hub.
To solve your immediate troubles I will be happy to give you the 20 outer spokes with the slightly shorter bend and also a few extra nipples at no charge. I will pay the freight. I would recommend you replace all the inner spoke at this time making sure to achieve 50” lbs on the build.
Thank You,
Robert B.
So, there you have it, learning something new every day.
Maybe someday I will learn to read the instructions before I start.
Regards
PK