Solcar said:
I find it a bit unfortunate that spokes break nowadays. The reason is the metal that they are made of isn't very good for the application.
The vacuum processed stainless steels used in good quality spokes these days is better than ever, and has gotten noticeably better during the twenty-something years I have been working on bikes.
I was just watching some more of the video of Justin riding across Canada using less than $10 of electricity. When 5 spokes on his rear wheel broke he went to a local bike shop and got a new wheel. Not much later, he was met with new "clink" sounds as the new wheel began popping spokes.
The electric assist on Justin's bike was from a front hub motor, so that wasn't a factor in the rear wheel spoke problems.
His rear-heavy weight bias and extra weight of batteries and personal items presented a major challenge for any wheel, let alone a stock robot-built wheel that would be ready to buy at a bike shop. Such wheels can be substantially improved by careful stress relief and additional tension, but they still are what they are-- regular wheels for regular bikes.
I'd be great if a factory opened up a spoke making plant in the USA and they could get it right, with the right metal that resists fatigue. I've never had a spoke break on any of my American-made bikes over the past 40 years.
DT Swiss and Wheelsmith both make spokes in the USA. DT, Sapim (from Belgium), and Wheelsmith all make much better spokes than were available at any price in the bad old days.
I have noticed in my work experience that cruddy old American bikes often do go decades without spoke breakage, even with spokes so weak that they break when you attempt to tighten them. There are a number of factors at work here. Fat, low pressure tires help reduce the forces on wheels. Soft, lumpy, flexible steel rims on old American bikes reduce stresses on spokes because they simply can't be tensioned to normal levels. Most such bikes don't even have
that much spoke tension. The typical (for American clunkers) zinc-plated plain steel spokes could be pretty strong-- or not-- but the corrosion that forms at the threads serves as a natural threadlocker (for better and for worse). The result is wheels that are very heavy, aren't very strong, and can't be kept true enough to be compatible with modern rim brakes, but which don't break spokes much. When overworked, they collapse into a potato-chip shape before the spokes get strained enough to break.
If you build a wheel that weighs the same as an old clunker's steel wheel, but with a good double-walled aluminum rim, quality stainless steel spokes, and appropriate build techniques, that wheel won't break spokes either. But it will stay straight and reliably carry quite a bit more load than the clunker's wheel, and it will accept modern high-pressure tires too.
Chalo
