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Posts tagged ‘spokes’

DIY: Weaving a Strong e-Bike Wheel

The wheel on the micro-carpenter table

The failing wheel on the micro-carpenter table.

Like any other emerging technology, electric bicycles have their rough edges to iron out. With hub motors, one of the issues that might occur is wheel strength. Namely, my rear wheel came with the standard spokes you find on most bicycles, only shorter because the motor makes the hub wide. In my case, the motor weighs about 6-7kg, so the problem with using such spokes is that the motor gives them a heavy beating and they often snap. Although the motor represents a very small part of total weight (6kg, vs. 110kg bicycle + driver), this weight is directly hung on the spokes and there is very little amortisation. If you’ve ever chopped wood with an axe and the axe gets stuck in the log you’re chopping, you know that if you turn the axe upside down, the sheer mass of the log splits the log when the axe lands. That is (more or less) the effect the electric motor has on the spokes. (more…)