Tyre driven dynamos
Tyre driven dynamos don't work well.
The generator unit (technically an alternator) is very robust and lasts forever, but the wiring is the problem. Most use the frame as an earth, and this always has problems getting a good contact. The pulley also slips on the tyre, and bulbs blow if you go too fast. There's also lots of drag, which slows you down. The lights go out when you stop, a disadvantage in traffic.
They did provide a better light than the old filament bulb battery lights, which is why they were used.
We have fitted one in the past seven years, and that was to a 1935 bike. They are still listed in some wholesale catalogues so if you want one you can have one... but please fit it yourself. There are better alternatives.
In the early 1980s tread driven dynamos were sold. These fitted below the chainstays, behind the bottom bracket. This solved the slipping and tyre wear problems, but exposed the unit to as much spray as possible in the rain or on a wet road. They wore out in weeks in Scottish weather.
The generator unit (technically an alternator) is very robust and lasts forever, but the wiring is the problem. Most use the frame as an earth, and this always has problems getting a good contact. The pulley also slips on the tyre, and bulbs blow if you go too fast. There's also lots of drag, which slows you down. The lights go out when you stop, a disadvantage in traffic.
They did provide a better light than the old filament bulb battery lights, which is why they were used.
We have fitted one in the past seven years, and that was to a 1935 bike. They are still listed in some wholesale catalogues so if you want one you can have one... but please fit it yourself. There are better alternatives.
In the early 1980s tread driven dynamos were sold. These fitted below the chainstays, behind the bottom bracket. This solved the slipping and tyre wear problems, but exposed the unit to as much spray as possible in the rain or on a wet road. They wore out in weeks in Scottish weather.
