Maybe not normal but certainly a pretty trivial problem. Or is that just because I started my motorised life in the days when a 30000 mile decoke was normal?
I agree with the Monkey, it's probably at least partly due to vibration. When I'm going laning I turn the headlight off to hopefully lengthen its life a bit.
Its not only due to vibrations its more due to high voltage levels !
Bulbs are designed for 12 V operation.
Modern vehicles need high generator voltages to supply all the electrical equipment and charge the battery.
So generator voltages rises from (bulb lifetime saving) 13.2 V up to 14.8 V.
This leads to a drastically reduced bulb lifetime.
Typical example Vauxhall/ Opel Astra before installing a wire with high resistance.
There are several threads confirming the charging balance of our bike.
OK. I can turn it off, which is great. But how do I turn it on again when I'm riding? Or do I have to stop, turn the ignition off, then on again to get lights?