My mechanical experience comes from years wrenching on Japanese bikes; especially vintage bikes so values may vary a bit but 12 plus VDC at idle and 14.5 at 4K rpm are normal for most any bike. The higher voltage is regulated by your regulator/rectifier and must be this high to keep the battery charged... if the bike runs at 12VDC at speed, there isn't enough positive potential to charge the battery. BTW: I am a professional mechanic BUT don't really know Triumphs well as I have just owned and not really done any serious wrenching so the values Richard gave may be true for a BA but the principle is the same. BTW: If you live upside-down, will voltage values still be the same? Bwhahaha
