I've been using Daytona Hotgrips for years now, never had a problem with them...
http://www.amazon.co.uk/Daytona-hot-grip...B0052DSKZM
The only slight drawback is that they don't maintain a constant temperature - you put them on "start" until they're well hot (they can get almost too hot to hold, even through gloves) then put them on "Run". They slowly cool down so that after about twenty minutes or so you have to put them on "Start" again. But they have thin bullet connects which means they thread through small holes easy enough, and just seem to be very reliable.
Combined with handlebar muffs over the winter (look crap, but on a 100K divvy 900 for work and back, who cares?) I had nice warm hands every day.
But I've put a pair of the Oxford Lites on the Fazer, and by comparison, they're crap. Even on full blast they don't get anywhere near as warm as the Daytonas.
http://www.amazon.co.uk/Daytona-hot-grip...B0052DSKZM
The only slight drawback is that they don't maintain a constant temperature - you put them on "start" until they're well hot (they can get almost too hot to hold, even through gloves) then put them on "Run". They slowly cool down so that after about twenty minutes or so you have to put them on "Start" again. But they have thin bullet connects which means they thread through small holes easy enough, and just seem to be very reliable.
Combined with handlebar muffs over the winter (look crap, but on a 100K divvy 900 for work and back, who cares?) I had nice warm hands every day.
But I've put a pair of the Oxford Lites on the Fazer, and by comparison, they're crap. Even on full blast they don't get anywhere near as warm as the Daytonas.