03-01-13, 12:33 AM
That's a nice neat job you've done there davec, looks like a really well fettled bike. :thumbup
As Limax says, a 10A fuse is marginal. The initial resistance of a cold 60W 12V filament is only about a tenth of an ohm, so the fuse is in a race with the headlight as to which one lights first. The last thing you want as you gas the bike down a country lane and flick to main beam is to be plunged into darkness instead!
A shorter run of thicker cable is good for getting the power to the bulbs but gives the fuse a harder time as the initial current is much higher, the higher resistance of the old cable run limited that current. The fuse is there to protect the cabling rather than the load, I don't know what wire gauge you've used but judging from the photos it looks beefier than the original so a 20A fuse should be regarded as a minimum.
As Limax says, a 10A fuse is marginal. The initial resistance of a cold 60W 12V filament is only about a tenth of an ohm, so the fuse is in a race with the headlight as to which one lights first. The last thing you want as you gas the bike down a country lane and flick to main beam is to be plunged into darkness instead!
A shorter run of thicker cable is good for getting the power to the bulbs but gives the fuse a harder time as the initial current is much higher, the higher resistance of the old cable run limited that current. The fuse is there to protect the cabling rather than the load, I don't know what wire gauge you've used but judging from the photos it looks beefier than the original so a 20A fuse should be regarded as a minimum.