Wire sizes - FYI

banner001 · Post by **banner001** » Sat Mar 08, 2014 12:22 pm

As im doing my re-wire i thought it might be usefull for other people to know what wires are in our bikes.

The wires here are from my 1989 FZR 1000 EXUP-R, but should serve as a general guide.

The wires from the battery to starter relay, starter relay to starter motor, and from the frame to the -ve terminal are "large", these are composed of 84 strands of 0.45mm copper wire, cross-sectional area of 13.36mm2 and a total thickness of 7.2mm, current carying ability ~90A.

The "live" wires from the ignition, the red wire coming from the alternator and the wires going to the main fuse are "medium", these are composed of 26 strands of 0.3mm copper, cross-sectional area of 1.84mm2 and a total thickness of 3.2mm, current carying ability ~24A.

All the other wires are "small", these are composed of 20 strands of 0.17mm copper, cross-sectional area of 0.45mm2 and a total thickness of 2mm, current carying ability ~10A.

Vagabond · Post by **Vagabond** » Sat Mar 08, 2014 12:28 pm

Thanks,

That was a question I needed answered as I need to rewire an '78 CB750 SOHC I'm rebuilding

banner001 · Post by **banner001** » Sat Mar 08, 2014 12:40 pm

meant to add, the current capacity, is a CONSTANT current carrying capacity, the wires can accept slightly higher current for very small amount of times, thats why the wires are slightly lower in current than the fuses, if a high current is applied the fuse will blow first as its thinner and will heat up a lot faster.