Well, number 10 wire can safely carry 30 amps, number 12 carries 20 amps. So it isn't the terminal ends that may be a problem, it could be the wires themselves. These wires will carry significantly more for short time periods tho. As far as what the batteries "hold", a cycle battery like we use can probably punch out 200 amps or so. A car battery can do 500-600 amps. But it really doesn't matter how many amps the battery can deliver. What matters is how amps does the starting motor ask for when cranking.
I believe that our bikes use from 60-70 amps during normal cranking, a locked rotor would draw more, but that doesn't often happen. It also really doesn't matter what the charging system is putting out. That isn't enough to be a problem with either the wire or the clips. A CX's max output is 170 watts, which at 12 volts is slightly less than 15 amps. A GL produces 250 watts, a little over 20 amps.
Bottom line is that it should be OK. Just don't crank too long, if the bike's battery is completely dead and you are only using the jumper to power the cranking.
