Heres a funny thing, in the 12 years or so Ive had my Jackal I never really thought the back brake was very strong, a real good stomp would hardly lock the real wheel.
I've been literally off the bike for a few months following an accident, in recovery. I put another disk on the front, and new braided lines and a new master cylinder (original for 1 disk only) and now have a pretty strong front brake. I discovered the rear line was slightly crimped, in fact ALERT TO JACKAL OWNERS, the rear brake line is cable tied to the swing arm so that its in the exact place where the end of the 'foot' of the main stand will whack it each time you roll off the stand, eventually crimping it. So I put a new braided steel line on and new pads, bled up in a treat with a power bleeder, BUT still weak as piss as we Aussies say! Good pedal feel but no real strong retardation. I don't think the callipers are rebuildable are they?