How do you know its not the cable?
If all the hardware of the clutch is stock, then either you're a wimp, or its the cable. (No offense, just trying to make a point.)
It could be the routing, but if that is stock. Cables can be bad internally, they can be microscopically frayed causing lots of friction under load, but virtually undetectable when not under load.
Sometimes people think the cable is good because it hasn't seen much action, but that could be the worst. The lube will have drained out, and little balls of rusty corrosion breakoff the cable once put back in use, and if bad enough you can never get it clean or lubed back to snuff again.
Don't rule it out, especially if as said the clutch springs are stock and the lifter isn't damaged in some way. Only way you can really rule it out is to replace it.
Also the pivot hole in the lever can be worn, sometimes they have a little brass bushing that goes.