In 1972, I was at a friends house. He had just gotten his new (to him) sportster and he was showing it to me. He fired it up in his driveway facing the garage door (which was closed). He pulled in the clutch, reved up the motor, and the bike took a leap jambing the front wheel into the garage door. Bent the fork tubes pretty bad. Turned out, the clutch cable broke when he was at pretty high RPM's.I think he was lucky the garage door was there to stop him. I've never busted either a clutch or throttle cable, but then I'm kind of **** about maintenance and I keep them lubed and inspected.

 

In all the years I've been riding, and all the miles I've put on Harley's, I've only had one clutch cable break, and I've never had a throttle or return cable break.

Clutch cable on my 1981 Shovelhead (shown below) went out at about 20,000 miles, but I think it must have been defective from the 'get go'.

I usually give the cables a shot of Dry Slide every 10,000 or so miles, and I check their adjustment whenever I happen to think about it.

Cables should last for a long time if you lube them and make sure there is no binding.