I can agree with previous contributors regarding the strength of the fork tubes. I set out on a long VMCC run to Stranraer in 2007. At the start , the forks were working perfectly. At the end of the run they were down, and no amount of pumping would bring them back up. After trying new seals etc , etc, all to no avail, I discovered that the fork tubes were very slightly bent , just below the lower yoke. I can vaguely remember hitting some big potholes on the run, and my theory, now backed up by others is that the fork tubes bent at this time.
After a fruitless search for replacements, I fitted internal coil springs. They work well, but damping is poor and I lose any oil quickly. Some work to be done here. I now have a choice of longer or shorter wheelbase, depending on which way I fit the tubes! The bend is so slight as to be unnoticable, but I am very careful over potholes now.