My 05 F model eats speedo cables every 6 to 8 K miles. Stock one lasted to 6.8 the next I put on a year or so later lasted to 14.5. Just courius, I dont really "need" the speedo, I've rode it enough with a GPS to know how fast I'm going in any given gear with the tach, just a pain to keep up with the fuel economy but on a bright side I have a low miles GS  .

Are the replacements OEM or pattern?...... How are they failing?

I would say not normal.  does it break it at the same place each time?  the little wire speedo cable holder at the bottom may need to be adjusted, it could be putting too much pressure at the cable at that location, causing them to break there

The replacement was OEM, I haven't removed it yet but the last one broke just above where it goes into the front axel.

And, how is it breaking?  I conjecture that when you do a wheelie, the forks extend too far for the cable, and thus, it breaks.  Test by putting the bike on the centerstand, and pressing down on the grabrail to lift the front wheel off the ground, and moving the handlbars from steering stop to steering stop to see where the cable is binding, or getting caught up at.

The front wheel has come off the ground once, on accident. I don't thrash this bike, it very rarely sees 9.5k rpm. I just might give up on it this time and just keep a bike with 14.8K miles on it for a while.