I had lots of problems like this. Mine was caused by the length of inner going into the back of a speedo. It was 2mm too long, so when I tightened the knurled nut, it locked the inner into the back of the speedo, it turned, but with a lot of resistence. It took three cables at £26 each before I worked it out for number 4. Best of luck.
Jim
Hi Jim,
I'd read about this and had checked it - and of course I have now snapped 10 cables so unlikely they were all made incorrectly ( and I tried two different outer lengths so they won't all have been made on the same jig I guess).
Part of my challenge is the intermittent nature of the fault - I rode 800 miles to and from the French Rally faultlessly and then the first 100 or so on the IoM before it snapped (again) then 2 in quick succession.
I have now stripped the angle drive at the speedo end and found four or five small shards of bright shiny metal in the grease. They shouldn't have been there and now the thing has been cleaned with stopquick till it sparkles and then assembled with fresh grease. JJ Cables have suggested I run the druve up in the vice with a drill for a while to test it - and are supplying me a short section of cable to do that with. I will give that a go. Then maybe I will run the cable assembly on the bike with the angle drive connected but not to the speedo and see how that goes.
Very very frustrating - especially as I recorded the entire Parade Lap with my high definition head camerac mounted to my helmet and the speedo registers zero, wella ctually that is not such a bad idea I guess as the lap was meant to be at 60mph!!
Cheers
Keep everyone posted as to progress.