Removed per members request.
Hi Fitness,
There is information out there about the relationship between size and wear/dislocation but I can't remember the source, Google should be able to help. If it helps, my BHR is 48mm, nearly 9 years old, and working well - running 25/30 miles a week, racing from 5k to half marathons and getting out in the mountains.
My ceramic THR is much smaller, and working just as well...
Dont worry about 50mm!
Pete