after a season on the bike and having the horst link examined by mechanical geniuses, i have come to learn a few things about the jamis design.
use of this bearing for this type of application is not ideal. these tiny bearings are not designed to take such a heavy load. turner might have a thing going with the use of bushings.
monitoring of the rear suspension is required for longevity of the bearings. this design has a flaw in which the load of the rider is on placed on a bolt's thread. the design should have put the load on a solid round shaft rather than a threaded shaft all the way through. the original bolt gets loose every ~5 hours of riding. when that bolt loosens, the thread strips easier and then bearings alone are exposed to the weight of the rider and will require replacement. therefore, it is important to monitor the bolt for loosening.
if you have busted bearings, replacing the bearings alone will cost you frustration. here is why... you need to replace the bolts due to stripped threads, which is the load bearing surface. running the bike with the stripped threads will damage your new bearings in a short period of time. go to a hardware specialist to get a stronger bolt. the stock bolt is made of a weak material, so ask for a material with higher carbon content (harder). after i changed mine, the bearings have not required replacement for last year's entire night riding season. the stock one is a silver color and my replacement has a black anodized finish.
now i have no issues with the rear suspension.