We have the same problem with the small roller bearings top and bottom of the shower door, I have replaced them twice before by just rining Aquadart and they sent replacements out FOC. Unfortuantely now the company that took over the name refuses to honour any warranty or even supply spares.
I bought some small roller bearings from RS Components and made up adapter spigots on my lathe, they fit OK and roll but they are still not ideal as the bearings are stainless steel with square shoulders and the shower channel is aluminium and requires ideally rounded edge bearings, the dorr opens and closes now without falling out of the aperture but it takes a LOT of effort as there is too much friction with SS in an Alu runner.
If anyone knows a supplier of plastic coated bearing, please let us know!
I cannot beleive these bearings were only made exlusively for Aquadart, there must be other manufacturers out there that use them?
David
June 2011