Tbf you can replace the bearings in a shimano BB
Gently prise off the top hat and seal covering the bearings then tap out the bearings from behind
When you order the new bearings, you’ll need some 6805 bearings – I just got the cheapest off eBay at 3.50 inc postage but if they work ok (give em 6-10 months and ill know for sure) I’d consider ceramics for more cash (20 quid should be enough)
Press em in, cover both ends in grease to help seal em better but you’ll need to shave / sand the 1mm lip off the top hat or get new ones from superstar. Reason being is the original bearings have an ID of 6mm. 6805 have an ID of 7mm. The lip fits in this gap and helps seal the original bearing
Seems to have worked so far, after a month of riding. We’ll see what happens in the future tho