I need to replace stock bearings on my 6384 motor (6800 and 6900) to stainless or ceramic, but not sure what and where to by from. There are some german webshops with plenty models in stock, but shipping and fees will be about €40 to my country so are looking for options on Aliexpress or Ebay, which means mainly chinese bearings. I would prefer ceramic which are priced from €3-10 on Ali. The problem is I don’t know the quality and if they are worth buying. I have tried googling the different names found on Ali, but can’t find any info/reviews about chinese ceramic bearings, so if any of you forum members have tried Ali ceramic bearings, it would be nice if you could share experience with them and what brands (links?) to go for.
I had the same problem, although shipping was „only“ €16.9. Got these for my 63100: Edelstahl Dünnringlager SS-6800 >> Bestellen Sie heute!, 3,78 €
They work well and play is OK.
I could not find stainless ones on ali, but I tried these hybrid ones:
US $28.52 8％ Off | 10Pcs S6800-2RS 10x19x5 mm ABEC-7 Stainless Steel hybrid Si3n4 ceramic bearing 6800RS 6800 2RS Without Grease Fast Turning
They work but I prefer the stainless steel ones, they have less play.
Order some spare ones, you need to change them once in while.
I have ordered from Kugel-express before when they shipped with normal Mail, but now they use only DHL €25 which also triggers some VAT fees, so I rather spend the money on some “quality” china bearings instead
Regarding hybrid bearings I saw a video from a cyclist who warned against it because the balls being harder was wearing out the races causing play, so for me I only go full ceramic ZrO2 which should last long time, or stainless and replace once a season or so. The challenge is finding the right quality for the task.