This year I put new axle bearings in my sons kid kart as well as my own chassis. In the past I’ve noticed that new axle bearings can be tight and have extra resistance, but typically loosen up after a few sessions on track. My new bearings behaved exactly like this.
My sons 25mm bearings in his kid kart don’t seem to be breaking in even after 5+ sessions on track. The bearings have been lubed with tri-flow for each run and I’ve used brake cleaner and air to blast out the bearings and then re-lube. This helped a bit but they still have noticeably more resistance than the old bearings to the point I’m considering putting the old bearings back in.
The bearings are standard axle bearings, no ceramic or polished/treatment on them. I’ve also verified the axle is installed appropriately, not bent, and not binding.
Is there something else I can do to help loosen the new bearings? Or since the forces are so much less in the kid kart are they just going to take much longer to free up? Could there be something wrong with them?