I know what you mean about dust. When my RCs come into some of the corners, on the backyard track, the tires grab handfuls of dirt/dust and is thrown onto the hubs/spindles/diff outdrive bearings. Over the past 10 years, I've gone through changes to my RC's maintenance schedules. As the number of RCs grew, so did the cost of upkeep. Tossing crunchy bearings... I was going through, somewhere near, 144 bearings a year. I needed to change something. Going from cleaning the bearings and shocks on my RCs once a month (approx. 25 runs on each RC), I'm currently at the point where I do shock/bearing cleanings every 12 runs. Is it worth it? For me, it is. I have not tracked my bearing cost in the past year, but I know it's less than $24 for all my RCs combined.
It's the price I pay for enjoying radio controlled off-road toys outside my backdoor.
Do you mean, by cleaning your bearings less often they are lasting longer? or did you just start driving in a cleaner environment?
I protect my motor bearings as best as possible. i place a piece of duct tape over the circular bearing hole on the back end of the motor can, and on the shaft end i cut a very thin, flat and round piece of tire foam(the cheap black foam, not proline lol) with a small slit cut in the middle, and slide it over my motor shaft and pinch-mount it betwen the motor and motor mount. smear some grease on the exposed surface of the foam, this will act as a dust filter. now the only way dust can get in is thru the sensor port and around the seams of the motor can.
Personally, i dont like to touch any of my bearings for fear of pushing the caked-on dust into them; i dont service them until they fail. In the motor bearings' case, i replace them at the first sign of imperfection/increased motor temps. Ive been running my et48 with fasteddy rubber sealed ceramics for 6 months in very dusty contitions with no failures yet, including motor.
My dad has been cleaning all of his bearings every 1-2 months tho, no failures there either. So idk.
I used to spray all my bearings with wd-40 after every run, mostly because i ran in wet conditions and i wanted to try to repel any water before storage. but i concluded that i was flushing too much dirt to the inside of the bearings- either that or i was failing to flush the water out, and 1/4 of the bearings would fail within 1 month. I stopped running in wet conditions, and ive had no bearings fail in 6 months.
What ive learned in the past 2 years about bearing life (throughout the car) is that rotating mass is everything for bearing life. never oversize any part of your car, especially the tires. the drivetrain and the bearings in which it rides was only designed for what the manufacturer intended. oversizing your tire diameter or width by even 1/2" will half the life of all of your bearings. similar consequences should be expected when installing bigger/aluminum diffs and metal spur gear... rotating mass increases.
I did all of my "learning" on a piece of junk rtr traxxas. these teknos are superior in every way.