The 11:11 Bearings don't need any maintenance, they get better the longer you have them. They have Steel shields that keeps dirt an dust out. Try some for

Portland Wheel Company Eleven 11 Skateboard Bearings in stock now at Tactics boardshop! Fast, free shipping. No sales tax. Authenticity and lowest price

We tested various bearings over the course of a year to develop the new 11:11 bearings. These bearings don't require any maintenance and will only get faster

SBFD206-20, 1-1/4, 4-7/16, 3-35/64, 3-5/16, 15/32, 15/32, 53/64, 1-11/32, 1.1811 SBFD203-11, 11/16, 3-3/16, 2-31/64, 2-21/64, 21/64, 9/32, 19/32, 61/64