Bearings do not have enough lube from the factory, so they can run dry after a while & chew out. Pop the blue shields off with a small screwdriver & pack some extra bearing grease into them - I just use normal wheel bearing grease.
Then they are fine & last a long time - I've had mine for proably around 20 gallons in total, I've re-greased them a couple of times.
True track itself is bulletproof, you will never look back after fitting it.