It's my first year really pulling cranks and I'm noticing after a few trips my new cranks are worn the heck out. Looks like the front treble rubs spots on the bellies pretty good. I been pulling 2.0 -2.2 mph range. They are rubbing past the paint. My black cranks look really rough and I'm not catching many slimers. Is this normal or can I change something to enhance the life of the crank?