Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Andrews 21 cams rock

If you have a big Harley bagger like mine with an otherwise stock engine, these cams are your ticket. The 21 grind has the lowest RPM punch of any cam Andrews makes. The "N" series allows you to use a new style cam plate and oil pump on an older (99-05) twin cam motor, and you end up getting away from those problematic spring loaded chain tensioners. I have had these cams in about a year and a half now and all I have to say about them is good.