Theres a few good freewheels on the market, The main three i would suggest are White industries eno, Tensile or Try-all . Try-all Have 108.9 engagements, This means that it will pick up quicker, But i have seen a few Try-alls, Clunk and Bollocks up. Tensile and eno have 72 Engagement points, But ive never seen anyone have any problems with either the eno or Tensile. Personally id go with the eno even though its more expensive than the tensile and Try-all you can get more spares for them incase they go wrong, So you wont have to fork out for a new Freewheel.