I've had the Whirly cranks on my Necro for 8 months and have been put through hell and they have performed brilliantly. Well worth the money.
"Start and end at a brewery, and a very cool snow and Ice urban/cross country, lake ride in between with flasks ful of Krakin... YAH MON!!!!" - Vibrato
"Every one of you should ride a bike and be yourself. I really and truly believe that bikes make the world better, and that anyone who spends some time getting used to life on the saddle will find that it makes their life and the world that their life is locked to, better; in almost every way." -Gern Blanston, Surly Bikes