hey a friend of mine told me to go put my idea up on a forum, i am currently making this TRUE fixed 2 speed with a 2 speed front crank. what i am using is a modified tensioner and a clutch type mechanism. i am using a thumb push shift to move the front derailer, and for my "clutch" i am usng an old style road bike brake lever, i am putting a parking break style lock (idea came form atv parking break) to keep tension in chain when i am on the lower gear. im sure you cant imagine what i am doin till u see pics, but i am currently in the middle of gathering up parts and starting to put my hand drawn designs into effect. when i get some pics together ill post them.