[lincpimp]

Hmm, 7s a123 will spin a casle neu pretty fast, you will need to gear down some to run similar speeds to what you have now. It will also make more torque and possibly work your batteries harder. The flux motor is identical to the castle neu internally. No experience with the tekin, but the magnets tend to come off the early production motors so make sure yours is a later model (I think they have fixed this by now so not a big deal)