The 1500 spring ended up working good for me. I first tried shaving the inside of the stock rollers from the 6.5 grams to 4.5-5 grams and made the take off and up shift much better and did not loose any top end speed, but it still would not downshift till it had slowed considerably and throttled back and rolled on again,and going around corners did not downshift like I wanted. I went to the middle contra spring (1500 I believe), and back to 6.5 gram rollers and take off, up shift, and downshift was vastly improved over stock. Best part was if I rolled off throttle when slowing for a turn and rolled back on through the turn, it put me right in the power band again. It has been my experience on that one and others that a light roller and weak contra spring that up shifts great, will not down shift as well as a heavier roller and stronger spring combo even though the up shift is similar. IE- Heavier components equals more downshift when throttle and/or speed is reduced.
Also if you get a contra spring from a Super 8 2T, it works great with the stock 6.5 gram rollers in a AG50.
