Fire, Unless trinity has changed the spur gear adapter, save your money. There were a few of us that bought them when the XXX-S first came out and were very disappointed. None of the ones that I have seen are round! The gear area is fine but where the belt runs was not. The belt would be loose then bind (oblong) which would stretch it out real quick. We could tighten it up so that it would not skip but it was just too tight to work properly. Luckily my local hobbyshop owner took care of the problem for me.
Cain, I ran the older version one Chameleon last nite on a pretty large track with gearing 23/90 and it made run time plus with a 2000 pack. How tight is your belt, how long ago was the motor trued up? Chameleons seem to be hard on the comm with the laydown brushes and the high timing. We are getting about 3 runs before they need to be trued up. We do run the 3000s but with the new GP3300s coming out I would wait a couple more weeks for them. They are much cheaper for top quality cells so I would think that stick packs would be cheaper too. If all you are racing is mod or spec mod I would think you would enjoy the added run time of the nimh cells and not notice the voltage difference.
Doug