Let me just say that this $9 sprocket upgrade works great! I'm 250 lbs and wow, what an improvement! I use to have issues pulling hills and maintaining speeds on an incline but not no more. It actually pulls in 4th gear now! The gearing feels much better. It doesn't feel like it's over revving or any where near the redline either. I'd imagine that may happen to the lighter riders because it would go through the gears quicker. I recommend this upgrade for anyone 200+lbs. Here's the part # if anyone's interested JTF249 14