Personally, when riding a motocross track, I find myself favoring the 250 four-strokes. They are easier to ride, confidence inspiring and they are lighter but my main reason for favoritism is that the power is so much easier to control. When riding a 450, it's easier to get out of control and the power makes it hard to stay smooth in the turns. However, it is still nice to have that extra power for those moments of hesitation when committing to a new jump. I looked at a heavy flywheel as a solution.The $149.95 Trail Tech + 17 ounce flywheel fits the bill. I installed one on a '09 CRF450 and was quite happy with the results. As you may know the CRF is very crisp off the bottom-a little too crisp for me. But after I installed the heavy flywheel the power was quite a bit smoother down low. It took away that snap that tries to rip the bar from your hands and replaced it with some manageable torque and improved traction. This made entering and exiting corners a lot more controllable, especially in less than stellar conditions (over-watered, off-camber turns). It even helped out on the rougher tracks, making the bike easier to hold onto. The rear end seemed to hook up a lot better, and I didn't notice any loss of overall power. All this added up to more laps on the track and less fatigue by the end of the day. Another plus was now being able to take this bike to some trails. The heavier flywheel made the bike less prone to stalling at low speeds, and with the added torque, I was able to chug up just about anything. Maybe not as much as a true enduro bike, but it did make this motocross bike at least enjoyable on the trails.Installation is simple. Just pop off the sidecover, remove the stock flywheel with a flywheel puller, replace the stock bolt holding the cam-chain tensioner with the provided screw and install the new flywheel. It's that easy. Make sure to swap out that bolt as the increased size of this flywheel means tolerances are getting tight and the added clearance is needed. The flywheel on my bike adds 17 ounces over stock, but Trail Tech also makes a flywheel that is 11 ounces over stock if you don't want to make as drastic of a change as I made.A flywheel mod is a great option if you are looking to smooth out the power delivery on your monster of a machine, add some torque feel and reduce stalling without affecting the top-end. Plus, it is easy to install and as reliable as stock.