Upgrades usually improve one aspect of a bike, so if you can find a part that improves multiple aspects, its a great benefit. This is what I found after upgrading the rear wheel gyro flywheel in my Duratrax DX450 (or Anderson M5 cross for you guys overseas). The stock flywheel is made of steel and the upgrade is made of aluminum.
Here are some notes I have comparing the stock vs aluminum version:
– stock flywheel without weights = 349 grams
– stock flywheel with weights = 536gr
– weight of flywheel weights = 187gr
– alum. flywheel without weights = 164gr
– alum. flywheel with weights = 351gr
So, with full weights in the flywheel, the aluminum version reduces weight by 185gr or 0.4 lb. That is a HUGE amount of weight to lose on a small 1/5 bike. Before I upgraded I was running the stock flywheel without weights for quicker handling. The aluminum flywheel with weights installed weighs as much as the steel flywheel without weights, yet gives great stability because the most important weight on the flywheel is on the outer ring.
The entire bike was lighter so it accelerated quicker, steering felt more responsive, and the rear shock is more reactive and allows for lighter oil to be used. Another benefit I can see is for those running motard, where you could run the aluminum gyro without the weights installed so there is still gyro stability on the bike but I bet the response would be great.
Take your pick:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXAVVG&P=7 (Note: This is for the street bike DXR500, but it is compatible with the DX450.)