Flywheel effect- fuel economy and rideability

**racefactory** · 11th September 2011, 09:38

Hey guys,

I'm curious to know about flywheel weight and it's effect. Keen to hear of anyone's experiences of tinkering with flywheels.

Using my dirt bike for my everyday commuter as a supermotard and as can be expected it's got too much punch for leisurely coasting in traffic sometimes or when navigating a wet roundabout. It's very apparent that it can rev to the moon and back in a a mere flash compared to say a road sport bike. Even though it can rip your arms off, I can also tell that it slows down on hills a lot more than less powerful bikes.

I'm interested to know roughly how much weight I should add. Would 12oz be enough for a noticeable change? I just want to put the heavier flywheel on for road riding/commuting and then rip it off for track/dirt.

Also, getting more theoretical here; what would be the effect on fuel economy? To me it seems obvious that a heavier flywheel will yield greater efficiency where most of the time is spent at steady speed/cruise, for example a typical passenger car. On the other hand more energy would need to be spent when accelerating through the rev range, correct?

**racefactory** · 11th September 2011, 15:03

Speaking of which, does anyone have a flywheel puller that they could kindly let me use? Cheers.

**F5 Dave** · 12th September 2011, 17:43

A motion pro puller will be cheap as & you should really have one in your tool box, do an internet search or Torpedo 7 etc should stock.

You don't mention your bike? 12oz does good things on dirtbikes with light flywheels so they don't stall as easily & hook up in the mud better. My GG300 was greatly improved, but my old GG200 didn't need one as the flywheel was heavy enough std.

There will be no effect on economy. They don't change the power output in any measurable way.