Hypothetically- M900 mods.

[Darkness]

Physics dictates that rotational inertia impedes acceleration, which is why a lighter flywheel is considered to be a performance mod.

Less rotating mass = more acceleration, if all else is equal.

I was hoping someone had done the maths on costs and comparative effects of losing 1Kg from the flywheel, rear sprocket, and back wheel & tyre?

Weight reduction of the sprocket, wheel and tyre also has the benefit of reducing unsprung weight making the suspension’s job easier too.

[utopia]

Originally Posted by Darkness

Physics dictates that rotational inertia impedes acceleration, which is why a lighter flywheel is considered to be a performance mod.

Less rotating mass = more acceleration, if all else is equal.

Yes, one of the effects which I wasn't really expecting from fitting my carbon wheels was the improvement in acceleration of the bike.
It stands to reason I guess but I hadn't expected the effect to be large enough to notice.
In fact, I've ended up dropping another tooth off the rear sprocket as a result of the improved straight line performance.

[Luddite]

Originally Posted by Darkness

I was hoping someone had done the maths on costs and comparative effects of losing 1Kg from the flywheel, rear sprocket, and back wheel & tyre?

There's a very simplified calculation ('force = mass x acceleration') in the Ducati Up North article on lightened flywheels http://www.ducati-upnorth.com/tech/flywheel.php which also touches on the benefits of lighter road wheels.

Here's an extract:

"When you remove weight from the flywheel (and to a lesser degree, from the clutch) the effect on the engine’s ability to more quickly spin-up is indistinguishable from increasing your engine’s torque (and consequently horsepower) output.

But only in neutral. In any other gear, there’s little benefit at all.

Obviously, your bike’s ability to accelerate faster through the gears is enhanced by reducing the overall weight of the bike as well as the inertia of rotating components. The crankshaft, pistons and connecting rods, transmission gears, drive chain and sprockets, wheels and tires, clutch and flywheel are all candidates.

However, the overall weight of the bike and rider completely overwhelms any reduction of rotational inertia produced by a lighter flywheel. A kilogram lighter flywheel on a 300 kilogram bike-plus-rider will accelerate only 0.3% faster. F=ma.

Of course every 0.3% helps a racebike. When you reduce weight you’ll get faster acceleration, and faster lap times - IF - you can modulate your wheel spin driving out of corners. Factory racebikes make so much power, for example, that transmitting the power to the road effectively becomes the limiting factor - so heavier flywheels actually become a benefit. Fear the high-side."

[Darkness]

Thanks Luddite. Yes, I’ve read that post previously but it doesn’t really answer my question.
The 0.3% improvement mentioned is solely due to the reduction in mass, a three hundredth of the weight of bike and rider. It completely ignores rotational effects.

https://en.m.wikipedia.org/wiki/Newton's_laws_of_motion

It should be possible for me to get my remaining brain cells to quantify the change, I was just hoping someone had already done it!