Lightened Flywheel

[Doom Patrol]

A friend and I were talking about lightened flywheels last night and the conversation moved on to other things, as it does. But it got me thinking all the same. What exactly is the effect of a lightened flywheel? I've heard it said that they place less stress on the engine for obvious reasons, but what exactly do they feel like to ride? It's an intriguing idea, but I've always imagined that the die off must be immediate rev wise and that the engine might feel gutless, for want of a better word. I'd welcome any thoughts and observations on this.

[bristolmod]

as I understand it, ,its a diminishing return up through the box.....

Acceleration is better in all gears but less so as you get into 2nd, 3rd and 4th. Also tick over can be "lumpy" as the weight isn't there to smooth out the engine cycle.

There is less weight on the crank which must be beneficial.

Personally I'd like to give it a go but don't know where to get it done

Chris

[Doom Patrol]

Sorry, I was talking specifically about the dinky AF Rayspeed flywheel in particular. But a regular flywheel lightened does sound like a happy medium.

[GP Kevo]

If it is a standard engine you can rest assured that Innocenti came up with the best flywheel weight for acceleration vs cruising. A flywheel's mass provides intertia which can be a boon to the scooter at speed as the spinning mass can help keep the engine running at that speed but a hinderance when accelerating. An AF light flywheel is really best suitable for a tuned engine that is expected to rev out through the gears very quickly. It also makes 1st gear starts prone to stalling if you're not used to riding a Lambretta with such a light weight flywheel and as bristolmod has said, it makes tickover not as smooth. With an AF flywheel you'd need to set the tickover at a faster rpm than with a normal weight flywheel.

It really all depends on your engine, state of tune if any, and your riding expectations.

[sean brady scooters]

this uses the AF light flywheel...
you may notice how low and even the tickover is still,and how tractable it still is when pulling away slowly........
http://www.youtube.com/watch?v=GRC2UfKM ... re=related

[Doom Patrol]

I do like a bit of inertia I have to admit. Having said that the video is very impressive and there doesn't seem to be much wrong with the way that scooter was running. Was it helped by the open mouthed carb allowing it to run smoother do you think?