Lightening Flywheel

[IcutMetl]

I understand the pros and cons of a lighter flywheel. I have a fair amount of bottom end for still having stock gearing, so I'm not afraid to lose a touch and possibly have to fan the clutch a bit more.

What I'm asking is WHERE the material is removed from and how much is taken off when our flywheels are lightened. I got my lathe up and running, and even though I don't have much tooling yet, setting up to turn a little material off my 'wheel would be a very easy task.

Thanks!

[Kirt13]

I don't know if it's a good idea to do it yourself.
When it's done by someone like Ricky Stator, it's balanced during the process. If you don't get it perfectly balanced you could cause some damage.

[IcutMetl]

I can definitely understand the importance of balancing and centrifugal forces at high rpm's. However, if chucked properly in a lathe, and indicated with a tenths/micron test indicator along the bore and then face, it should run concentric with the bore and perpindicular to the face, making it pretty damn close, wouldn't you think?

[Honda 250r 001]

hell remember the genius that did it with a air grinder? lol you will be fine. You remove the metal on both sides of the pick up tab. NOT very much. I may be able to dig up a pic later if needed.

[thedeatons]

Yes, if you are cutting grooves in the flywheel, then it is easy to make them symmetrical. If you are adding lightening HOLES, that is different, and it must be balanced.

I have not seen too many 250R flywheels as of yet, buut I have seen a LOT of Cannondale flywheels. they were balanced from the factory, and have divets drilled into them at certain locations along the flywheels edge, in order to balance them.

I wonder how well the original 250R flywheels were balanced, considering I haven't noticed any balancing holes or weights on them.

I am running a CR250 flywheel now, and did not notice any balancing indicators on it either.....

My cannondale crankshafts, counterbalancers, and flywheels were balanced as a system by an outside source. In stock form I have dynamic balancing sheets that show 350+ pounds of rotational force out of balance, then when balanced it was down to 13 pounds. That was on ONE side of the crank, the other side was different, but it balanced to 13 pounds. The piston weight was accounted for too, to ensure everything was in balance. After that was done the engine was the SMOOTHEST 4 stroke I have ever ridden. No vibrations anywhere.

I would imagine we would need to balance our cranks, counterbalancers, and flywheels as a system too, for perfection.

James

[zedicus00]

we cut our own flywheels on my buddies lathe. he sends his off to be balanced. i dont. niether of us have had any problems after running them long term. my engines are set up high RPM. he takes off a little bit of weight. i cut mine down so much you would think i am mad. neither of us have any extra vibration.

the 2 sides of the story. a heavier flywheel makes the engine spin up more slowly making it more manageable. also it spins down more slowly making it harder to stall.

BUT

a lighter flywheel spins up and down more freely. freeing up more power. giving you more torque down low and more over all power through out the band. the reason it SEEMS easier to stall is that you are not use to it and the new quickness of the engine. also i like that it is easier to engine break.

to me the lighter the flywheel the better, it allows you to more precisely control the ENGINE instead of having to use other devices to help minimize the effects of having to controll the engine. (breaks for when its spinning to fast and clutch for when its not spinning enough.)

counter to what most people say, a lighter flywheel will cause you to clutch LESS because the engine will be able to ppull itself up into power easier then when its fighting the weight of the flywheel.

hope all that made sense.

(NOTE: factory balanced flywheels are still not balanced worth a crap. the more weight you take off the more unbalanced mass you are getting rid of. why balance a chunk of rotatating mass when you can just get rid of it)

[Honda 250r 001]

hey i have prolly asked this a million times, but where are you from in kansas?