Flywheel weight tech

[2-Strokes 4-ever]

The more I think about this, the more my brain hurts. :bang:
Let's say there's a choice of two different 10oz weights to install. One is your typical aftermarket disc type bolt-on weight (solid metal from center mounting hole to outside radius) Or........ a "ring" that tack-welds to near outside perimeter of stock flywheel....both are 10oz. Wouldn't the "ring" type give you more inertia, more "effect?"

 

[Rich Rohrich]

The more I think about this, the more my brain hurts. :bang:
Let's say there's a choice of two different 10oz weights to install. One is your typical aftermarket disc type bolt-on weight (solid metal from center mounting hole to outside radius) Or........ a "ring" that tack-welds to near outside perimeter of stock flywheel....both are 10oz. Wouldn't the "ring" type give you more inertia, more "effect?"

Yes, the moment of inertia ( an object's ability to resist changes in its rotational velocity) would be greater with the ring type. Any time you move the rotating mass away from the point of rotation it requires more torque to speed it up as well as slow it down giving more of a "flywheel" effect.

Where is probably as important as "how much" when it comes to modifying flywheels.


moment of inertia = k*M*R2

M=mass
R=radius (radius is larger with the ring type weight)
k = shape dependent inertial constant (technically the constant would be greater for this design as well)

 

[wileyE]

what Rich said ^

Another option is to replace your alum clutch plates with steel, if they aren't already. At the same time see if the basket has enough room to machine it for 1 more plate set.

 

[2-Strokes 4-ever]

Thank you. The tight, rocky, old enduro type stuff we ride is murder on me and my light flywheeled RM. I have to be SO quick with the clutch when lugging it. I have a 12oz ring type weight a machinest friend made, along with an alum shim for ign cover. Perhaps an extra steel clutch plate is something to consider. I can live with chasing the rear end of the bike around, but am getting really tired of stalling... and I've got the pilot real crisp. Maybe an autoclutch would be a solution.

 

[Rich Rohrich]

Maybe an autoclutch would be a solution.

Installing a Rekluse is a much better solution than a flywheel weight.

 

[2-Strokes 4-ever]

Installing a Rekluse is a much better solution than a flywheel weight.

Expanding on that thought........ What about both? I guess a Rekluse be dialed in to make a flywheel weight not needed at low rpm's? It seems that the extra weight would be a benefit in the faster "rearend hop" stuff too. I've been looking for an excuse for an autoclutch. :nod:

 

[Rich Rohrich]

You're getting into an area where only you as the rider can tell if the combination of the two is an improvement for your application. The Rekluse is worth the money and even on a 60hp engine has proven itself reliable in my experience.

 

[wileyE]

Expanding on that thought........ What about both? I guess a Rekluse be dialed in to make a flywheel weight not needed at low rpm's? It seems that the extra weight would be a benefit in the faster "rearend hop" stuff too. I've been looking for an excuse for an autoclutch. :nod:

The autoclutches are heavier themselves, so you usually don't need both, you could give it a try though? If you go that route I'd suggest getting one that still has the manual clutch lever. There's time when you want to slip the clutch when IT wouldn't.

 

[2-Strokes 4-ever]

Good info. Thanks.