8541Hawk

Had my spare flywheel turned down the std. .5" off the OD
$75 plus shipping (usps $15 in the US)

or if you're in the bay area, you can come by and pick it up and I'll even install it for you if you need.

7moore7

Oooo... pm'ing now...

8541Hawk

PM replied.....

8541Hawk

Sold...... in 6 mins flat.....lol

saige

holy jesus,that might be the fastest on here,was there ever any faster lol

7moore7

Well, at least the lightened flywheels works!

When it's 112 degrees in Phoenix, afternoons are for laundry and forum sniping

smokinjoe73

So whats the deal on the flywheel? Quicker reving? Does it enhance performance or percieved performance?

autoteach

It lengthens your...you know...it's awesome

8541Hawk

The engine will accelerate & decelerate quicker and while there is no gain in HP the energy that was used to accelerate the mass of the heavier flywheel is now used to accelerate the rear tire.

So yes it does enhance performance.

Revelation

Best "value-for-money" modification I ever did!!
Feels sooooo much faster. Aspecially in combination with 15-41 sprockets.

On my black one I am running -10%
On the one I am building, I am going for -15%

jeephawk

You had a half inch machined off the o.d.!
Sounds like alot. Wouldnt that throw the balance off?
Gotta be a typo.

8541Hawk

Yes.....
No.....
No.....

Big Shepp

Essentially RWH figures are somewhere around 15% lower than the crank horsepower. This is because the engine has to centrifugally accelerate all the moving parts in the drivetrain. By lowering the mass of these parts, you decrease the amount of power the drivetrain pulls from your engine and thus increase your RWH without increasing your crank horsepower.

jeephawk

crazy.
so whats the trade off? less torque.

8541Hawk

How could removing mass from the flywheel cause the engine to produce lees torque?

IMHO the VTR as way too much mass in the flywheel as a safety feature to keep hamfisted riders from flipping it over backwards in 1st. Yes mine will flip over on its back with no problem.....

What you end up with is a engine that produces the same HP & torque but rev's like an RC51.

Tweety

If you really need to find a downside to the mod, there is a small one... Like hawk said, the VTR's large flywheel is a "safety feature", and if you ligthen it, the bike becomes a bit unruly if your not careful with the throttle...

7moore7

From what I've read, aside from the twitchy throttle, and depending on how you ride, you may lose some mpg, especially at cruising (as there is less inertia keeping the components moving).

mboe794

I took half an inch off the radius of mine. Or, in other words, a full INCH off the diameter. The shop said they ckecked it afterward, and it needed no adustment for balance.

Removing material from the outer edge should actually make balance less of an issue.

Tweety

It CAN affect balance, but the more you remove, the lower the resulting imbalance will be...

It's simple really, X% of the total weight is the imbalance, and when the total goes down, so does the weight of the imbalance, even if the % stays the same... Plus, the resulting radius that acts like a fulcrum for the weigth becomes less, so all in all, even with an inherent imbalance, the % will drop as well... It's physics...

Tweety

Well, yes and no... It's not going to affect the mileage either way really based on the flywheel... But since it's not smoothing out what you do, if you are inefficient with the throttle, it becomes much more apparent...

Ie if you are ultra smooth and efficient, the lower flywheel weight can actually help you conserve fuel... Unlikely, but it's a possibility...

nothing

is it hard to remove the flywheel I've never done it.

RWhisen

I would think that it would have a less consistent idle as well.

Tweety

As far as I can tell, the idle remains the same, equally consistent as before...

But then, my bike is dead on in terms of carb syncronization and other factors, so I can easily drop my idle below spec and it will remain stable... If the bike is setup a bit less precise, and prone to stalling or other misbehaviour at idle, then yeah, a lighter flywheel will make that worse...

So my interpretation would be the same as with fuel consumption... It doesn't change the characteristics, it just shows the flaws based on other things more clearly...

That's the basic flaw of modifying your engine... To get more performance out of it, you tighten the specs... And that more or less forces you to do that across the board, tweaking just about every detail a small amount...