uchi

imregearing soon and i was on a site and they offer a drilled and a solid piece, assuming both are just as strong would there be any advantage to the drilled one if it were a bit lighter? i know that a lighter rim will make a difference but in something like this is it worth the extra money?

PUSHrod

Only to have something to talk about during a visit to the burger barn bike bash.

Tweety

Are you serious? It's probably the same weight difference when you clean and lube the chain...

The rear sprocket might actually be measurable difference in a solid vs drilled/contoured... And it is possible you can measure the difference in a stock brake disk vs a contoured...

It's the same with 520 conversion... Yeah it's lighter... And yeah you can probably measure it on a dyno... Just outside the error margin if you are lucky... Do all of the above and you might consistantly repeat the measurement without having to worry about the error margin...

Or eat a few less hamburgers for a month and you will have increased performance twice as much...

When you use lighter wheels it's a difference of 5+ pounds... Not 5 ounches...

uchi

wouldnt have asked if i wasnt serious, i asked because on something like that i assumed it may have the same affect as lightening the crank or flywheel.

zmaniv

Im not trying to insult your intelegence but the crank and flywheel spin much faster than the front sprocket.

Freeing up unreciprocating mass on the crank and flywheel will allow the engine to spin up faster.

the overall weight of the front sprocket is like a 1/4 pound where the flywheel is like 10.

I have a spare one and I am going to try one modified then the stock size to see which one I like better.

Tweety

Ok... Sorry bout the ribbing then...

The difference in a drilled or not front sprocket makes so little weight difference it's like I said probably possible to measure it... But If you can feel it with your "*** dyno" you *** needs to be recalibrated...

Lightening the flywheel is a whole different scale on weight... Same as for wheels...

Look at it this way... Take some 10 decent thick washers in your hand, or some 10 nuts... That's the weight you "save" with a drilled sprocket... That's not really going to affect much...

uchi

haha not insulted and no worries about the ribbing, im too new to stick it back to you guys just yet but once we all become friends everyone of you is fair game

do you have your flywheel done?

uchi

i think you have that backwards. the front sprocket spins faster than the crank and flywheel

but i understand what youre saying with the flywheel and crank. im toying with the idea of getting the flywheel done, i know in my car when i had it done it cost me a bit of low end but the motor spun up that much faster and felt stronger up high. somehting like this would nicely combat the urge to wheelie from the regear i have in mind.

Tweety

I have a spare flywheel milled and ready for install... I'll do my normal teardown routine in some 1-2 months, where here in Sweden the roads ice over so I can't go outside and play...

zmaniv

Tweety put some sheet metal screws into an old set of tires and have some fun.

Tweety

Heh... For fun in the winter I have a sled... And a GSXR 750 with studded tires for ice racing on a nearby lake...

Playing on the streets just isn't any fun when it's icy...

uchi

wicked, do you have any info on the flywheel? i wanna yank mine and do it aswell i think over the winter, one more mod to surprise people with in the summer time

Tweety

Took .5" of the diameter and since it was balanced to begin with I had it re-balanced... That's somewhat conservative as people have done .5" of the radious, but too much and the engine will be too peaky and snatchy... Gonna try this and see what it does...

Do a search and you'll find 2-3 discussions on the topic... All with relevant information...

uchi

right on thanks ill have to take a look next time i get some more free time, my evening it just about to start so ill check into it tomorrow

shayne

As well as weight, the size of the components will be a factor as well I think. Wheels are a good example of this. Manufacturers try to keep as much weightaway from the rim as possible, where the gyroscopic effect is worse. Closer to the hub is less of a problem.

The countershaft sprocket is so small and so little weight, I see no advantage at all.

As for the effect light weight components have on the reciprocating assembly, as Tweety says it may not be much on a dyno, but throttle response is very important when riding the bike, and less weight makes this better.