15/40 to 15/45 gearing for a 600 trackbike

[Kitt]

Honest question here...

Is there a significant difference in rotating masses, say between a 14 vs. 15 tooth sprocket or a 45 vs. 42 tooth sprocket? I'm asking from a practical perspective, not a numerical one (I can easily crunch the numbers myself if I wanted to, but I don't want to get into measuring ounces of unsprung weight). Is this difference completely negligible compared to the increase in rotational acceleration of the wheel sprocket?

I would say as far ass the mass of the sprockets, it's essentially not much difference at all... not that any of us could tell.

for instance, comparing a 14/42 with a 15/45 - you may may have a couple extra links w/ 15/45 and the moment will be a touch longer, but i'd say nil. Reason i recommended going down one from stock in front, and up less in the rear, because it would have saved from buying a chain. If doc's doing the chain anyway, then I suppose it's up to him... although it's been suggested that down 1 in front would be an issue.

[Doc]

http://www.gearingcommander.com/

[Jim]

doc, you're an expert racer now. since it's only for track days, just ride the fuggan thing & make adjustments if/when you need to. since you're prob just doing CR, i highly doubt you'll need to be making many gearing adjustments.

[butcher bergs]

All this concern over gearing and it's not even going to be raced?

[Doc]

All this concern over gearing and it's not even going to be raced?

doc, you're an expert racer now. since it's only for track days, just ride the fuggan thing & make adjustments if/when you need to. since you're prob just doing CR, i highly doubt you'll need to be making many gearing adjustments.

True. I might as well go back to stock but since I am laying out the coin for new gearing I figured I might try and pick up the optimum gearing for Loudon.

[keeena]

Doc - My track-only '03 ZX6R originally had 15/48 (change is 0/+8 from stock). This is how i bought it and did my first 5 TDs last year w/ that setup. Didn't like it much, gearing felt way too short overall. This winter I changed it to 15/45.

[Doc]

Doc - My track-only '03 ZX6R originally had 15/48 (change is 0/+8 from stock). This is how i bought it and did my first 5 TDs last year w/ that setup. Didn't like it much, gearing felt way too short overall. This winter I changed it to 15/45.

THANK GOD a useful post!

Maybe I will just stick with 15/45