05 R6 SS gearing for RA

[spymoto]

The ratio of most sportbikes today is about 3:1 when comparing the rear and front sprocket tooth counts. That would mean you were running what would work out to be apx a +5 gear on the back (if using a stock front gear - original 16/48 gearing came on that bike new). I'm finding that gearing hard to believe for Road America, unless your corner speed was on the slower side, your letting off / braking really early, or your really heavy (or some combo of those)? With a +2 set-up on my bike I will run out of gear at the very end of the front straight, I find it hard to believe you would make it very much past the Start / Finish line with a +5 set-up before running out of gear. Could you confirm that those are actually what is still on the bike from last weekend?

I went out and looked at the bike. It is 15 front and 50 rear. I was running a 190 rear tire if that makes any difference with the added weight of rotating mass.

Well I weigh about 180 and when I went into most corners, I was thinking I could have braked a bit later and had a higher corner speed. That Race Saturday @ RA was my first day on a bike this year and low sided in T-5 during the second warm up, so I was a bit weary of putting it down again. My quick shifter rod broke, so I went back to normal shifting. I'm not that fast, I think my fastest lap time was a 2:38. I didn't hit the rev limiter at all on the main straight or coming into T-5. Maybe my power Commander moved my rev limiter back??? But I sure hope not!

[GSXR RACER MIKE]

I was running a 190 rear tire if that makes any difference.....

There's what I was looking for!

While it's true the original tire size for your bike is a 180, it's made for the original 5.5" wheel width of your 2003 R6. Most likely the 190 width tire you have on there is intended for a 6" wide wheel, if it is then (even though it will fit) the profile of the tire is not as intended by the manufacturer because it's being squeezed together on the sides which makes it taller and narrower. If you were to take a tape measure and measure around the largest circumference of that tire (when mounted and properly inflated) you would find it would be larger in diameter than the original 180/55-17 that's designed to be on that 5.5" width wheel.

Can you use that tire? Sure. But have you tried using the original 180/55-17 tire size? I personally wonder if the distorted profile of the 190 tire MAY have been a factor in your crash? Doing a quick search online I found the 180 vs 190 on a 5.5" width wheel has been a topic in quite a few forums with somewhat of a split in preference as to using the 190 or not. The general consensus seems to be that the tires profile is indeed changed and that more aggressive gearing changes need to be made to compensate for the larger diameter.

Once I saw the tire width the gearing you were using at Road America made sense! 

[spymoto]

hmmmm... Now you've got me worried! The reason I run the 190 is because I use my friends take offs that he only uses for one race and tosses them. I'd rather run the 180's I think because they are 1 pound lighter and thats a lot for rotating mass in my mind. He's been running a 07 GSXR 750 and a 07 R6r... I didn't realize the rims were different widths. Thanks for the good info! Now what to do???  Looks like I may have to spend 3x more money on tires again =( 

Before you ask... personally I can't really tell differences between tires.  180 vs. 190 vs. slicks vs. Dunlop vs. Mich vs. Pirelli vs. (round vs. "V" shape front tires)   As long as they are steady and don't let go in corners I'll like them. I'm not finniky about little tweeks, my riding adapts to the set-up, with no real opinion on the set-up good or bad unless it's really out of line. I'm guessing that's a bad thing!   I've never done back to back tire tests, so I guess it's hard for me to tell the difference between the different types of tires when there is a minimum of 2 week gaps between rides... I guess I can relate it to beer, I like beer and drink what ever is on tap and will not complain because they all taste like beer. But if I had 10 beers lined up in a row and could taste them at once, I'd be able to pick which one tastes best to me and order that when ever possible  =)