PPIR trackdays

[Kim-n-Dean]

The error percentage isn't linear, it grows exponentially as speed increases due to wind resistance and tire slippage.

166 was the highest speed I ever saw at PMI, it was Brad Hendry.

It's always been explained to me that the error is exponential, but the percentage stays the same. That's how the speedo healers work. You dial in the percentage of error. Again, that's how it is always explained to me.

We did several runs at 100, 120 and 140 and the error was the same, percentage wise. Perhaps the higher speeds do change the error, me haz no clue...

That would be a fun event. Get a bunch of knuckle heads together and shoot everyone with a radar gun. Where to do it would be the problem!

[rforsythe]

Assuming absolute correlation between bike speed and tire speed, the percentage of error should be the same (obviously 10% of 10mph is a lower value than 10% of 150mph). If the tire speed is altered due to slip or other factors, that error percentage will not be constant and whether it moves your readout up or down is entirely dependent on how it's measured and what caused the error.

[Kim-n-Dean]

At the higher speeds you probably are spinning the tire pretty good. I followed Turpin around PPIR and his R6 left a black mark all the way down the straight.

[rybo]

That and as you pitch into the corner you're rolling of the center of the tire (largest diameter) to the edge (smaller diameter) which would raise wheel speed and indicate as a higher speed on the gauge.

[Kim-n-Dean]

That and as you pitch into the corner you're rolling of the center of the tire (largest diameter) to the edge (smaller diameter) which would raise wheel speed and indicate as a higher speed on the gauge.

Yeah, I'm just talkin' 'bout the straights, top speed.

Set up a high speed shoot out, Scotty!!! Know anyone with a runway?!?