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06 R6 speedo said 180 at redline, anybody have a correction

2K views 10 replies 7 participants last post by  gridopezzo 
#1 ·
All you guys can call bs if you want but I swear on my life that I did it on the way home today. I have a completely stock 06 R6, and I mean stock. It has 4100 miles on it and it still has the original tires airfilter and pipe. The only thing I have done is change the oil with mobil 1 full synthetic. I pulled through the gears and bumped it into sixth and just wanted to see what it could do know that its all broke in and has the good oil in it. The speedometer indicated a speed of 180 and the tach was right on or only about a hundred or two away from 17,500. I know the speedo isnt going to be completly accurate at that speed but does anybody know with the stock gear ratio what the bike is supposed to do at redline in 6th gear. Now, it is time for a new back tire, it is wore down pretty good in the middle so I know that will make some difference but I wouldnt think that it woud be more than a few mph. Thanks.
 
#2 ·
Firstly, you weren't at 17,500 rpm. But you probably know that.

Secondly, I was told that the speedo error was ~ 7.5%. This would make your "180mph" run approximately 166mph, which is within reason. Going down hill, with the wind, with a worn rear tire, etc, can increase the error.
 
#3 ·
hey pinkslip, you're a smart feller! (& no, this is not sarcasm)
 
#4 ·
Pinkslip said:
Going down hill, with the wind, with a worn rear tire, etc, can increase the error.
A worn tire has a smaller diameter, so the ratio of wheel revolutions to engine revolutions changes, altering the speedo accuracy. That makes sense. How does going down hill change the error? It might let you go faster, but it would also spin the tire faster, which would cause the speedo to keep pace, albeit with the same error rate.

Right?
 
#5 ·
Going down hill allows your bike to go faster with less effort. Depending on the degree of the hill, it might shave 100rpm off your engine's strain(?)
 
#6 ·
Cheapmods said:
hey pinkslip, you're a smart feller! (& no, this is not sarcasm)
;) Thanks.

That's why we're here- to share our experiences, wisdom, etc.
 
#7 ·
yea, i had mine on the dyno, at redline the speedo said 186, but the dyno said 166. something tells me that pinkslip stole my numbers... :sing
 
#10 ·
Well I dont like to brag or anyting but after 55mph I turn into a super hero!!! So I can only die if I am going slower than 55. The faster I go the more invincible I become. Cars can acually pass through my body as long as I am going over a hundred!!! Its a pretty impressive site!!! I'll try and get a vid.
 
#11 ·
Pinkslip said:
Going down hill allows your bike to go faster with less effort. Depending on the degree of the hill, it might shave 100rpm off your engine's strain(?)
No, that wouldn't be possible. The engine crank is directly connected to the wheel through a series of gears. When the wheel goes faster, the engine goes faster. Going downhill the engine will crank at the same rate for a given speed. The difference is it takes less fuel to maintain that rate. For a given gear ratio, the only thing that allows the engine/wheel spin ratio to change is the clutch, so if you slipped the clutch, it might work.

Because the engine/wheel ratio stays the same, the speedo error percentage is also the same.
 
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