How much is the XX's speedo off at high speed? 5-6%? I have dropped 1 tooth on front and was racing a hopped up GSXR 1100. He got me in the 1/4 :oops: but I passed him doing an indicated 190 mph :grin: , and it acted like it could go a little more but I let off. So is my speedo giving me about a 11% higher speed than I was actually going? Was I actually going about 170?

I did a high speed run and saw 191 indicated on stock sprockets and read 178 on GPS after I stopped. Also the bike had more but I ran out of pucker power so rolled off. :shock:

Demon, I read 205+ with 1 tooth down in the front and I believe it came out to be ~15% off.

Most BlackBird speedometers (stock gearing) read about 8% fast. (The odometer reads closer, mine checks off about 3%) When you change the front sprocket, you add in another 6%, for a total of 14% error.

According to my GPS, an indicated 90mph on speedo is @ 83mph on the GPS.

Steve

My speed-o read an indicated 812 MPH but the GPS read an actual of 55....I don't have the balls to push my limits so I rolled off the throttle ever so lightly and slowly. :razz:

15% off with a 1 tooth drop in the front don't sound bad. I guess I was doing about 160. Anyone GPS a 1 tooth down bird for top end? I would guess the top speed isn't that much slower than stock gearing being as the reduced gearing puts the bike in more of the peak powerband at high speed. 175 mph is probably topped out for a geared down bird.