Hi All, Just brought my new (used with 5000miles on it) CBR600F4i home. MY wife followed me in the car. She aid we were travelling at 65mph most of th eway yet the bike speedo said 70 to 73. I dont believe the sprockets ahve been changed. Has anyone else seen this on their machines?

most of the speedo's are off on the bikes. you can get a speedo healer to fix the problem if it bothers you. but most of us just try to get an idea of how far off we are and then just go with it from there. the speedo seems to be off a little more the faster you are going.

didn't have that problem on my F4i in the UK so I was surprised, particularly as it was so much., nearly 8%

+1 it seems to get worse the faster ya go....

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2007 CBR 600RR Two bros. C/F slip on--Dynojet usb P/C--Custom mapped--Vortex sprocket -1 front+2 rear--DID X-ring chain--hh pads --Pilot power rubber--competition werkes F/E. Oem blue solo seat cowl and no rear bitch pegs!

some factory speedos are off as much as 10%. If it get's worse as the speed increases it's likely the gearing.

I bought my f4i and thought all was stock, and when I went to convert the bike to 520 and -1 +2 I found out that the previous owner had it down 1 in the front anyway...

Going to check the gearing to be sure and do some test with the wife driving the car on cruise control to get at least an idea of the % ir is off. It gets "worse" the faster you go just cos of the math 10% of 10mph (1mph) is a lot less than 10% of 70mph (7mph) so it looks a lot worse at 70 than 10.

I'll bet you are running a 15 up front.

seller swore there were no mods but will check. Does Tire size affacted the speedo accuracy? I have 120/70ZR17 and 180/55ZR17 on. DOn't know if they are standard fitment, maybe not.

the tire width wouldnt affect the speedo but if its not the correct height then yes it will throw off the speedo.

Tire wear will affect it, too, since tear wear changes the height of the tire and the resulting circumference. With a new tire, on most Honda's, you have +5.5% error. An average worn tire is about +6.7% off, while a bald tire gives you around +7.6% off.

Sprockets, of course, will make a huge difference. If you go -1 +2, it will kick it to about +19% error.

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CBR954RR