Top Speed

According to the seedo my bike tops just about 155. But i think the specs only show 143 or so for a top speed. Is the speedo off? The only mod i have is a erion slip on.

 

The speedo is off somewhere between 5% and 10%

 

All speedos in motorcycles and cars are off.
One of the "worst" or optimistic was the Kawazaki ZZR1100 from the 90s.
That one showed over 300km/h(187mph) but the real speed was around 275km/h(171mph)

 

What model is your bike?

 

I have a 98 VFR 800.
Would a power commander increase top speed.
I don't open it up all the time. once really just to see.

 

That sounds about right, observed once while sitting on a sustained indicated 240kph (150mph) with the GPS reading a steady 222kph (138mph)

 

Anytime I pass a radar sign, it shows me about 5mph slower than my speedo reads, and all I got is a Staintune slip on. No sprockets. So I figure it reads faster, which is ok with me. Less tickets for 70 in a 55.

 

I run with GPS most of the time and have always been surprised with how optimistic the speedo is. Both on the VFR and the SV the speed indicates 5 mph faster than the GPS. I believe the GPS is correct. Another thing I have wondered about is the mileage (distance) seems to right on both of them. Now, how'd they do that?

 

They do it on purpose.

I have a speedo healer to recalibrate my speedometer and odometer because I have changed gearing. It is set right now so that my speedo is accurate, but my mileage reads 8% lower than actual.

 

I don't know exactly about my VFR- I expect it's electronic, but on older bikes, the odometer runs off a cable so it is direct drive, while the speedo is on a spring that is moved by a magnet.

 

I have noticed also that the speedometer is 5mph higher than the speed my gps says. Not sure of that is true at 100+ mph speeds since I generally don't take the GPS on a track. Also I usually don't look down too much at those speeds. I am too busy texting...