Stock f4i's run out of gear at about 170 but you would have to weigh about 75 lbs to get their. I got mine to about 155 on stock gears, but I think the speedo is about 5 mph high to.
I wouldnt go any higher than 64 because it gets to choppy and you wont be able to ride on the highway with any more than that.

 

The higher you go the more your true speed is off.

 

no a 180,its a vortex though ,maybe ze of the whole sprocket varies between diff.brandsthe si

 

a 58 tooth is great for lot and streets or 1dn 8/9 up.

 

LMFAO!!!!!!!!!!!!

 

i was talking about stock

 

last year i ran a 70 tooth..its great for no hb stuff because the engine brake is insane..but its way too twitchy..i went to a 56 this year and its so much more fun i already feel better than last year one day of riding after 4 months off

 

my geared f41 does about 210....






























thats what the speedo says...

 

your speedo should still say 171...... my f4i with a 45t max speedo 171
with a 65t again max speedo 171 (but actually only going about 100mph)

But if your going to run a 70t you might aswell get a 72t.
You will need the extra 2 teeth for when you bust yours out on the upper triple from the rediculous amount of engine brake

 

Yea I should have said at about 150, but its about 3 or 4% high overall.

 

i have a 65t on my f4i. it was choppy at first and the engine braking was too much, but as soon as i turned up the idle speed the engine braking reduced. the more you turn it up the less engine braking you'll have. i have no clue where my idle is set at cause i broke the cluster and have since turned it up.