[Busy Little Shop]

Mr.RC45 came stock with a 16 and when I raced it the 130/70/16 was
quick on the steering and meaty on the contact patch... when I
switched to a 17 magnesium Marchesini for lightness and ran the latest
rubber the new 120/70/17 slowed down the quickness of the steering
dramatically... to gain back the same quickness required a complete
different set up... so it doesn't matter the rim size when you take
the time and do a rake and trail study of your bike and then change
the set up to gain the desire of quickness...

To find the diameter of any tire size use my handy formula...

tire width x aspect ratio / metric conversion + rim size = diameter

130 x .7 x 2 / 25.4 + 16 = 23.16 inches or 588mm...

120 x .7 x 2 /25.4 +17 = 23.61 inches or 600mm...

So this drawing I made on my wall shows the diameter difference
between a 130/16 and a 120/17 is 12mm or .472 of an inch... what Honda
engineering did was split the size of the 120/70 and the 120/60 17
with a 130/70/16... if the tire companies would cooperate I believe
the 16 has chance for a strong come back... what gave the 16 a bad
name was the flexy frame of the Honda CBR900RR... when slapped on some
sticky rubber the frame just through in the towel...

 

[Busy Little Shop]

On 996/998 Duc's we used to run a 120/60 tire on the front..it helped turn in effort quite a bit..On the CBR900rr's the 16" front made it turn faster, but it sure was hard on the wrists/arms.

True... a 20/60 tire will do that because the smaller diameter wheel
will effectively tuck the rake and subtract trail as a matter of
geometry...