i bought an 02 hawk this winter and the sprockets have been changed. it turns about 4500 rpm's on the highway at approx 70 -75 mph, and the nmileage is lousy (less than 25mpg) i dont know how many teeth on the spocket (haven't counted them up yet). i've read about speedo healers. are they hard to install? i'm also thinkin about changing to a less aggressive sprocket too. any thoughts on that? how many rpm's does a stock hawk turn on the highway at 70 mph? thanks, bob

 

16t front, 41t rear. 4K rpm,@ 70 +/- in 6th. Check that your choke is completely disengaging after you start the bike when cold and have your carbs been balanced? The last mpg item is the tps, check that it's set to 4-6 ohms.

Gentle throttle control and a lubed chain got me as high as 44 mpg.

 

I'd guess it's setup with 15 tooth front and 43 tooth rear...take a GPS with you and compare that speed reading to your speedo. If there's a difference and you don't want to go to stock gearing 16/41 then you can get a speedo healer to fix it:
http://www.speedohealer.com/eng/order.htm

Good luck bro!
RC

 

just picked one up and verry EZ to install and theres a max speed recorder it a cool thing

 

hide the max speed button from the fuzz

 

mine is doing worse, the PO put on a vortex setup, it runs about 5k rpm at 83mph(speedo reading) but the guys i ride with say we're doing 65mph... and my odometer is going crazy...
where did you get your speedo healer?

this is all i could find:

$$$$$

are there any cheaper?

 

that's actually a pretty good price

 

If it could pull it the VTR with stock sprockets would redline (9500 rpm) at 169 mph in sixth gear.

To find rpm at 70 mph? 9500/169 =56.21 (rpm per each mph) times 70 (mph) =3935 rpm@ 70 mph.

Here's the formula;

(rpm X #front sprocket teeth X tire circumference in millimeters) divided by;

(primary gear ratio X sixth gear ratio X #rear sprocket teeth X 26,817)

nominal tire circumference for 180/55/17 is 1975 mm

Also, gear ratios are on pg. 204 of the owner's manual. If you don't have one, primary ratio is 1.681 and sixth gear is 0.961
Plugging the sprockets you have into the formula will give you actual sixth gear road speed at given engine rpm.

 

helpful... but where do i mount a calculator on my bike?

 

Ha! Has to be a decent calculator also, not one of those 8 digit cheap ones.

I use the one on my computer to determine rpm at given 6th gear cruise speed, percentage error from stock etc.

Then I use the one mounted between my ears to keep track of how fast I'm actually going.

 

Instead of spending $110 for the speedohealer, you can order a $15 bike computer and get the same results, http://www.ldrider.ca/techpages/bicyclecomputer.htm

The only thing it does not have is a light to read the speed at night.