Top Speed ???
05-30-2010, 10:47 PM
#1
Junior Member
Squid
Thread Starter
Join Date: Apr 2010
Posts: 5
Top Speed ???
New guy here. New to the SH as well.
I had a chance / reason / excuse today to open the hawk up on a long straight road with little trafic. My understanding is these things do about 150 mph tops. I didn't quite top it out, but it indicated 170 mph
. Held that speed for about 5 miles.
I bought the bike, a 2001, with D&D slipons and dont know what else. I took the rear sprocket up two teeth. It only had 4000 mile on it so I assumed it was basically stock.
What else could the previouse owner have done to make this thing run that fast?
I had a chance / reason / excuse today to open the hawk up on a long straight road with little trafic. My understanding is these things do about 150 mph tops. I didn't quite top it out, but it indicated 170 mph
. Held that speed for about 5 miles.I bought the bike, a 2001, with D&D slipons and dont know what else. I took the rear sprocket up two teeth. It only had 4000 mile on it so I assumed it was basically stock.
What else could the previouse owner have done to make this thing run that fast?
05-30-2010, 11:03 PM
#3
Banned
MotoGP
Join Date: Aug 2007
Location: Lake View Terrace, CA
Posts: 5,942
It's just the speedo being a bit optimistic....... I've had mine to the rev limiter in 6th (10.3k rpm) and calculated a true top speed (gearing, tire diameter & RPM) of 157 and the dyno says a top speed of 159 and the needle was buried past 180mph both times..... So an indicated 170 is around 135-140mph.
05-31-2010, 06:45 AM
#5
Out of my mind, back in 5
MotoGP
Join Date: Nov 2006
Location: Skurup, Sweden
Posts: 6,109
New guy here. New to the SH as well.
I had a chance / reason / excuse today to open the hawk up on a long straight road with little trafic. My understanding is these things do about 150 mph tops. I didn't quite top it out, but it indicated 170 mph. Held that speed for about 5 miles.
I bought the bike, a 2001, with D&D slipons and dont know what else. I took the rear sprocket up two teeth. It only had 4000 mile on it so I assumed it was basically stock.
What else could the previouse owner have done to make this thing run that fast?
I had a chance / reason / excuse today to open the hawk up on a long straight road with little trafic. My understanding is these things do about 150 mph tops. I didn't quite top it out, but it indicated 170 mph
. Held that speed for about 5 miles.I bought the bike, a 2001, with D&D slipons and dont know what else. I took the rear sprocket up two teeth. It only had 4000 mile on it so I assumed it was basically stock.
What else could the previouse owner have done to make this thing run that fast?
Two teeth up on the rear sprocket is a 4.7% change rounded off to 5%... And then considering the speedo is usually about 10% optimistic to begin with, that's a 15% error give or take... Say 13% at best, 17% at worst (8-12% speedo error)... So you where actually travelling at a speed somewhere in between 140-148 when your speedo said 170... That's a fairly typical for a VTR...
05-31-2010, 09:16 AM
#7
Out of my mind, back in 5
MotoGP
Join Date: Nov 2006
Location: Skurup, Sweden
Posts: 6,109
Ah, I knew I had forgotten something...
That makes 125-140 mph then...
But actually 5-10% seems a bit high... From what I have read, a bit less is usually the case... But it's still a far cry of the 170 that the speedo reads...
Also at that speed you should probably take into account that the tire will grow enough to actually impact the roadspeed
That makes 125-140 mph then...
But actually 5-10% seems a bit high... From what I have read, a bit less is usually the case... But it's still a far cry of the 170 that the speedo reads...
Also at that speed you should probably take into account that the tire will grow enough to actually impact the roadspeed
Last edited by Tweety; 05-31-2010 at 09:19 AM.
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