rear agitator effect on speedometer
Seasoned HDF Member
Joined: Jun 2005
Posts: 12,946
Likes: 32
From: Colorado Springs, CO
I just added an 18" rear wheel/tire, and when I stood it side by side with the 16, it looks to be about 2 inches taller.
I guess I'll have to use a GPS to measure speed and then know where the speedo is at.
~Joe
I guess I'll have to use a GPS to measure speed and then know where the speedo is at.
~Joe
Seasoned HDF Member
Joined: Jun 2005
Posts: 12,946
Likes: 32
From: Colorado Springs, CO
Tire is a D407~180/55B18 on my H/D Anarchy wheel
Stocker is a 180/65B16
Maybe some if it is that the stockers is at least half worn out, and thus has a bit of a flat spot in the center.
~Joe
Stocker is a 180/65B16
Maybe some if it is that the stockers is at least half worn out, and thus has a bit of a flat spot in the center.
~Joe
Seasoned HDF Member
Joined: Jun 2005
Posts: 12,946
Likes: 32
From: Colorado Springs, CO
Well, I use a PC-V with an Autotuner.
I'll just have to check the speed with a GPS, figure out the variance, and mentally make allowances for it when I ride.
~Joe
Seasoned HDF Member
Joined: Jan 2007
Posts: 20,616
Likes: 4,440
From: anacoco, la
using the tire calculator that i refernced in an above post, the 18 inch tire should have a diameter of 25.8 inches, while the 16 inch tire should have a 25.2 inch diameter.
so new tire to new tire, your 18 inch should be slightly more than 1/2 inch taller
so new tire to new tire, your 18 inch should be slightly more than 1/2 inch taller
Tourer
Joined: Nov 2011
Posts: 255
Likes: 0
From: Upstate, SC w/ my baby
I was looking into that wheel upgrade. I wondered about the same thing. I had to install a speedohealer on my Hayabusa just to get an accurate speed reading with everything stock. I will plan on the low profile rear tire combo.
Big Kahuna HDF Member
Joined: Mar 2010
Posts: 32,562
Likes: 2,577
From: Shit Weather USA
I went with a 18 inch rear,and according to the police radar on the side of the road it's off 2mph.
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Seasoned HDF Member
Joined: Jan 2007
Posts: 20,616
Likes: 4,440
From: anacoco, la
which way? is the speedo reading faster or slower than you are actually moving? if faster, i would ignore it and act as if it is accurate. we can all use a little 'cushion' from time to time.....