Just bought a 2014 Street Glide with a 23" front wheel and I've got the ABS issue as well. Took it to the dealership I bought it from, Dallas Harley Davidson and they're going to look into it. Would appreciate any info anyone has to get this resolved.

 

I forgot to update this. It seems that the overall diameter of both tires cannot be more than 10% different. On the original bike we put a 200/55/17 in plate of the 200/50/17 and that cured the issue. I just talked to the service manager at Fort Worth Harley about it yesterday. So, with a 120/70/21 and a 17 on the rear ensure it is a 20/55/17.

With a 23" we will probably have to try the Vee rubber 23" front tires as it has a lower sidewall profile than the Avon Cobra which is a 130/60/23. I can't remember the sidewall profile on the Vee off the top of my head. It seems running an 18" rear would probably help as well but I have not crunched the numbers on this yet.

 

I'm new to the forum but I've been following this topic for a while. I have the same problem with my '14 FLHSX with Avon Cobra 180/55/18 rear and a 130/60/23 front, both mounted on RC Components Calypso wheels. Both have HD bearings. As long as I keep it below highway speeds the ABS light stays off. It seems that as rpm's increase, the controller reads the increased disparity between the 2 wheels as a malfunction and shuts down the system. If it were as simple as a minimum 10% difference between the 2 diameters, wouldn't it be the same at any speed?

 

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"It seems that the overall diameter of both tires cannot be more than 10% different."

Anyone know how to calculate this 10% difference?

Front tire is 130 / 60B 23
Rear tire is 180 / 65B 16

Front wheel is 23 x 3.75
Rear wheel is 16 x 5.5

I also tried the:

"ride the bike for 10 miles or so at less than 50 MPH without stopping if possible and the computer should reset itself."

and that didn't work for me either.

 

Here are the percentage differences in the two tires..

Side by side Overlay
130/60r23 vs 180/65r16 Tire Comparison Side By Side
130/60-23 180/65-16 Difference
Diameter inches (mm) 29.14 (740.2) 25.21 (640.4) -3.93 (-99.8) -13.5%

Width inches (mm) 5.12 (130) 7.09 (180) 1.97 (50) 38.5%
Circum. inches (mm) 91.55 (2325.41) 79.21 (2011.88) -12.34 (-313.53) -13.5%

Sidewall Height inches (mm) 3.07 (78) 4.61 (117) 1.54 (39) 50%
Revolutions per mile (km) 692.07 (430.03) 799.92 (497.05) 107.85 (67.02) 15.6%

 

Here are the percentages of your factory set-up

130/60-19 180/65-16 Difference
Diameter inches (mm) 25.14 (638.6) 25.21 (640.4) 0.07 (1.8) 0.3%
Width inches (mm) 5.12 (130) 7.09 (180) 1.97 (50) 38.5%
Circum. inches (mm) 78.99 (2006.22) 79.21 (2011.88) 0.22 (5.65) 0.3%
Sidewall Height inches (mm) 3.07 (78) 4.61 (117) 1.54 (39) 50%
Revolutions per mile (km) 802.18 (498.45) 799.92 (497.05) -2.25 (-1.4) -0.3%

 

Thanks Joe.

I found a tire calculator and my numbers match yours.

Basically Stock front and back height are the same:

25.1" high 130 / 60 /19 in the front
25.2" high 180 / 65 / 16 in the back

with my setup I'm 4" higher in the front than the back (13.4% taller)

29.1" high 130 / 60 / 23 in the front
25.2" high 180 / 65 /16 in the back

It looks like to get below the 10% I would have to go to a 17" wheel in the back (180/65/17 = 26.2") and that would put my percentage at 9.965%. So I wonder how accurate this less than 10% rule is???????

 

Which tire size calculator are you using?

 

http://tire-size-conversion.com/tire-height-calculator/