toying between front (and rear) wheel/tire combos and am leaning towards a 21/18" with 140/180 tires...

the 21" up front is your normal 21x3.5" but the tire is not the more standard 120.
rather, I'm I'm planning to rub a super fat Metzeler 140/70-21.

regardless of fender clearance, what are my constraints with the factory ABS system?

same goes for the rear while we're at it...any issues there?
I'm under the impression a 180/55-18 is the same rolling diameter as stock?

this is on a 2014 street glide special...

thanks!
-a

 

As long as the wheel is designed around ABS it shouldn't matter about the tire. A larger tire will have more traction = lock up less. The ABS senses lockup, it doesn't care really why that happens.

 

^ no offense, but if you don't know how the system works, lets keep this thread to fact, not assumption.
I'm sure I'm not the only one you will want to to do this/have these questions as the 2014+ ABS models age, so this will be a good tool for the future.

the ABS system works with rolling diameter, so yes...it does matter.

 

with the linked braking system there are limitations Im not sure what they are but your doing the right thing by researching it first before you the money

 

there was a thread on here yesterday from hogpro about this

 

https://www.hdforums.com/forum/new-r...bs-2014-a.html

and

https://www.hdforums.com/forum/new-r...kes-issue.html

 

Not sure that Fat 140/70-21 will fit as it has the same diameter as standard 23" tire!
I have seen one pic of it fitted to stock fender and looked a very tight fit, really should have 23" fender and trees with that tire, not a quick cheap makeover!

 

You need to keep the two wheel withing 10% overall diameter of each other. The 140 is going to need some sort of fender designed for a 23" wheel as it is much taller than a standard 120/70/21 tire which requires a bracket on the stock fender on the 14 and newer models.

According to a a chart I found the overall diameter is 28.72. Thus whatever wheel you run on the rear is going to need to be within 10% of 28.72. A 180/55/18 (need a new rear wheel 18x5.5 is overall diameter of 25.8 which makes it more than the 10% you need for your abs and linked braking to function properly thus at this time there is no way to do this and keep the ABS system intact. For what you want to do eliminate ABS and linked brakes and call it a day or adjust the sizing that you want.

Here is the calculator I used. I don't really trust it as I ran some other numbers and they did not seem correct. I'll see what else I can find.
http://www.tacomaworld.com/forum/tir...5r18-140-70r21

 

So really what we need is overall circumference, not overall diameter. My mistake on the wording.

 

no comment on the abs, but your 'impression' on the 18'' rear tire is wrong. the 18'' rear tire will raise your rear end about .3'', the overall diameter will increase by .6''. so it doesn't really raise you much but overall, the diameter is bigger by 2/3''