Harley has and does make liquid cooled engines.
Like the liquid-cooled Street range of 500, 750 and Street Rod and the VROD
While I am by no means an expert. I would say it is a heritage thing for Harley.
Several other manufacturers with proud air-cooled histories including Ducati, BMW and Moto Guzzi.
I know that it is getting tougher for air-cooled engines to meet emissions, but I'm sure Harley will do what they can to extend the air-cooled life.

just my thoughts and I am most likely wrong :P

 

Harley has made Liquid Cooled engines. The V-Rod and the Street 500 and 750 are liquid cooled, and they have a new engine coming out next year called the Revolution Max that will power a whole new line of bikes including an Adventure Bike and a Cafe Racer. The V-Rod and Street didn't sell very well. Harley customers want an air cooled engine.

Is there a drawback to liquid cooling, yes it's more complicated, if the liquid cooling system fails you ruin the engine, don't do the maintenance and change your antifreeze every couple years and you will get massive corrosion inside the engine. Oh and when you change out the fluid don't get an air bubble in the system because you didn't read the manual and purge it properly, you'll end up with a blow head gasket and a cracked head.

Is there advantages to liquid cooling? of course, that's why almost all cars are liquid cooled. Liquid cooling keeps the bike at an optimum temperature, makes it easier to meet emissions regulations

Like SS3964SPD said, overheating is generally not a problem. I to live in the Washington DC area with heat and humidity. I commute to work on my Sportster (well I did when I could go into the office) Our Legion Riders Chapter rides in the Fairfax City 4th of July parade every year (as well as several other parades), as does HOG, the Shriners, and the local PD's. All on Harley's, all at slow stop and go speeds. Yeah the bikes get hot, but rarely does one overheat.

An air cooled bike overheating is not a problem unless you are sitting still and there is no air flow over the cylinders to cool it down. If you are sitting still that long just shut the bike off. If you are going to be commuting every day in stop and go traffic, you might want to get a liquid cooled bike, although I haven't needed one yet.

As for you comment about other manufactures not making air cooled bikes, many if not most of them do make at least a couple models of air cooled bikes. Heck in 2018 Yamaha came out with their flagship touring bike, guess what type of engine it has? Yep an air cooled V-Twin. Yamaha did a lot of research, talked to a lot of their current touring bike owners and overwhelming response was they wanted an air cooled engine.

 

Harley has been walking the same tight rope for years; how to improve performance, meet emission standards, boost market share by appealing new customers, incorporate technology, all while not alienating their core demographic. A tough row to hoe.

 

Yep. I have said this before, but this is EXACTLY the issue Cadillac had. It almost killed the brand as their core demographic died off. Same issue that also brought us the 2020 mid-engined Corvette. It can be done, but it is tricky. Harley needs to take a look at what GM has done.

 

And NOT do that. But maybe you mean what GM has recently done.

 

LMAO... you make a good point. What they have RECENTLY done.

 

The new M8 Softails do have liquid cooling. It's not water/antifreeze. It's oil. They increased the oil capacity by about 2 quarts and incorporated an oil cooler in the frame directly aft of the front wheel. Yep, it gets HOT in stop and go traffic (which I avoid), but the engine can take it. Don't worry, be happy and get an M8 softail.