Have one on each bike, it's like insurance. If HD doesn't think the bikes are running a little on the hot side, then why are there oil cooling jets directing oil to the underside of the piston crown? It can get warm here but sometimes the bikes are being ridden somewhere where it's very hot, i.e Biketoberfest and its traffic or Sturgis in August.

 

Oil coolers are great however the time you need it the most, sitting in traffic, they dont work real well since there is no air flow. To get around that I use the Big Sky Fan Kit and I can sit in traffic all day and not overheat.
Quigley

 

how hard are they to install?

 

Jagg are considered the best in oil coolers. The H-D one is supposed to be very good also. I think if you live in a warm climate, or have built your motor, it probably isn't a bad idea. Definitely want one with a thermostat. They are very easy to install.

 

On the 05-earlier dynas you can put the old style shovelhead lockhart oil cooler on the front downtubes without interfering with anything. There's a hole already there for it just like the old shovelhead frame. I run one with a thermostat oil filter adapter and it works as good as anything else. Don't have to worry about road debris and it's right up there in the airflow. Here's a pic of it, excuse the large dog in the foreground.

 

I have this vague recollection from back when I was more into high performance auto stuff, that oil coolers can result in a reduced oil pressure, due to the need to move the oil thru the cooler (or something). Is that just some old wives' tale? Does anyone know if adding an oil cooler really does reduce oil pressure?

 

Sounds like "an old wives tale" to me. I got a deal on a new HD cooler for my Train. It's practically invisible and really makes a difference on oil temp. I'd say 20+ degrees lower and when it's 115 out that's important.

Can you see it right behind the clutch cable?

 

I don't believe they are really that necessary, but certainly don't see how they could be a Bad idea.

 

my only thought on the oil cooler is that if your not moving the oil cooler is not going to be much help either... to me it just becomes an ugly add-on that sticks out like a sore thumb ( just my opinion) now for stop and go you can get a inconspicous fan that you can mount between the frame!!! if i had a cooling issue i would go this route first along with maxing sure i have the right oil and the making sure the bike was tuned proper.. a oil cooler would be my very last resort...

 

Thats where the Big Sky Fan Kit comes in. Two water and dust proof fans keep the oil cool while sitting in traffic.
Quigley