I just got done reading that also. On page 48 they are even suggesting the use of TWO Jagg coolers.

 

In poorboy's defense I've read various articles on the subject including a "sticky" here in the tech forum that pretty much echoed what poorboy said. Two main things I recall that have thus far disuaded me from getting one are that they are ineffective w/o a fan and they add a point of failure. I recall recently that twiggyaz installed one on her Deluxe and wasn't happy with the results. I don't know if her issues with it were ever resolved or not.

But Citoriplus indicates that he's had good results with his. And I also read the article in American Iron which was very positive. At least for certain types of oil coolers. So it seems there may be good cause to take a second look at them.

 

I had my cooler installed by the stealer with the oil pressure gauge, pipes and intake. All was done so the warranty would cover it on a new bike. With that being done, I don't worry about the engine at all. I'll invest a little to ensure the engine is protected in one more way. And, if you can cool an air cooled bike a few degrees it pays big dividends on those hot days in the south.

 

Pic didn't attach...my cooler pic so you can see what it looks like on a Rocker.

 

I thought of going with H-D cooler then found this one and decided to give it a try. Ended up being a little pricey by the time I got everything together. Chrome plated billet oil cooler, Jagg thermostatic adapter and 10' of ss braided hose w/clamps-$370. Went this way mostly because I like the look and the ability to mount inside or outside the downtubes. At least on my bike. Before the oil cooler I was seeing 245+ oil temp at 70mph. Now I'll see 220. This with the air temps in the upper 90's. I would definitely recommend an oil cooler to all those that are undecided. At least run full synthetic and change often. Stock I saw 260 temp often. Cruising the beach I once saw 276. Scared the hell out of me even though I was running syn at the time. No oil cooler will stop oil temps from climbing if you get into a bunch of stoplights but it will cool down more and faster w/cooler when you get moving. I'll try and post pic. Sorry, got lazy and used cell phone pic.

 

If you decide to buy a 7/16 allen here is the part number from Grainger.

PART# 1EZN3 $7.47

I also used Permatex High Tack Spray a Gasket to hold the adapter gasket in place.

Other than that the install is simple. The Gasket can only go on one way but the directions suck on how to align it. I added 3 Ft/Lbs to the torque spec. The adapter would wiggle at the recommended amount.

Temps are 10-15 degrees lower. Temps are now 200-215 F. The best part is if temps climb in stop and go the cooler will aid in dropping 5 degrees upon moving again where as without a cooler once the temp rose they would not drop until I stopped and turned the engine off.

IMO worth the cost but not a must have!