The nemesis of any air-cooled engine is not necessarily the ambient air temperature, but rather the airflow. As anyone who has participated in a bike parade or been stuck in traffic at a major rally knows, if you ain’t rolling that motor is gonna get mighty damn hot even if it’s only 80 degrees. Toss in the crap gasoline we have to deal with these days and the problem escalates. To address the predicament of deficient airflow, the engineers at UltraCool have developed a line of fan-assisted oil coolers specifically designed for the V-Twin crowd. And their new Reefer model is at the top of that product line, utilizing twin fans and a beautiful chrome housing that accents your bike instead of distracting from its appearance.

The Reefer tucks nicely beneath the voltage regulator
The Reefer tucks nicely beneath the voltage regulator

The Reefer is designed to fit the Street Glide, Road King, Road Glide, Electra Glide and H-D Trike models. (The RF-1 fits 1999-2008 while the RF-2 is designed for 2009 and newer bikes. Alternative versions are also available for Softails.) Installation of the Reefer is straightforward with some of the most user-friendly instructions I’ve ever encountered in a project. After draining your oil and removing the filter, clean the filter base of oil and grit. A two-piece adaptor is then taken apart with the internal section being attached to the threaded filter spigot and sealing on the filter gasket surface. The second half of the adaptor is then reattached using the six hex bolts (thread locks recommended). The oil adaptor is finely crafted and finished, with internal cavities that channel the oil through the filter first and then reroute it through the cooling fixture. This rerouting also causes the oil to course over a thermostat switch that monitors oil temperature. The installation of the adaptor is permanent with no need to remove it in the future.

The "magic" of the Reefer is the twin fans that kick in at 220 degrees
The “magic” of the Reefer is the twin fans that kick in at 220 degrees

Next on the list, remove the nuts securing the voltage regulator to the frame’s front cross member, raising the regulator up high enough to access the mounting studs. (Since you’re in this deep, go ahead and inspect the engine’s front mounting bushing and replace if needed.) Slide the Reefer mounting bracket plate over the regulator’s studs, place the regulator housing back in place and reinstall the two nuts. Remove the chrome cover from the fan module and bolt the fan assembly to the bracket with the two button-head cap screws. Hand tighten only, as you will come back later to make adjustments and to install the cover. Install the two braided steel oil lines to the end of the twin fan assembly. Route the lines according to the instructions (pay attention to which lines go where) and connect them to the oil adaptor. A special open-end, crows-foot wrench is included for this part of the operation. The fan’s electrical conduit is then snaked behind the voltage regulator and the two female spade connectors attached to either side of the thermal switch. The balance of the conduit wiring is run up the left side of the frame, securing it with tie wraps along the downtube. Slide the chrome cover back over the twin fan unit, apply some thread lock to the bolts and secure.

The conduit is run inside your bike’s fairing for two purposes: to access a power source for the fans and to install the LED indicator light. This light is illuminated whenever the fans are activated. (And figuring out exactly where you want to install the LED may be the most difficult part of this entire process.) After drilling a hole in the fairing and installing the LED indicator, it’s a simple matter of sorting out the remaining wiring, splicing in the included fuse holder and hooking the entire harness up to the bike’s existing headlight hot wire as indicated in the instructions.

The unit's stainless braided oil lines are almost hidden from view
The unit’s stainless braided oil lines are almost hidden from view

Install a new oil filter on the adaptor and add oil as required. Start the bike, let idle for a few minutes, kill the bike and check for leaks. Then go for a two- to three-mile ride, stop and check for leaks again. It is recommended that after an initial ride and allowing the bike to heat up and cool down that you check the four adaptor hex bolts that lie along the outside perimeter of the oil filter (the other two are behind the filter and cannot be accessed without removing the filter).

The Reefer uses a 17-row heat exchanger located behind the dual fans to cool the oil. The oil is constantly flowing through these fins whether the fans are activated or not. But when the oil temperature reaches 220 degrees (think Main Street Sturgis, South Dakota), the thermostat switch detects the increase, completes the circuit and sends power to the two 150 CFM fans that blow air through the heat exchanger, dropping the oil temperature to 190 degrees before shutting off. (Allowing a motor to heat to 210–220 degrees is considered the ideal temperature to burn off internal condensation.) So whether you’re moving or not, that oil is receiving a constant blast of motor-saving air.

The fans are whisper quiet and the only time you will know they’re running is by the LED indicator (the indicator can be mounted in a multitude of locations in case drilling a hole in your fairing is not suitable to your tastes). Plus the airflow created by the dual fans is down low, under the bike and not directed towards the bike operator. The effectiveness is obvious with a reduction in engine ping and knock and better performance due to consistent operating temperatures. The peace of mind it delivers alone is worth the investment.

The adaptor is machined from 6061 aluminum and is an excellent piece of craftsmanship, fitting perfectly with no misalignments. The dual fans are water resistant and dustproof, while the all-vital thermal switch is rated at 100,000 cycles of service. Installation averages about two hours and only requires basic hand tools. An easy-to-install unit that looks this good and works this efficiently should be at the top of every bike owner’s “must-have” list. You owe it to your motor.

Reefer Oil Cooler
UltraCool Oil Cooling Systems
Model RF-1 $399


  1. I bought this I love it works great had a little issue with the temperature switch not coming on call the company they sent me a new one right away I want to say thank you to them I love this product

  2. I have an ultra cooler on my 99 flht,the tail bearing failed and sent pieces thru the entire engine.HAVE TRIED TO clean out cooler with no success.Is it possible to get just the cooler core?


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