I have the parade fan on my road glide and was think about the smaller fan for the lowrider. The fan will cool the bikes down in heavy traffic. I was thinking about oil cooler but I would to see one with a fan to cool the oil.

 

I am running Amsoil and an oil cooler. This summer my oil dipstick thermometer stayed right at 200 degrees. The Amsoil alone will give you a good temp drop.

 

I've oil coolers on both bikes one has a thermostat the other doesn't. The one without does have a leather cover that fits over the cooler at temps below 50 degrees F. If you can keep your oil from hitting the breakdown point your doing some good. Also cooling the oil will also help to prevent some pinging by lowering engine temps. Use of synthetics will help also.

 

My preference for the fan is based largely on the added exposure to leaks with a cooler. The coolers do help and on 2 previous HDs the cooler was an improvement. In Fl it gets screaming hot in the summer and after 2 or 3 long lights my oil temps are in the 250 deg range. HD says not to worry that temps as high as 300 deg are acceptable and that is well within the heat range of a good synthetic. I just figured the fan will not leak oil.

 

I have the Perf-form oil cooler. It is the screw on type, once you buy it, you can take it apart and replace the elements inside it. It is a beautiful piece of aluminum. And we all like that, right.

I got it for my Yamaha 1100, I will let everybody know how it works, if interested. I live in AZ, so every little bit of cooling, especially in summer will help.

 

I happened upon a finned cover that goes over my oil filter and it dropped the temps about 10 degrees. But it is more of like a passive heat sink - doesn't work really efficiently unless wind is bowing over it, but still works since it is a heat sink.
I don't think an oil cooler is necessary, but if you have the extra cash it is always nice to have added oil volume and cooling.