i have a 07 nitetrain im being told i need to put a oil cooler on it, is this really ness.

I would think that it depends on the type of riding that you do. First I run synthetic oil in the engine and all the other wet areas. If you ride in heavy traffic all the time, stop and go and the engine starts to overheat that is certainly the way to go. If you ride for fun and are out rolling most of the time I think that you are good to go. Just logical thinking.

need a little more info:
who told you you needed a cooler?
and all the questions the previous posts asks...

One thing I like to run on most all my bikes is a oil temp gauge. Makes me feel a little better knowing how hot the oil is and the danger zones of when to get to a cool off place. Too many hot times and you probably need an oil cooler. In the wind.

Pops

Only problem with an oil cooler is you really don't get much benefit in traffic...the bike needs to be moving for it to yield anything. However, I've heard the average oil temp is as much as 25 degrees Farenheit lower which would seem to offer an overall positive benefit..

I've been considering one for my SG....

I just bought a Ultra Cool oil cooler for my 06 Ultra Classic. Dual fan, thermostat control. All reviews sound great. If it works half as well as the reviews say I'll be very happy. Price is a little over $400 but I searched the Internet and found it for $323.

My 2012 Ultra and 2015 both came from the factory with oil coolers. I don't think an oil cooler can hurt. Don't think its a necessary got to have either? I think HD may put them on their '12 on up because of the 103" and any cooling has to help at that point? I'm glad to have one and from the factory too.