Here is how I change a head. First take off the resonator if there is one, then the strings, bridge, tailpiece, and tension hoop. I use a standard 1/4 inch nut driver to loosen all of the brackets. This is the most common size, but you may have a banjo that uses either a 3/8" or metric driver or wrench. When the head is off I always check the fit of the neck and the tightness of the rim rods. The neck should be snug to the rim, but not tightened so tight that the wood in the rim is compressed. The bolts on coordinator rods at the tailpiece end of the banjo should be hand-tightened so that they are not pulling on the rim (more later on this).

I often take this opportunity to completely disassemble my banjo so I can check the way all of the the pieces fit. I also clean the metal parts with a good metal cleaner. My banjo is a recent model Gibson so I don't worry much about making it not look “original”. If I had a 1937 original Gibson flathead I probably wouldn't do anything that might remove or change the look of the metal parts. By taking the banjo completely apart I can also make sure that everything is tightened the correct amount and all the pieces line up correctly. This way I can start from a stable platform that I know will be consistent with my previous setup.

Different brands of banjos often have different method of attaching the neck. On the standard Gibson design there are two rods. The lower one (closest to the resonator) is attached using a long bolt that is drilled and threaded at both ends. One end screws into the lag bolt in the neck. This actually holds the neck on. A coordinator rod screws into the other end of this “bolt”. The other end of the coordinator rod passes through the rim where the tailpiece is located. There are small nuts on the inside and outside of the rim to hold it in place. These bolts do not have anything to do with holding the neck on! They should be hand tightened so they do not exert any pull on the rim.

There are several variations on how necks are attached. Most non-Gibson banjos made today use 2 coordinator rods without the long bolt. I've found that this tends to give the banjo a more “solid” sound by eliminating the joint between the rod and the long bolt. It's easy to replace the rods if you have this type of connection. Some banjos, including some older, cheaper Gibson models only have 1 rod and just use a regular bolt to hold the other lag bolt on. Finally, you can also find banjos with no rods, just 2 bolts. This is often true with travel banjos making them easier to take apart. This isn't a great way to attach the neck in terms of sound quality.

The upper cooordinator rod screws directly into the neck lag bolt and should be tightened firmly at that end. I use a small Allen wrench that fits in the hole in the middle of the rod and is short enough to be turned to tighten it. The other end fits in a hole in the rim and only has a nut on the inside of the rim. Like the bottom rod only the end attached to the neck holds the neck on so you should finger tighten this bolt as well.

Here are 2 photos showing the coordinator rods and my way of tightening the bottom rod.

       

I talked earlier about checking the tightness of the coordinator rods when changing the head. I'd like to give you my opinion about using them to adjust the banjo's action. I'm a firm believer in not using the rods to change the string height like some setup instructions recommend. I'm not saying that you should never do this, but it should only be used for small adjustments that can't be done any other way.

This technique adjusts the action by changing the shape of the rim. This is done by changing the effective length of the bottom coordinator rod (the one the usually has the tailpiece bracket bolted on the outside of the rim). By tightening the bolt on the outside, or tightening the long bolt if you have one to do the same thing you're pulling the bottom of the rim closer together. This in turn pulls the neck down lowering the action. Tightening the bolt on the inside of the rim or loosening the long bolt raises the action by pushing the bottom of the rim farther apart. Either of these adjustmens pulls the rim slightly out of round which makes it harder to tighten the head evenly. It can also affect the fit of the tone ring which will decrease volume and tone.

The best way to raise or lower the banjo's action is to use a higher or lower bridge. If you have an older, less expensive banjo you may find that the holes through the rim for the lag bolts are slightly bigger than the actual bolts. You may be able to move the neck up or down slightly before tightening it up making a small difference in string height. Also, there may be enough play to allow the neck to twist a little when it is tightened causing the neck to be higher on one side of the other. Be sure to check this before tightening the neck. You may need to check these adjustments after putting the new head back on so you can line things up with the notch in the stretcher band where the neck is attached.