There are a number of different methods for constructing a bike polo mallet, and there has been much innovation over the years. Starting out with half of a crutch, to bamboo, to ski poles with wooden inserts, to the modern T-nut construction innovated by Eric Crandall.

The most important step in constructing a mallet is choosing a strong, yet light ski pole. Used sports stores, thrift stores, and ski lodges will often have poles for sale; you should pay under five US dollars per pair. To select a good ski pole, use the following steps:

Measure the length of the mallet from the top of the handle to the top of the basket. Most people use mallets in the high thirty to low forty inch category.
Check the material - aluminum or steel are good, carbon or bamboo should never be used. Titanium is a toss-up - some people like it, some don't due to its flexibility.
Check for kinks in the mallet. Scratches are OK, but a kinked mallet is a doomed mallet.
Test the strength of the mallet by flexing it over a knee. This will take some practice to get a feel for it, but it should take a fair amount of effort to bend the mallet. Too flimsy and it will break quickly.

Once you have selected your mallets, you will need mallet head material. There are many different grades of ABS and HDPE piping, and the main differences will be in weight and durability. I personally like a light mallet, so I use two inch (interior) cellular core ABS. This will wear out quickly, but thanks to the T-nut technology, you can replace mallet heads easily.

Tools needed: drill, screw, razor blade, hacksaw, pliers, 2.5" T-nut and bolt, desired wrapping material.

Step 1: Prepping the Mallet - the Grips

First off, we want to strip off all the extra ski junk off of our mallet. Begin by cutting the grip off of the pole. Sometimes you can just yank them off, but it is a lot easier to cut.

Step 2: Prepping the Mallet - Cut to Length

The next step is to cut your mallet to size. Generally ski poles have a thicker diameter towards the bottom of the pole, so we want to measure from the top of the basket up. With a hacksaw, cut off the basket, and trim the top of the mallet, if needed.

Step 3: Prepping the Mallet Head - Cutting

With a hacksaw, cut your mallet head material into a usable length. I prefer 4.5" mallet heads, some prefer larger.

Step 4: Prepping the Mallet Head - Drilling and Mounting

There will be a total of three holes drilled into each mallet head: two for the shaft, one for the bolt. Choose a drill bit equal to the size of your mallet shaft, center it up, and drill straight through both sides the mallet head. You want it to be a tight fit, so always err to a slightly smaller size.

Insert the shaft into the hole and push it on through, pounding on it with a rubber mallet if needs be. The tip of the shaft should be flush with the outer edge of the other hole.

Step 5: Tapping the Shaft

If you are using a 5/32" and 8/32" bolt and T-nut combo, you will need the same diameter drill bits.

Rotate the mallet assembly 90 degrees, center up, and drill a 5/32" bolt-hole through the mallet head. If you have a short drill bit (nothing to be ashamed of), push down enough to make a mark on the mallet shaft and pull out. This will ensure a straight fit.

Pull the mallet head off of the shaft and drill straight through the shaft at your mark, using a 5/32" bit. Then with the 8/32" bit, widen out one side of the shaft only.

Step 6: Assembling the Mallet

Put the mallet head back on the shaft and align so that the 5/32" hole in the shaft is facing the 5/32" hole in the mallet head.

Put the T-nut into the 8/32" hole and thread the bolt through the head and shaft, into it. Once the threads are engaged, hold onto the T-nut with a pair of pliers and screw the bolt all the way in.

At a certain point the bolt will be hitting the other end of the head and just start to push its way through - if you stop just before total penetration, a little plastic bubble will cover the sharp threads.

Step 7: Wrapping the Mallet

There are many ways to wrap a mallet, from hockey tape to used bike tubes. For this project I decided to finally learn how to tie some knots and did a paracord wrap. There are many great instructables and books out there for paracord, so I'll leave you to your own devices. I got these knots from the books, "The Marlinspike Sailor" and "Creative Ropecraft".