Crankbait Bill Shapes Explained

Difference Between Square Bills and Rounded Bills

The main difference between square bills and rounded bills is their ability to get through structure. Round bills will gently roll as the bill comes in contact with structure. This gentle roll often exposed the baits treble hooks which makes it easy to get hung up. A square bill has sharp edges which force the bait to almost completely roll to get over the structure. This keeps the treble hooks away from the structure.

The shape of each’s bill has other functions that we will cover below.

How Round Bills Affect a Crankbait’s Action

A round bill is the most common-shaped bill you will find on a crankbait because of how versatile it is. You will find rounded bills on crankbaits designed to dive anywhere from 0-25ft deep.

The wider the bill is on a crankbait, the wider wobble it will produce. This wider action is more ideal post-spawn and when water is warm and fish are active.

Thinner bills produce a tighter, more compact wobble. This makes them more popular in colder water or when you need a more finesse presentation. In general, the colder the water the thinner you want your crankbait’s bill to be.

Some newer crankbaits are now coming with weight built into their bill to help it dive to their target depth faster. This helps the bait get and stay at its target depth longer.

How Square Bills Affect a Crankbait’s Action

The key to squarebills is how well they deflect and get through structure. This is why they are one of the most popular baits for targeting shallow water structures like laydowns, docks, or rock piles.

The reason squarebills work so well around cover is their flat lip doesn’t let the bait gently turn when it hits. Instead, it very abrupt and forces the bait to turn almost upside down as it goes over the structure. This keeps the hooks away from what it’s hitting and prevents them from getting hung up.

The short square bill prevents the bait from diving too deep, most dive less than 8 feet. It is at these shallower depths that have the most areas to get hung-up. This is why shallower baits often have a squaredbill.

How Coffin Bills Affect a Crankbait’s Action

Coffin-style bills look similar to a hexagon. They are a hybrid between a rounded and square bill. The nice thing about coffin-style lips is they offer some bests of both worlds.

Coffin lips will run deeper than a square bill while also being about to get through structure better than a round bill because of its clean edges.

How Wake Bait Bills Affect a Crankbait’s Action

Wake bait bills are very similar to a square bill but they are pointing much further down, almost perpendicular to the bait. These baits are not meant to dive deep. They stay on the surface or just below the surface. As water comes across the bill it causes the bait to turn side to side without diving down.

How Cupped Bills Affect a Crankbait’s Action

This is a more uncommon style of bill but some newer baits are starting to come out with it. Cupped lips are designed to create chaotic action. Because of this, you don’t need to create action with your rod, a simple straight retrieve will work. This makes cupped bills good for beginners.

How Circuit Board Bills Affect a Crankbait’s Action

Circuit board bills are made from the same material are the circuit boards in electronics. The key difference in circuit board bills is they flex. When they strike cover they absorb some of the shock and load up slightly, as a rod would. As it unloads off of the structure it can draw in a reaction bite. This style is good in pressure water where bass are used to seeing square bills bounce off cover every day and you need that slight difference in deflection.

Circuit board bills can be found in just about every lip style, it just comes down to the material they are made from.

Final Thoughts

When you go to a baitshop and are looking at crankbaits the first thing you should look at is its bill shape. The lip will tell you which type of crankbait it is and the action you can expect. Once you have the style picked out then you can decide if you want rattles/silent or what colors you want.