Modulus Ratings of a Rod

When purchasing a rod, it seems that most manufacturers try to sell there product based on modulus ratings. Modulus is a term used to describe the stiffness to weight ratio. An elastic modulus is the mathematical description of an object or substance’s tendency to be deformed elastically (non-permanently) when a force is applied to it. Therefore when a blank increases in modulus ratings, it is also increasing its ability to store & release the energy it stores when flexed via a cast or fish. The higher the (true) modulus of a rod is, the lighter and more sensitive it will be. With an increase in modulus, cost increases and resilience decreases.

While this seems logical to use as a selling point to sell more rods, as some do with their IM6 modulus rating, IM7, IM8…etc. as far as I know, there isn’t an industry standard to define modulus rating in graphite, but rather based more on a range depending on the manufacture formula. Therefore one rod may be rated the same as another, but could be less expensive because it is a lower modulus blank. Just because a rod is expensive and has a high modulus doesn’t ensure that the blank design is the right one for the application you are looking for. Many blanks are designed for a specific fishing technique, where others are a standard blank with the intended application/technique of the rod not factored in, i.e. technique or species taken into account. Other factors to consider in blank design are length, diameter, taper, wall thickness and material along with how the material is placed on the mandrel to create the blank. All factors above will determine the rods action, taper, weight, and strength.

While all of this can be somewhat confusing, it’s best not to get caught up in all of the modulus hype and just use a rod that is designed for the intended technique. When properly done, the angler can expect to hook up with more fish by being able to feel the strike faster as in jig fishing or in some instances slower, such as using crankbaits, which allows the fish to inhale the bait.