Spools and Spool Tuning

Great questions.

1. Spool diameter is what’s most relevant followed by shaft diameter, and length. You can use spacers in many reels to allow use of a smaller diameter spool than the standard. There are several companies out there that provide spacers. ZPI used to make them, but stopped some years back. You can still find sets here and there on the second and market, or contact other manufacturers that are machining them. Other spools with shorter length shafts can be utilized in certain reels by swapping out the pinion shaft that slides into the reel from the cast control Side.

2. An inductor is the cylindrical cup, that moves in and out of the magnet rings/magnetic gap that are mounted inside the palm plate of Daiwa reels. Its thickness, depth and sometimes taper, (along  with spring strength and mag assemblies) are what determine the braking profile. The longer an inductor is in the magnetic gap, the more brake force is applied. There’s a lot more to this, but I won’t dive into crazy amounts of detail.

3) Tuning a spool usually involves quite a few things, but I’ll use Daiwa/Magforce as my example since I tune more of these spools than any other. Bearings, type of oil, inductor spring and inductors themselves are the main things I mess with. Oil weight/viscosity, does make a difference, as do the sum of all the other parts. 

Happy to I answer more questions, but there are a ton of combinations/variants that are available to mess with. 

Solid article here with some basics and other info. 

https://jdmfishing.com/an-introduction-to-modern-daiwa-magforce-braking-by-ryan-higgins/