Choosing stabilizers for your recurve bow is more about personal preference than magic formulas. Rod length can be determined by your height, draw length, and how you want your bow to balance.
After passing the beginner stage, recurve archers eventually install a front stabilizer on their bow to help with balance and aiming. That stabilizer probably isn’t a high-modulus and ultra-stiff carbon rod, even though some newcomers go that route. Most, though, choose a fiberglass or aluminum stabilizer while learning how much weight feels comfortable on the front rod. In general, more draw weight and/or a longer draw length means more weight out front.
Again, no formula determines the weight. That should be tried and tested by each archer to learn what works best for them.
Choosing side rods, and an extension bar, depends mostly on how you want the bow to balance and react during and after the shot. Some archers prefer the bow to sit fairly neutral, with its center of gravity close to the grip. That’s usually accomplished by attaching longer side rods with no extension bar to the bow. The weights on the side rods sit in line or farther back than the bowstring. This setup tends to subdue the bow a little more on release and the bow just wants to sit still.
Other archers like their stabilizers to offset the center of gravity farther forward, creating a more front-heavy setup. That’s done with a longer extension bar and shorter side rods, which is more common on Korean and Japanese setups. It creates more stationary torque on the bow hand, which some archers prefer for aiming. This setup also lets the bow jump more aggressively from the hand upon release for a more dynamic shot.
With the stabilizers’ increased weight, an archer might think the rods feel floppy during the shot. That’s when you should try different stiffnesses in stabilizers. A lighter mass weight lets you use a more affordable stabilizer made of regular-grade carbon. Increasing the stabilizer’s stiffness requires a higher modulus carbon, and that usually doubles or triples the price.
Vibration is the next consideration when choosing dampers for your stabilizer. Archers usually install this softer medium between the bar and weights to reduce vibration. Dampers come in various shapes, sizes and, more importantly, stiffnesses. Stiffness variations depend on how much weight you attach; more weight requires a stiffer damper. Soft dampers bearing lots of weight sag, and don’t properly activate the damper.
Don’t get bogged down in the details of every stabilizer and accessory out there. Before buying a set of rods, try as many types as possible to ensure you choose what’s good for you. What works for one archer might not give the feel or reaction you prefer. Once you choose a setup you like, you’ll enjoy shooting a comfortably balanced bow that behaves for you.