Silca SpeedBalance weights counterbalance long stems

Modular-weight pod can save 1w, company claims

Silca is rolling out an adjustable, aerodynamic counterweight kit that offsets the weight of long valve stems used in tall carbon wheels. Dubbed SpeedBalance, the pod also doubles as a magnet for speed sensors. Silca claims the system can save a watt of power at 30mph.


According to Silca, as carbon wheels become deeper and valve stems become longer, and thus heavier, light carbon wheels become more susceptible to imbalance — particularly at high speeds.

The kit consists of four weights and a magnet, housed in a aerodynamic body

The $36 / £28 / AU$47 SpeedBalance kit consists of two SpeedBalance pods, with profile similar Silca’s aerodynamic SpeedShield valve extenders, which are also included. Each pod comes with four 2.5g tungsten slugs and a magnet. The tungsten slugs can be added or removed to add weight to the opposing side of the rim, to offset the weight of the valve stem.

The SpeedBalance pod is held in place with 3M adhesive designed to adhere to carbon.

Check out this video of the SpeedBalance in action.

Silca claims that upgrading a pair of wheels with the SpeedBalance kit will save just over one watt at 30mph — slightly more savings than upgrading that same wheelset to ceramic bearings, the company claims.

The SpeedBalance uses a 3M adhesive to stick to carbon rims

The SpeedBalance kit is available now. Visit for more information.