Silca Speed Balance kit
What is it?
SpeedBalance is the world's first Aerodynamic Wheel Magnet AND tunable balancing system for high performance cycling. SpeedBalance replaces your spoke magnet with a rim mounted aerodynamic magnet that can save up to 1 watt at 30mph. 4 Tungsten slugs inside the SpeedBalance weigh 2.5 grams each allow for custom wheel balancing up to 10 grams to offset valve stem weight and create perfectly balanced wheels to eliminate high speed vibrations and improve handling.
SpeedBalance Kit comes with:
2x SpeedBalance Pods (each pod contains 1 magnet and 4 Tungsten slugs)
2x SpeedShield Aero Valve Stem Pod
Upgrading 2 Wheels with SpeedBalance and SpeedShield will save just over 1 Watt at 30mph, slightly more savings than upgrading that same wheelset to Ceramic Bearings.
Who Needs It?
Performance oriented cyclists with carbon wheels can all benefit from SpeedBalance. Balanced wheels improve handling, comfort and confidence, particularly on high speed descents, while the aerodynamic benefits of the SpeedBalance magnet over spoke mounted magnets results in a wattage savings equivalent to a full wheel ceramic bearing upgrade at a tiny fraction of the cost.
Who needs it?
"12 Years ago I developed the world's first 82mm wheel..for the time period, the wheel was pretty exotic, much deeper and wider than anything else, and of course, it was fast. The wheel was met with immediate and tremendous success, winning a Tour de France Stage in it's debut, an Olympic Gold medal, Ironman Kona and ultimately a Tour Milenstein Award in Germany (the Oscars of the cycling world) ..all within a few weeks of each other. It also created a total panic within the mechanic ranks over a topic that was previously thought not to be an issue for bicycle wheels. That topic: Wheel Balance.
As carbon wheels become deeper, the longer valve stems have created a growing imbalance problem for the wheel. The rims themselves are already 2-8 grams heavier at the valve hole as the hole has to be heavily reinforced with carbon to prevent collapse of the hole. Then the the inner tube overlaps/seam are at the valve, (in tubulars, the base tape also overlaps here), the valve stem has a 2 ply rubber reinforcement at the valve, and of course, the valve stem itself which is metal and therefore heavier than the carbon fiber in the rest of the wheel. In total, a 60mm deep wheel typically has 10-16 grams of imbalance at the valve which is barely noticeable to the rider, but an 82mm deep rim requires an additional 20-25mm of valve extender adding another 3-4 grams.
At high speeds the pro cyclists were complaining of an oscillation that wasn't quite a 'speed wobble' but was disconcerting. I found myself flying all over the world talking with these athletes and ultimately ended up buying small lead weights from an auto parts supply store and bonding them inside the wheels with epoxy. Turns out that 15-20 grams of imbalance at high speeds was a big deal." - Silca Website