AbsoluteBlack Hollowcage Screed for Shimano Dura Ace 9250 12 S Black

Introducing the AbsoluteBlack Hollowcage Screed for Shimano Dura Ace 9250.Our revolutionary OSPW mono-plate design is the quietest, most efficient and most aerodynamic derailleur cage created to date. It’s the dawn of a new era for rear derailleurs. The HOLLOWcage u00ae OSPW derailleur clevis has a carbon-polymer mono-plate construction with oversized ceramic bearings and the quietest pulleys ever created.Details : Weight : 71 g Bottom ring color : Black Compatibility : Shimano Dura Ace 9250 Designed in England. Made in the EU Suitable for cassettes up to 34T. Materials used : Carbon fiber-polymer matrix, Aluminum 7075, Rubber, Ceramic. Box includes : Complete cage, locking ring tool, 2 spare ring rubbers.WHY IS THE HOLLOWCAGE SO SPECIAL ? Super quiet : over 5 to 7dB noise reduction compared to the original Dura-Ace clevis, a noise reduction of about 40%. The gear change is as good as with the original Dura-Ace.HOLLOWcageu00ae uses very high top pulley teeth, which gives the best possible shifting precision. It is more aerodynamic than the original screed and other oversized cages. It saves more watts than other screed. One of the lightest oversize screed on the market. First single plate construction of its kind. Special rubber xring slings dampen the impact of the chain on the tensioner teeth, thus eliminating engagement noise. HOLLOWcage, unlike other screed cage systems, uses all-ceramic, custom-made, abnormally large bearings that make the screed incredibly stiff. The bottom bearing alone is actually large enough to hold an 12D pulley. The bearing rings are made from 100% zirconium oxide ceramic and the balls from silicon nitride ceramic. The cage and seals are of course made of low friction polymer. The adjustable spring tension allows you to adjust the cassette size and chain length to find the lowest possible tension.HOW TO MOUNT THE HOLLOWCAGE :You should mount the screed with the lowest spring tension setting (first hole from the left). If you are using an 11-34T cassette in combination with 52/36T or larger chainrings, you may need to mount the screed with a medium spring tension setting (middle hole) to allow for chain growth, but only if the first position produces a loose chain in the smallest ratio.There is a 4 years warranty on the bearings.