The IRD ScramJet incorporates a hybrid ceramic bearing system. This is a cartridge system that involves a single ceramic ball with the remaining balls being steel. These are encased within steel races.
Don’t confuse these with “other” hybrid ceramic bearing systems that use all ceramic balls with steel races. Steel ball bearings have advantages over ceramic other than just cost. They stronger than ceramic thus have higher load ratings. Ceramic balls are much harder than steel balls, but this also means they are more brittle, thus their lower load ratings than steel bearings.
The Scram-jet was built with strength and durability as its design goal. The Scram-jet combines the strength of steel and uses the hardness of ceramic to extend the bearing life of the stronger steel.
When a contaminate enters, the extremely hard ceramic ball will pulverize it rendering it harmless within the bearing system. Furthermore, if the race has been damaged by sand or any other contaminant the extremely hard ceramic ball will cold work the steel race; contingently polishing it with every rotation, actually repairing the surface. Although this might seem too magical to believe, many other industries use this technology to dramatically increase bearing life by several times. They are sometimes referred to as self healing bearings.
• Aluminum cups and sleeve. Sleeve is expandable to fit shells 68mm to 100mm
• Self-cleaning Hybrid Ceramic Technology
• 5-year warranty on bearings
• English threading
• Fits 24mm axle cranks from Shimano, Race Face, FSA, etc.
• Anodized Red sleeve w/ Black or High-Polished Silver Cups
• Made in Japan by Tange-Seiki