IRD ScramJet Bottom Bracket T47 Self-Cleaning 24/30mm In/Outboard

A supremely adjustable bottom bracket in the T47 threaded standard.
Fits both 24mm and 30mm crank axles, 68 -100mm BB shells, and  works as an outboard bearing, inboard bearing and asymmetric bottom bracket. Not for SRAM Dub (29mm), GXP (22/24mm), or Praxis (28/30mm).

Replaces these SKU's:

- Inboard BB for 86.5~92mm BB shell width for 24mm spindle cranks
- Inboard BB for 86.5~92mm BB shell width for 30mm spindle cranks
- Inboard BB for 85.5mm BB shell width for 24mm spindle cranks
- Inboard BB for 85.5mm BB shell width for 30mm spindle cranks
- Outboard BB for 68-73mm BB shell width for 24mm spindle cranks
- Outboard BB for 68-73mm BB shell width for 30mm spindle cranks
- Asymmetric BB for 77-79mm BB shell for 24mm spindle cranks
- Asymmetric BB for 77-79mm BB shell for 30mm spindle cranks

The IRD ScramJet  T47  incorporates a hybrid ceramic bearing system. This is a cartridge system that involves a single ceramic ball with the remaining balls being steel. These balls are encased within steel races.

Don’t confuse these with “other”  ceramic bearing systems that use all ceramic balls and steel races. Steel ball bearings have advantages over ceramic other than just cost.

They are 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 they have lower load ratings than steel bearings.

The ScramJet was built with strength and durability as its design goal. The ScramJet combines the strength of steel and  the hardness of ceramic to extend bearing life.

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; continually polishing it with every rotation, actually repairing the it.

Although this might seem too magical to believe, many other industries use this technology to dramatically increase bearing life by several times. They are some times referred to as self healing bearings.

– Precision machined and finished aluminum cups, spacers, and washers.
– Telescoping sleeve is aluminum, not plastic
– Hybrid ceramic sealed cartridge bearing: one ceramic ball in a cartridge with stainless steel balls. The harder ceramic grinds down any debris that might enter the bearing. The less brittle steel balls keep things rolling smoothly.
– Bearings sit inside the BB shell when cups are installed.
– Bearings have lightweight shields on the outside.
– Includes wave washers and spacers for 24mm and 30mm use
– In anodized black with red sleeve or high-polished silver with black sleeve