1. The Hybrid bearing 6901 (weight 42gms per wheel set) has a steel inner & outer ring & assembled using a full set of Silicon nitride balls. (stock item)
2. The Zirconia bearing 6901 is similar in make up as the hybrid weighing 33% less.
3. The Full Silicon Nitrite bearings (as shown in the photo) are 58% lighter than the Hybrid as the outer & inner rings are all made from silicon nitrite. (Material Si3N4) (stock item)
Ask for a quote on 2 & 3 when ordering your wheels of choice.
