Bearings used in YOYO need to rotate smoothly and freely, Runstar Bearing has a full dimention of Ball Bearings for YOYO, If you hold the inner ring with one hand and turn the bearing with the other hand, the bearing can rotate for 20 seconds at least, there are chrome steel(Gcr15) and stainless steel (440 or 420) for choice in Runstar, Custom-made products is accepted in Runstar. All Runstar’s Bearings are strictly controlled under ISO9001:2015.

PART NUMBERSEAL TYPEBore diameter(d)Outer diameter(D)Width(B)BALL SIZE(mm)BALL QTYweight(g)
R188open1/4"︱6.35mm1/2"︱12.7mm1/8"︱3.175mm1.588101.6
R188ZZShields1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
R188-2RSRubber seal1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
R188Uopen1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
R188UZZShields1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
R188Vopen1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
R188VZZShields1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
R188Topen1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
R188TZZShields1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
SR188open1/4"︱6.35mm1/2"︱12.7mm1/8"︱3.175mm1.588101.6
SR188ZZShields1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
SR188-2RSRubber seal1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
SR188Uopen1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
SR188UZZShields1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
SR188Vopen1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
SR188VZZShields1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
SR188Topen1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32
SR188TZZShields1/4"︱6.35mm1/2"︱12.7mm3/16"︱4.762mm1.588102.32