BK-5055 | 1/4 inch Loose Ball Bearing

BK-5055 - 1/4 (0.25) Grade 5 Steel Balls - 50 pieces Loose ball bike parts are still out there, so Enduro carries the loose balls you need to complete the job. Grade 5 balls meet or exceed 5/1,000,000 tolerance of sphericity and is considered extremely round, to the point that most steel races can't even be ground to match that level of precision. This is the same level of ball that is found in Enduro ABEC-5 bearings. Only a few years ago, Grade 25 would be considered a very high grade ball, used only in the best hubs and bottom brackets. Today, Enduro's entry-level ABEC-3 bearings feature Grade 10 balls and then Grade 5 or Grade 3 as you go up in price and performance.