The spacer on my main suspension pivot is 1 or 2 mm wider than the distance between the edges the bearings would sit against if the spacer wasn't there. When I press in the bearings, the inner race of the bearings sit tight against the spacer.
What is the purpose of the spacer?
It's not for alignment (on my bike). It's not to keep out water or dirt (it's inside the carbon frame). It seems like a bad idea to me because it unnecessarily couples the bearings and creates a shear force which can’t be good for the bearings.
See diagram. There are two bearings on each side (green), spacer in middle.
by dogdevnull
2 Comments
If it’s the part I think it is, I believe it’s for preload on the bearings. If there is no preload, the rolling elements just scrub instead of rolling.
As I look at the image after I posted it, I think I see why. The spacer counteracts the compressive force of the pivot bolt.