May 17, 2009, cyclekart progress: rear axle bearings
Here, I’m just beginning to cut out a 2.25 inch diameter hole in a frame rail to accept a bearing hanger.
Here, I’ve just completed cutting out a 2.25 inch diameter hole in a frame rail for a bearing hanger.
Here is the drilled out framerail with rear axle bearing hangers and bearing, and a couple of nuts and bolts with which to fasten it all together. Those are grade 5 bolts, not just any old random bolts you might find in Home Depot.
Here’s the bearing installed into the frame rail.
The bearings and bearing hangers are kind of interesting. The frame rails in the kart will not be parallel, and I had sort of wondered how the rear axle worked, as, by just looking at the thing without knowing how it works, you might think it required the framerails to be parallel in order to work. The outer surface of the bearing race is actually machined to conform to a spherical shape. The bearing hangers mate together in such a way that they enclose the bearing in a cage that is a section of a sphere. The bearing is free to rotate inside in all axes, like a gimbal, but cannot escape the cage. This is how the frame rails can easily be non-parallel but sill have the rotational axis of the bearings be parallel to the axle. It’s harder to explain than it is to understand if you’ve got the parts in your hands to play with.