The steering bearings take a lot of pressure, but unlike wheel bearings they just go back and forth rather than spinning. This leads to grooves wearing in the outer race, a typical wear pattern (see photo).
Removing the outer races requires the use of a puller tool although there are other ways to do it (see below). I used the Kukko Puller which I purchased from Boxer2Valve. An alternative method of removing the outer races is running a bead of weld around the inner surface. As it cools it causes the race to contract and then they fall out. Some people have also drilled a small (5mm) hole through the frame to allow a drift to be passed and tap the race out.
Removing the lower bearing from the steering tube was tricky- I cut the wire cage and removed the rollers leaving behind the inner race sitting on the grease cup. However the bearing is an interference fit and doesn’t come off easily. I attacked it with a Dremel cutting disc and then split it with a cold chisel. This is the approach taken by William Plam at Boxer2Valve and it worked for me. Incidentally I highly recommend you watch all the Boxer2Valve videos on YouTube- William is an incredible mechanic and teacher. They also have a lot of good gear on their site.
To install the new bearing (the grease cup just slid on) I heated the bearing and then used a piece of stainless steel pipe which fit well to tap it down into place.
To install the new outer races I first meticulously cleaned the frame where the bearing sits. Then I put the race in the freezer for 15 minutes. Then the frame was gently heated and the race tapped in using a standard 50mm bearing driver.
