If you’re following along the Metalworking 2 videos, you’ll have seen I had to destroy the lower steering stem bearing to get it off. That allowed me to strip the paint off the lower triple, and start working on fitting up the head light.
I didn’t want to knock a brand new bearing on right now (if I’ve already bought one, I can’t find it in the pile of parts I have) because this front end will be installed and removed at least 1000 times more during this build. Then I’ll have to paint the lower triple, and a bearing would be in the way.
Since I have a lathe, the best option was to take a scrap of aluminium and turn it into a shape that will approximate the bearing, and allow me to keep going.
This is not a high accuracy part, just a tapered “spacer” that will act like a bearing.
First I looked at the existing bearing. Any name-brand bearing will have the part number etched into it. The part number tells you the dimensions (they’re all standardised).
This is the top steering stem bearing:
From here it is straight to Google, where I turned up the details on Timken’s website:
I had to guess a little here, because the actual rolling diameter of the bearing isn’t specified, but I got close enough with some measurements off the cup that is pressed into the neck stem.
Then it was off to the lathe!
Done. Also fitted some flat drag bars as I think these will suit the lines of the bike best: