Details

I convert my 1990 Trek 1000 from a 1 inch threaded fork/headset to a threadless setup with a carbon fiber composite fork. The most common threaded forks have 1 inch steerer tubes. So you are limited when converting them to threadless to use a threadless fork with a 1″ steerer. A fork with a 1-1/8″ streerer just won’t work in a head tube made for a 1″ steerer in most cases. In this video, I actually use threaded fork with a long steerer, but I install is with a threadless headset. I would have used a true 1″ threadless fork, but they are not easy find for a decent price and I wanted to go with carbon fiber.
Be aware that some bikes have headtubes with weird dimensions. Like old Schwinns have threaded forks with 1″ steerers, but the head tube is an odd size so is not a good candidate for threadless conversion.