Worksman mover steerer tube size

[RebelPrinter]

I finally got around to picking up my trike project and need to order forks. The race for the steerer measures 29 and change mm clearance but it had a 25.4mm mountain bike fork in it. Would I be correct ordering a 1 1/8x8 steerer tube ?. It's going tripple-tree forks. It is a Worksman Mover of questionable heritage and history.

 

[Chalo]

1-1/8" and 1" forks aren't interchangeable. I mean, you can use reducer collars to put a 1" fork into a 1-1/8" frame, but that's a dumb backwards move. But there isn't enough room to fit a 1-1/8" headset into a 1" frame.

Some frames that were built around American/BMX 1" headsets are thick and chunky enough to ream the head tube from 32.7mm to 34.0mm for a more modern 1-1/8" fork. I have done this. But if your existing cups are for an ISO 1" headset (30.2mm cups) or a JIS 1" headset (30.0mm cups), this isn't likely.

Measure the bores in the head tube, measure the OD of the head tube at the ends. If the bore is 32.7mm and the OD is at least 37mm, you can consider using a 1-1/8" fork. You'll need help from a pro bike shop or a frame builder.