Hacks / Bodges

1" threaded to 1 1/8 threadless conversion

This happened because I noticed that without the headset cups installed, an old 1" road bike has (barely) enough clearance to fit a modern fork. The problem is that there does not exist a suitable headset conversion so I had to make one. These are outboard mounting cups, pressfit on like normal. They were milled from 6061T6 and built pretty stout, total weight <100g. I calculated the difference in diameters between the 1 1/8 steerer tube and the head tube to be 1/10mm, giving 1/20mm clearance around the steerer. I had to file down some internal imperfections but despite the tolerances, the headset feels very smooth and rides great. The design of the cup and the bearing used raised the headtube by approx 5mm.

Though I kind of just remembered a critical detail that might make using this headset with another fork difficult - most forks taper out slightly at the bottom to fit the crown race, typically up to an inch. This particular one was straight to the bottom where there was a step for the race, I may not be able to insert most forks unless they have a very straight steerer design.

https://old.reddit.com/r/Frankenbike/comments/dk6m70/1_threaded_to_1_18_threadless_conversion/

I asked about doing this a while ago, @mdcc_tester told me off because of the increased levering action 😉 (not that he's wrong necessarily)

PS. not mine by the way