Originally Posted by
CliffordK
That opens a whole new can of worms.
The vintage roadbikes all had 1" forks. Vintage MTBs had 1 1/8" forks.
You can, of course, get 1" threadless forks and headsets. And maybe 1" spacers. But, then the selection of 1" threadless stems is limited, so you'll probably end up with a 1 1/8" threadless stem and shims.
Anyway, if I was going to replace the fork anyway (steel ==> CF, building up forkless frame, etc), then I might consider converting from original threaded to threadless.
Otherwise, I'd probably stick with the threaded + adapters.
Or, just use the quills that have worked for ages. I put a winged handlebar on one bike necessitating a 2-bolt open faced stem, but somehow I accidentally found a 26.0 winged handlebar (which apparently is relatively rare now). And, there are a few quills that take the 26.0 bars with a 2 bolt face.
Trek supplied 1" threadless forks on the 1993 2300 Composite bike. The only model year (and model) they did a threadless fork on Composite bikes. They also supplied some threadless 1" forks on some model year carbon bikes (but never on the bonded aluminum bikes from what I've found).
I played with the idea of converting some of my Trek bonded aluminum bikes to 1" threadless using original Trek threaded forks from larger frame bonded aluminum bikes. I figured that if I could find the fork from a really big Trek bonded aluminum frame, the steerer tube would be longer enough for me to hack off the threaded end of the steerer tube, and still have acceptable length on it to attach the threadless headset and stem with spacers (this would yield the largest choice of paint colors, plus the choice of chromoly or aluminum fork blades). Or maybe get the threadless 1" fork from a 1993 Trek 2300 (pretty rare and only came in one color) that is the same size frame as the Trek bikes I would be looking to convert.
Profile still makes 1" quill stems with 26mm handlebar clamps and 2-bolt clamps. I have one (in black) that the PO of my 97 Trek 1400 installed. From what I've seen they are available in polished silver (didn't see any of the black ones offered) on eBay. Personally, I think they look kinda clumsy (skinny post with large horizontal tubing and clamp), but that's my personal opinion.
I prefer the classic of the Cinelli, 3T, or Sakae single bolt quill stems.