I own a 1998 Serotta Colorado which came equipped with a threaded 1" fork and quill stem. I wanted to convert to threadless. What is the procedure?

Almost certainly your threaded fork is too short to take a threadless stem and many would say don't clamp a threaded section of fork anyways. You can get quill adapters to take a threadless stem. https://www.bing.com/images/search?q...cles&FORM=IGRE If you're determined to totally convert you'll need a new fork, stem, spacers and possibly some new handlebars as most threadless stems are made for larger diameter bars in the clamp area but there are still several stems still made for smaller bars usually found with quill stems.

Sorry for not specifying. I sold the original fork and purchased an aftermarket.

Is the new fork threaded or threadless?

Threadless. Carbon Ritchey Comp

Along with the new fork you will need a 1" threadless headset (the Cane Creek 40 is a good one), a threadless stem, matching handlebars, spacers as needed and a compression plug.

What HillRider means by matching handlebars is that the diameter of the bar matches the diameter of the stem clamp area...not necessarilly matching make/model/material.

-j

Yes, thanks for clarifying it. That's exactly what I should have written.

The listed fork comes with a compression plug. A nice thing about threadless stems is they can be used either way, ie mounted one way for a flatter stem,
and flipped over for a riser stem. Don't be too quick to cut the steerer tube, some thought or perhaps informed advice should go into determining the
mini-max length of the steerer. You can also use this as an opportunity to optimize housing length off the bar. Many bikes (IMO) have excess housing as it
is a LOT of trouble to optimize the housing length to just the right curve and angle of approach to the frame, but worth it for the appearance.