I prefer steel frames which usually come with threaded forks so threadless headsets are foreign to me. I recently purchased a niece piece of American handmade steel on craigslist (see below) and I am trying to figure out how to set it up. If it wasn't such a nice frame I would swap the fork for a threadless.

The frame came with a Chris King headset, 2 spacers, and some sort of shim over the exposed portion of the steerer tube. I assume the steerer tube is 1-1/8" as the stem cap says 1-1/8". Isn't that the standard size so why the shim? What measurements do I need to know to pick the correct stem for size 26 bars.? How do I get the most accurate measurement?

Last, there seems to be a little bit of side to side back and forth play/wiggle of the fork within the headset. Makes me worried that the headset diameter is not the proper size for the fork. Or if a little play is normal is thank going to make the bars jiggle?

Please educate me.

Are you sure what you see on top is not a threadless stem adapter inserted in a 1" threaded steerer? Or is the steerer 1 1/8" threadless?

Not sure as I have never used a threadless stem adapter. I have very little knowledge when it comes to threadless setup/parts. Are you thinking that the fork may be threaded but has an adapter to use as threadless? I checked out the the frame builders website https://bicycleframes.com/frames/ss_street/
All of the frames with that particular straight blade fork have a threadless setup so I think the fork must be threadless.

In that case the wigglejiggle will go away when you install the stem and set headset preload.

+1

Threadless systems aren't the same as threaded systems. Once you remove the stem the headset is no longer adjusted anymore.

I would like a non blurry picture of the top of the steerer/headtube area. It certainly does look like a threadless fork to me and not an adapter.

The top-cap threw me for a moment, but it does appear to be a threadless.

Correct installation of the stem - proper torque-setting from the manufacturer of the stem being followed - should have it runing perfectly tight with no more "wigglejiggle" to be seen.

Keep us informed.

it looks to me like you have: a nice looking steel frame with a 1" (one inch) steerer tube on the fork. the silver "shim" on the steerer is for using a 1 1/8" stem on the 1" steerer. and the seller supplied a 1 1/8" cap. the seller likely supplied the shim and cap since 1 1/8" stems are more common than 1" these days

That's what I noted on my first post to the OP., as it somewhat looked like to me like a threadless adapter.

OP: Disassemble the top part of the steerer tube and tell us what you see.

Looks like you guys were right 1" steerer tube with a shim to get it to 1-1/8" I think the headset is 1" and the jiggle is coming mostly from the bottom having a little room to move between the silver part and the black headset. Is there some sort of o-ring or washer in there that could wear out with use and cause the jiggle?

Once you put the stem on and get your spacers and steerer tube length as you like them, you tighten the top cap screw to set the preload. Setting the preload means you remove the play by tightening the screw (with the stem bolts not tightened), but leave it loose enouggh for the bike to steer freely without binding.

Honestly, you may be in over your head, from the sound of it. That's a very nice frame, fork, and a very expensive headset. Congratulations on such a nice find. A trip to your LBS and they will fix you up for not a lot of money and it will be done right. I bet they wouldn't mind explaining to you in person how all this works. Once you've seen it and understand it, it's no biggie.

no in your first reply you said it looked like a threadless adapter. not a shim to use on a threadless for a larger diameter stem.

OP: The seller left it in that fashion so all the bits and pieces won't come apart without the stem installed.
So, all you need is a threadless stem, preferably if you can find a 1" threadless stem to your liking. That way, you don't have to use that shim and overall will give you a less bulky look up there, especially on a nice frame like that.

I hear you. I'm not a roadie up with all the latest tech. I try to keep the bicycle simple. My bicycle is used to commute to work, supermarket, and around town. I have been riding the same old steel bike you see below for the past 6 years so that is what I know. There is one of those community bicycle repair shops I plan to head to. I am sure the mechanics will teach me what I need to know to set this frame up for years to come.

Can you recommend some 1" stems that may compliment the frame?

First thing I would do is toss that topcap and shim. The topcap is non original to that headset and looks like garbage. That headset is one of the nicest you can buy, a scratched up VP topcap does not belong there.

Also, you will have a ****load more options by reducing a 1 1/8 stem for your bike - 1" stems aren't as widely available or in the variety of 1/8 stems anymore. However, you may find searching for a 1" stem you like still worthwhile as you won't need to use a shim. Keep that possibility in mind.