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I am not a bike expert, however I enjoy working on modern single speeds and beach cruisers, and learning as much as I can along the way. I have tried to teach myself, via the internet and by asking around at a few local bike shops, about this 1976 Sears Roebuck bicycle that I have, but I have not had much luck. I have never had a bike this old. Not knowing if this bike is complete, I have had trouble finding out which parts might be missing. Nonetheless, this is an incredible bike and I am eager to keep it in riding shape. I am open minded and truly appreciate all information and advice that you have to offer. Thanks!

This headset would get stuck when I would take turns from time to time but would always free itself back up naturally. Most recently, I took a turn and as the headset became stuck, several of the ball bearings (5/32 x 14B) from the lower headset became free and flew onto the street. Back home I disassembled the headset to find the ring, that holds the ball bearings, was torn up and some of the ball bearings were missing. Upon further inspection, I began to consider that some of the pieces from the headset were missing, meaning that I have been riding with an incomplete headset since I acquired the bike. This might explain two things: (1) that's the reason why the headset has been sticking? (2) that is why the ball bearing ring became destroyed?

Moving forward, I am seeking to get a new complete 1" threaded standard bicycle headset that would fit this bike. I am hoping this will fix the problem I have been dealing with. Are parts like these still available for this setup? If so, is one manufacturer better than another? And where is my best bet to look?

Sears Roebuck 1976 enter image description here enter image description here enter image description here enter image description here enter image description here

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    Aside from fitting the steerer tube (which you indicate is 1" threaded), the headset needs to fit into the head tube. That head tube from your photo seems as though it might be "oversized" and thus take something other than a standard-sized headset. Since you've already got the pressed-in cups in place, perhaps you can just clean the races, replace the ball bearings packed in grease and tighten things appropriately. The "ring that holds the ball bearings" may have just been a disposable cage. If you could post close up photos of all the top and bottom components of the headset it would help us
    – Armand
    Jun 23 at 7:04
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    All old-style, meaning cup and bearings are still available, mainly because there are just about standard and oversize types in those days. The possibly required tools should be stock of every decent LBS. But as @Armand writes, bearings, grease and a light hand with wrenches would most certainly sort out the problem. I personally have a vintage bike (80y+) that still runs on the old cups with only the bearings & grease replaced 30y ago. Those things usually last.
    – Carel
    Jun 23 at 17:24
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    Thanks for the photos - if you have some of the (now empty) head tube of the frame showing the cups on the top and bottom end, that would be great. The bottom bearings between the race at the crown of the fork do almost all the work, since the weight of the frame is pressing down on them. The upper bearing race system at the top of the head tube, with the top race, washers and hex locknut screwed on, serve mostly to keep things together.
    – Armand
    Jun 23 at 23:57
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    It looks to me like your upper race (angled shiny section) and that knurled disk are installed upside down. If you get new ball bearings (don't mix new with old) and install a set in the top cup with grease, then screw the top race down onto the bearings, then the knurled disk, perhaps the spacer, then the hex lock nut, I think you should be close. On the bottom, just put new bearings and grease between the fork crown race and bottom cup. Bottom line - you may get by with just a bunch of bearings and grease after careful cleaning.
    – Armand
    Jun 24 at 0:01
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The key to finding out the headset you require is obtaining the internal diameter of the headtube. The trouble here lies in the fact that to obtain the measurement the bearing cups need to be removed so just the frame's headtube bore is measured. This leaves the bike unrideable while a new headset is obtained unless one wants to press the old cups back in which makes little sense IMHO.

Measurement of the internal diameter of the headtube should be obtained with a caliper. Two measurements 90 degrees from each other should be obtained and then averaged to get the final headtube I.D. (aka: bore). The majority of bikes with 1" threaded headsets use the ISO standard for the headtube bore and crown race of the fork. This article from VeloOrange describes the standards and discusses some other details of threaded headsets. Essentially, you will likely find the ID of your bike's headset to be very near 30 -- 30.15mm. If so, you'll require an EC30/25.4 headset. This is the standard headset identification system (S.H.I.S.) used to correctly identify what headset is needed.

Park Tool's threaded headset service instructional has excellent tips on how to do the service as well as links to other articles about headsets, their standards and servicing them.

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