Bearings for 1" threaded fork into 1 1/8" threadless headtube

Indyjps · Jul 6, 2022

Skip to post 9. 1-8 are flops

Was digging thru the headset pile and found the elusive bearing to allow a 1" threadless fork to be assembled into 1 1/8" threadless cups.

Fork crown 1"
Lower bearing cup 1 1/8"
Upper bearing cup 1 1/8"
Top bearing race 1" threaded, no lip on the bearing race side
Lock washer 1"
Lock nut 1"

The bearings are from 1 1/8" headset. The trick is 3/16 ball bearing diameter, 15 ball.

38mm - outside diameter
31mm - inside diameter
4.71mm 3/16" ball

It's mocked up and feels smooth.
I have NOT ridden this yet, need to cut down fork threads.

Indyjps · Jul 6, 2022

Bearings I'm using
38mm - outside diameter
31mm - inside diameter
4.71mm 3/16" ball

Looking around for same dimensions

This is interesting 1 1/8 bearings with 1/4" bearings - even bigger balls - YEAH

Captain Awesome · Jul 6, 2022

Interesting. I think I might have some old FSA pig sets around

Indyjps · Jul 6, 2022

Captain Awesome said:
Interesting. I think I might have some old FSA pig sets around

Would love to see how the bearings look.

Indyjps · Jul 7, 2022

1 1/8" with 1/4" ball bearing with sunlite pn.

Looks like the same bearing used in FSA PIG. Must have been a fairly standard bearing at one time.

Are these the mysterious "Murray" bearings

DonGiro20 · Jul 7, 2022

Thank you for this! This may help solve most of the problems I'm having finding a replacement headset for my Murray Monterey. Still need to find a replacement for that pesky crown race though. I'm using a threadless headset and fork for now.

Indyjps · Jul 7, 2022

Cut the fork and did a better mock up.

Got a little wobble when tightened down, ordered some of the 1/4 ball bearings. Mainly out of curiosity if this will work.

Will update thread and correct any misinformation when I have a working version.
Or.
Disprove my own theory if it doesn't work at all.

Bottom bearing feels and rolls well. Top bearing, I don't think I'm catching enough of the taper on the 1" headset bearing cone.

Indyjps · Jul 15, 2022

Got the 1/4" ball (15 ball) 1-1/8" headset bearings.

Indyjps · Jul 15, 2022

SWING AND MISS. Thread can be deleted, no new solutions.

Bearing needs to fit the taper on the fork crown and top nut well, that centers the headset.

Tried every combo of bearing - fork still rocked back amd forth.

Ground down the top headset cup to prevent the top nut from bottoming - nada.

Went back to method I've used in the past, that does work.
Grind a lead on the inner edge of the 1-1/8" cup, press the 1" headset cup into it. 3 welds, grind back